research article development of a lunar-phase observation...

Research ArticleDevelopment of a Lunar-Phase Observation System Based onAugmented Reality and Mobile Learning Technologies

Wernhuar Tarng1 Yu-Sheng Lin2 Chiu-Pin Lin1 and Kuo-Liang Ou1

1Graduate Institute of HumanResource and e-Learning Technology NationalHsinchuUniversity of EducationHsinchu 30014 Taiwan2Graduate Institute of Computer Science National Hsinchu University of Education Hsinchu 30014 Taiwan

Correspondence should be addressed to Wernhuar Tarng wtarngnhcueedutw

Received 18 March 2016 Accepted 8 May 2016

Academic Editor Miguel Torres-Ruiz

Copyright copy 2016 Wernhuar Tarng et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Observing the lunar phase requires long-term involvement and it is often obstructed by bad weather or tall buildings In this studya lunar-phase observation system is developed using the augmented reality (AR) technology and the sensor functions of GPSelectronic compass and 3-axis accelerometer onmobile devices to help students observe and record lunar phases easily By holdingthe mobile device towards the moon in the sky the screen will show the virtual moon at the position of the real moon The systemallows the user to record the lunar phase including its azimuthelevation angles and the observation date and time In addition thesystem can shorten the learning process by setting different dates and times for observation so it can solve the problem of beingunable to observe and record lunar phases due to a bad weather or the moon appearing late in the nightTherefore it is an effectivetool for astronomy education in elementary and high schools A teaching experiment has been conducted to analyze the learningeffectiveness of the system and the results show that it is effective in learning the lunar concepts The questionnaire results revealthat students considered the system easy to operate and it is useful in locating the moon and recording the lunar data

1 Introduction

Astronomy is an important area of natural science becauseits scope ranges over the stars and materials in the universeincluding all celestial bodies and their interaction as well asour living environmentsThe changes of celestial phenomenahave a great influence on our daily lives Thus observing themotion of celestial bodies such as the sun the moon andstars has been an essential part in astronomy education Inaddition astronomical observation can motivate students todevelop creativity and independent thinking by using scien-tific methods and inference skills to solve the problems andderive correct answers

Observing celestial bodies is an important topic in K12science and technology curriculums Students may think ofcelestial motions by observing the sun the moon and starsand then use scientific methods to induce the rules andcauses of their interaction Therefore the observation andinvestigation processes can enhance the critical thinking andproblem solving abilities of studentsThemoon is the nearest

celestial body to the earth so it is a suitable target forobservation By doing so students can realize that the lunarphase is periodic after observing the moon in a regular andlong-term manner They may discover the relative motion ofthe sun earth andmoonby observing the rising and falling ofthe sun and themoon Alternatively students can also under-stand the cause of lunar phases solar and lunar eclipses dayand night and the four seasons by operating the 3D modelof these celestial bodies

Observing the lunar phase requires long-term involve-ment and it is difficult when encountering the following situ-ations (1) a badweather often upsets the observation plan (2)tall buildings in metropolitan areas may obstruct observa-tion (3) impatient students sometimes fail to keep completerecords of the lunar phase (4) students often fall asleep whenthe moon appears late at night Besides it is difficult for stu-dents to infer that the lunar phase is regular and periodic fromthe recorded data especially when the data are not completeAll these factors prevent them from developing correctconcepts

Hindawi Publishing CorporationMobile Information SystemsVolume 2016 Article ID 8352791 12 pageshttpdxdoiorg10115520168352791

2 Mobile Information Systems

In addition to the difficulty in lunar observation studentsoften presume the motion of the sun earth and moon ina subjective manner and even their science teachers mayhave misconceptions [1] Besides a lot of elementary schoolstudents lack spatial concepts and their cognition has notreached the formal operation stage [2] If the learning activityis only for a short term without completing the whole obser-vation process students are unlikely to obtain correct lunarconcepts

To enhance the understanding of scientific concepts 3Dmodels are often designed to simulate the natural phenomenawhich are difficult or impossible to observe in the real world[3] Because computer simulation presents a simplified andvisible model for the situations mentioned above it canattract learnersrsquo attention and provide them with concreteconcepts about the simulated phenomena [4] Researchershave reported the success of computer simulation in support-ing inquiry and reasoning skills [5 6]Winn et al [7] assertedthat computer simulation has the potential to promote cog-nitive development and conceptual change more effectivelythan direct experiences Thus how to develop effectivesimulation software to assist students in learning science is aresearch topic worth investigation

Recently many studies are focused on learning astro-nomical concepts using simulation software developed withfriendly user interface for simulating celestial phenomenaThe software enables its users to observe the virtual sky andsearch for celestial objects for example Starry Night [8]and Google Sky Map [9] Tarng and Liou [10] developed aweb-based astronomy museum using the virtual reality (VR)technology for applications in elementary science educationHobson et al [11] discovered that it is effective to teach lunarconcepts using simulation software for 2nd and 3rd grade stu-dents Trundle and Bell [12] studied the effectiveness of inte-grating simulation softwarewith inquiry-based instruction toenhance the lunar concepts of preservice teachers Sun et al[13] proposed a 3D virtual reality model of the sun and themoon for e-learning at elementary schoolsThe experimentalresults show that studentsrsquo learning achievement is higherthan that of using the traditional class instruction

Although the available lunar simulation software is effec-tive a gap still exists between its operation and actual obser-vation Consequently students may have difficulty applyingtheir operational experiences on computers to real observa-tion For instance they do not need to know the azimuth andelevation angles when operating the simulation software ondesktop computersMoreover themotion in real observationsuch as raising hands for measuring the elevation angle andlifting head for finding the moon is replaced by operatingthe mouse and keyboard Without physical operation andsensory integration students may have a hard time adjustingto outdoor observation Besides there are no familiar objectson the ground to serve as reference points when usingsimulation software and students cannot develop the ability ofmeasuring the direction and elevation angles in real observa-tion

The lunar phase changes as the moon revolves aroundthe earth and the latter also revolves around the sun whilerotating by itself all counterclockwise Therefore spatial

concepts play an important part to affect students in learninglunar concepts Traditional teachingmaterials cannot providestudents with an effective method for obtaining correct lunarconcepts so students lacking spatial concepts may havedifficulty learning the cause of lunar phases by observing therelative motion of the sun earth andmoon If the simulationsoftware allows students to observe the moon in the sky andrecord the lunar phase and the related data easily it can alsobe used to show the lunar phase according to the relativepositions of the sun earth and moon and help studentsunderstand the cause of lunar phases

As the advance of information technologymobile devicessuch as the personal digital assistant (PDA) smart phone andtablet PC are integrated into educational applications As aresult learning activities are no longer confined to classroomteaching and they can be done anytime and anywhere usingany devices to achieve the goal of ubiquitous learning [14]Mobile learning refers to any forms of learning which takesplace when a learner is on the move or can move to a newplace and still remain connected to online learning resourcesthrough wireless networks Recently a large number ofmobile devices are equipped with powerful sensors such astheGPS electronic compass and 3-axis accelerometer to pro-vide the information of position time direction accelerationand so on to support the design of simulation software forapplications in different areas of education

Augmented reality (AR) is a view of the real world whereelements are augmented by computer-generated situations orobjects to enhance onersquos perception of reality In this way theinformation in real environments becomes interactive andcan thus be manipulated digitally and physically Besidesartificial information about the environments and virtualobjects can also be overlaid in the real world According toAzuma [15] AR is an evolution of virtual reality (VR)with thefollowing features (1) interacting with real and virtual envi-ronments (2) providing real-time feedback and (3) havingto be in 3D space Compared with the operation of VR ARintegrates a real environment with virtual objects to enhanceonersquos comprehension and the sense of reality in a moreinteractive way Recent research has shown that applicationsof AR in learning activities can improve studentsrsquo knowledgeconstruction and engage learners in high flow experiencelevels [16ndash18] Therefore it can be used as an effective tool topromote science learning [19ndash22]

In general the implementation of AR can be categorizedas (1) the traditional AR which requires a marker for posi-tioning for example theMagic Book [23] (2) the ARwithoutamarker inwhich positioning is done byGPS or image detec-tion and (3) the AR combining amarker and image detectionfor positioning AR can increase interaction with the realworld and provide useful information not directly availableThis study is aimed at applying AR and mobile learningtechnologies to develop a lunar-phase observation systemThe main objective is for the user to see the virtual moon byholding the mobile device towards the real moon even if it isobstructed by a bad weather or tall buildings Also the lunarphases can be recorded for displaying the moonrsquos track andthe relative positions of the sun earth andmoon to study thecause of lunar phases

Mobile Information Systems 3

In 1970 the concept of context awareness was proposedby United States Department of Defense using GPS to obtainthe userrsquos location for providing various services [24] Itsmain idea is to satisfy the userrsquos sensational requirement byupdating necessary information according to environmentalchanges such as the time and position [25] The theory ofsituated learning [26] emphasizes that learning is uninten-tional and knowledge has to be presented in real situationsIts main idea is to provide a realistic environment for learnersand the acquired knowledge can be applied in a similarcontext Therefore if learners wish to construct knowledgeabout lunar concepts they should deal with the situationsthat occurred in the real world By doing this the obtainedknowledge is more meaningful and thus can be applied inpractical situations

Based on the modes of representation proposed byBruner [27] the initial phase of the cognitive process isenactive representation where learners integrate actions intocognition in order to learn by doingMoreover theymay turnthe outside world into images signs and symbols to interpretthe obtained knowledge in an abstract or a logical way In thisway learners can understand and acquire knowledge easilyand store it in long-termmemory which may enable them tolearn better in the future and develop the transfer of learningAccording to relevant studies [28 29] it was discoveredthat actions can attract learnersrsquo attention and enhance theirlearning Thus it is believed in this study that the integrationof AR and physical operation in observing lunar phases canhelp students develop lunar concepts and store in long-termmemory to make learning more effective

Currentlymobile applications for learning lunar conceptsare mainly focused on the display of lunar phases Forexample Lunafaqt [30] allows its users to see the instant lunarphase and also for the entire month based on current (orinput) date time and location Among the applications inastronomy education Google Sky Map allows the user to seta different date time or location for displaying the moonin addition to the celestial bodies such as constellations andplanets as well as some astronomical phenomena Howeverthese two applications are not designed for learning lunarconcepts and neither can they record the data of lunar phasessuch as the lunar calendar azimuth and elevation anglesMoreover they cannot display the moon track in the sky andthe lunar phases according to the relative positions of the sunearth and moon using the recorded data to help the userunderstand the cause of lunar phases

In this study a lunar-phase observation system is devel-oped using the AR technology and sensor functions ofGPS electronic compass and 3-axis accelerometer onmobiledevices to help students observe and record lunar phasesWhen the user holds the mobile device towards the moonrsquosposition the screen will show the virtual moon overlappingthe image of real moon (Figure 1) The compass will showthe azimuth of the moon and its elevation is obtained fromthe 3-axis accelerometer and listed on top of the screen Thesystem allows the user to record the lunar phase and itsazimuthelevation angles as well as the observation date andtime The system can shorten the learning process by settingdifferent dates and times for observation and it can solve

Figure 1 The lunar-phase observation system

the problem of being unable to observe and record lunarphases due to bad weather or obstruction by surroundingtall buildings In addition the physical operation in obser-vation can leave a deeper impression on learners to storethe obtained knowledge in long-term memory A teachingexperiment has been conducted to investigate the learningeffectiveness of elementary students by using the lunar-phaseobservation system as a tool for learning lunar conceptsA questionnaire survey has been conducted to analyze theattitudes of students after using the system and the resultscan also be used as a reference for improving the system

2 System Design

The lunar-phase observation system is developed usingShiva3D and 3ds Max based on the data obtained fromTaipei Astronomical Museum In addition the tools of JDKAndroid 15 SDK Eclipse and Android Development ToolPlug-in are also required for programming the sensor func-tions of GPS electronic compass and 3-axis accelerometeron mobile devices After the system is completed Shiva3DrsquosAuthoring Tool is used to convert it into the installation(APK) file for uploading to Google Play The testing envi-ronment is Android 40 installed on an ASUS tablet PC Thesystem modules include the 3D model of the sun earth andmoon (for calculating the moonrsquos position) camera controland time control interactive user interface GPS electroniccompass 3-axis accelerometer and API programs (Figure 2)The camera is used to observe the moon in the sky to verifythe correctness of the virtual moonrsquos position However thesystem can still be used if the realmoon cannot be seen due toa bad weather condition To record the lunar phase the usersimply holds the mobile device towards the moonrsquos directionuntil its image overlaps the virtual moon on the screen A redcircle will appear to surround the virtual moon and then theuser can press the button to record the lunar phase and itsdata

21 3D Model of the Sun Earth and Moon The 3D modelof the sun earth and moon is developed according to theirrotation periods and revolution periods and controlled by theequation about planetary motion (ie Keplerrsquos second law)


GPS

API

Electroniccompass

3-axisaccelerometer

ElevationN

W

E

1 2 3 4 5 6 7

S

NW

Locate the moon Display the lunar phase

Azimuth

Date time Display the 3D model Display moon trajectory

Longitude latitude

Recording (lunar phase date time azimuth elevation)

nmiddot middot middot

Figure 2 The architecture of the lunar-phase observation system

which governs the earthrsquos revolution around the sun andthe moonrsquos revolution around the earth To simplify thedesign process we set the sunrsquos position at the center of thismodel In fact the sun situates at a focal point of the earthrsquoselliptic orbit and revolves around the center of the MilkyWay galaxy by a period of approximately 200 million yearsAs we only consider the relative motion between the earthand the sun using a simplified model can reduce the com-putation time in coordinate transformation between thesecomplicated coordinate systems

To calculate the rotation angle of the earth model perunit time we must know the time required for the earth torotate once (360 degrees) Traditionally a day (or solar day) isdefined as the time between two successive transits of the sunacross themeridian which is divided into 24 hours Howeverthe angle that the earth rotates for a solar day is slightly greaterthan 360 degrees because the earth is also revolving duringits rotation The time for the earth to rotate 360 degrees (alsodefined as a sidereal day) can be calculated as follows Sincethe earth makes a revolution around the sun in a year (36524days) each solar day the earth must turn about an additionaldegree to see the sun on meridian Therefore it takes about24 times 60361 = 4 minutes for the earth to rotate one degree soa sidereal day is only about 23 hours and 56 minutes

The moon is the nearest planet to the earth and itsaverage distance to the earth is 384400 kilometers about603 times the earthrsquos radius The moon is the satellite of theearth and its mass is about 12 that of the earth The moonrevolves around the earth and thus they also revolve aroundthe sun together By observing the change in lunar phasesthe interval between two full moons is approximately 295days Using the same method to calculate a sidereal day wederive that the moon takes 273 days to revolve 360 degrees

Sun MoonEarth5

∘9998400

Moonrsquos orbit

Earthrsquos orbit

23∘27

998400

Figure 3 The coordinate systems of the sun earth and moon

As a result the time for themoon to rotate one degree is about24 times 273360 = 18 hours Because the moonrsquos rotation andrevolution periods are the same we can only see the same faceof the moon from the earth

The moon revolves counterclockwise around the earthalong its orbit which does not overlap the ecliptic plane butis tipped by an angle of 5∘91015840 Also the axis of the earth modelis rotated by an inclined angle of 23∘271015840 between the orbitalplane and the equatorial plane As the moon spins on its axisthe axis itself wobbles like a gyroscope and its rotation periodis about 186 years Therefore the moonrsquos position in thesky is between 28∘361015840 south and 28∘361015840 north of the equator(Figure 3) We can derive the moonrsquos position in the earth-based and the sun-based coordinate systems after the earthrsquosposition has been determined

The 3Dmodel of the sun earth and themoon for display-ing their relative motion and lunar phases can be developedby the computer simulation (Figure 4) We have designed thecontrol program using Shiva3D which obtains the currenttime from system API programs to determine the positionsand rotation angles of the earth and the moon in the sun-based coordinate systemThen we rotate the earthmodel andthe moonrsquos revolution orbit by their inclined angles Finally


Figure 4 The 3D model of the sun earth and moon

the center of the moonrsquos revolution orbit is transformed tothe earth center such that both their positions are calculatedin the sun-based coordinate system After the new positionsof the moon and earth have been obtained their rotationalangles must also be computed before the rendering processtakes place We set up two cameras one from the outer spaceand the other at the userrsquos GPS coordinates on the earthmodel to display the motion of earth and themoon as well asthe change of lunar phases

The completed lunar-phase observation system can beexecuted on Android mobile devices Science teachers candownload it from Google Play and install on their smartphones or tablet PCs for teaching applications The systemis designed based on the learning units of ldquoLunar phaseobservationrdquo and ldquoThe sun earth and moonrdquo in K12 Scienceand Life Technology Curriculum [31] for 4th and 9th gradersrespectivelyThe objective of the former is to understand thatthe lunar phase is periodic by observing the moon in a long-term and regular manner the objective of the latter is todiscover the rising and falling of the moon and the changeof lunar phases by the relative motion of the sun earth andmoon

After starting the system the user can see themainmenuincluding the buttons of Observe Lunar Phase Record LunarPhase and Exit (Figure 5) The system is designed withfive major functions (1) locating the moon and displayingits lunar phase (2) setting the system date and time (3)recording the lunar phase (4) displaying themoon track and(5) showing the lunar phase according to the relative positionof the sun earth and moon At the beginning the systemobtains the data of current position (from GPS) and date andtime (fromAPI) By clicking the buttonObserve Lunar Phasethe system will activate the electronic compass and 3-axisaccelerometer tomeasure the azimuth and elevation angles ofthe mobile device

22 Locating the Moon The system uses a blue arrow toindicate the moonrsquos direction in the sky (Figure 6) As soonas the moon is located a red circle will appear to surroundthe moon (Figure 7) After that the user can click the RecordLunar Phase button to record the lunar phase and its relevantdata The user can also click the Record Data button to check

Figure 5 The main menu of the lunar-phase observation system

Figure 6 The arrow showing the moonrsquos direction

the recorded data To prevent from pressing the button acci-dentally the system can only record the lunar phase when themoon is inside the red circle Also it will show the messageldquoSuccessrdquo or ldquoFailurerdquo to notify the user if the lunar phase isrecorded successfully or not

23 System Date and Time The user can change the systemdate and time by clicking the Set Date and Set Time buttonsand the current time can also be restored by clicking thecurrent time button (Figure 8)

24 Recording the Lunar Phase By clicking the Record Databutton on themainmenu the user can record the lunar phasehourly or daily and the systemwill record the lunar phase andits relative information including azimuth angle elevationangle date time and position accordingly (Figure 9) Afterrecording the data the user may convert them into organizedand meaningful information with the functions of displayingthe moon track in the sky and showing lunar phases accord-ing to relative positions of the sun earth and moon to helpthe user understand the lunar concepts

25 Displaying the Moon Track By clicking the button ofDisplay Moon Track the system will show the lunar phasesby the order of recorded times in one day (Figure 10) Whenclicking the data displayed on top of the screen the user willsee the corresponding lunar phase shown in Figure 10 Thisfunction allows the user to see the different positions of themoon in the sky and the variation of its azimuth and elevationangles as time changes


Figure 7 Locating the moon inside the red circle

Figure 8 Change the system date and time

26 Cause of the Lunar Phase The system has a built-in 3Dmodel to simulate the relative motion of the sun earth andmoon which can be used to illustrate the cause of lunar phase(Figure 11) By clicking the Start button the system will applythe recorded data to the 3Dmodel to demonstrate the cause oflunar phases with the perspective view from the outer spaceThe user can see the relative positions of the three planets andthe corresponding lunar phase and its related data

3 Teaching Experiment

In this study a teaching experiment has been conducted atan elementary school in Taichung Taiwan for more than amonth to analyze the learning effectiveness of students byusing the lunar-phase observation system for learning lunarconcepts Two classes of 4th graders were randomly selectedas experimental samples one as the experimental group (27students) and the other as the control group (29 students)This study adopted the ldquononequivalent groups pretest andposttestrdquo design to analyze whether the system could enhancethe studentsrsquo learning effectiveness about lunar conceptsIn this experiment the independent variable is teachingmethod the covariant is studentsrsquo knowledge about lunarconcepts before learning the dependent variable is theirknowledge about lunar concepts after learning the controlvariables are the teacher instruction time and learning con-tents A questionnaire survey and interviews with studentshave been conducted to understand the attitudes of experi-mental group students after using the system and the resultscould also be used as a reference for improving the system

The flowchart of the teaching experiment is shown in Fig-ure 12

31 Research Tools The research tools used in this studyinclude the lunar-phase observation system the achievementtest of lunar concepts a questionnaire survey and interviewson the issue of system acceptance The questionnaire wasdesigned according to Likertrsquos [32] five-point scale (stronglyagree 5 points agree 4 points no opinion 3 points disagree2 points strongly disagree 1 point) There are 20 questionsdivided into 5 parts basic information ease of use usefulnessuserrsquos attitudes and willingness of using the system Beforethe survey the questions were reviewed and modified bytwo experts to enhance the correctnessThe overall reliabilityCronbachrsquos 120572 = 089 gt 07 indicating the questionnaireis highly reliable The interviews were conducted after theexperimental group had completed the lunar-phase observa-tion Six students were purposively selected from this groupas interviewees two with the most progress two with theleast progress and two with the most observation recordsThe interviews weremainly about the feedback from studentsafter using the system and the results were recorded withtheir approval

32 Learning Objectives The teaching materials were devel-oped according to the learning unit ldquoLunar phase observa-tionrdquo and the achievement test of lunar concepts was designedbased on the textbook workbook and teacherrsquos guide fromthree textbook publishers in Taiwan The researchers talkedwith some science teachers to decide the learning contents asthemisconceptions in lunar phases commonly seen from ele-mentary students and the practical issues duringmoon obser-vation as well as the learning topics covered by the abilityindicators as listed below

(i) understanding the concepts that the moon appearslater day by day and it is closer to the east whenobserved at the same time for the day after

(ii) understanding the relation between the lunar phaseand the lunar calendar

(iii) knowing the names of lunar phases and their relationwith the lunar calendar

(iv) knowing the sequence of lunar phases and discover-ing that they occur periodically

(v) knowing how to observe the lunar phase and recordits related data

33 Teaching Activity Before the teaching experiment thestudents in both groups took the pretest Then they beganto observe the moon for one month The experimentalgroup used the lunar-phase observation system developedin this study (Figure 13) and the control group followed thetraditional observation method and recorded lunar phaseson a worksheet After the experiment both groups took theposttest Their scores were analyzed to see if the lunar-phaseobservation system could achieve better learning effective-ness than that using the traditional method A questionnairesurvey and interviews were further conducted to investigate


3 starsrsquo trackLunar phase

Lunar phaseLatitude

Longitude

AzimuthTime

Lunar calendarDate

Elevation

One-day moon trackExit

Next pagePrevious page

Figure 9 Recording the lunar phase and its relative information

Lunar phase

Exit

Figure 10 Displaying the moon track in the sky

Figure 11 The 3D model to demonstrate the cause of lunar phases

the attitudes of students after using the system The datacollected in this experiment includes (1) pretest scores (2)posttest scores (3) questionnaire results and (4) interviewresults from the experimental group Finally the achievement

30min

40min

30min

10min

40min

1 month

Interview

Questionnaire survey

Lunar phase achievement test (posttest)

Lunar phase observation and recording

Teaching how Teaching traditionalway of outdoor

observation

Lunar phase achievement test (pretest)

Experimental group Control group

for observationto use the AR system

Figure 12 Flowchart of the teaching experiment

test scores were analyzed by the independent samples 119905-test paired samples 119905-test and ANCOVA The questionnaireresults were processed by accumulative statistics

34 Learning Effectiveness To assess studentsrsquo prior knowl-edge about lunar concepts before the teaching experimentan independent samples 119905-test is conducted according to theirpretest scores Before that the assumption of homogeneity ofvariance has to be met so the data are analyzed by Levenersquostest and the results show that 119891 = 185 and the significance119901 = 018 gt 005 indicating no significant difference andthus satisfying the homogeneity of variance After applyingthe independent samples 119905-test to analyze the pretest scoresof the two groups the 119905 value is computed as 041 and the sig-nificance 119901 = 069 gt 005 which is higher than the standardof significance difference In other words the pretest scoresfor both groups have no significant difference and their abili-ties in lunar concepts are about the same This study adopted


Table 1 Paired samples 119905-test results of the experimental group

Average S D Progress 119905 value SignificancePretest 4089 1383 755 minus272 001Posttest 4844 1409

Figure 13 Using the lunar-phase observation system to conductlearning

the paired samples 119905-test to examine if the experimentalgroup made significant progress in learning lunar conceptsAccording to the results in Table 1 the average pretest scoreof experimental group is 4089 and the average posttest scoreis 4844The 119905 value is computed as minus272 and the significance119901 = 001 lt 005 indicating that the experimental grouphas made significant progress after using the lunar-phaseobservation system for learning lunar concepts

This study also used the paired samples 119905-test to examineif the control group made significant progress in learninglunar concepts According to the results inTable 2 the averagepretest score of control group is 3862 and the average posttestis 3917 The 119905 value is computed as minus024 and the significanceas 119901 = 081 gt 005 indicating that the control group did notmake significant progress by using the traditional method forlearning the lunar concepts

This study applied a one-way ANCOVA to analyze if thelearning effectiveness of these two groups has a significantdifference after the experiment In this analysis the teachingmethod is the independent variable the pretest score is thecovariance and the posttest score is the dependent variableBefore conducting the ANCOVA it is required to meet theassumption of the homogeneity of variance andwithin-groupregression coefficientThis study used Levenersquos test to analyzethe homogeneity of variance and the results show that thesignificance 119901 = 098 gt 005 satisfying the assumption of thehomogeneity of variance As for the homogeneity of within-group regression coefficient the significance 119901 = 016 ishigher than the significance standard In other words there isno significant difference and the ANCOVA can be conductedto see if a significant difference exists in learning effectivenessbetween these two groups

The ANCOVA results in Table 3 show that 119891 = 532 and119901 = 0025 lt 005 A significant difference exists betweenthe two groups after the experiment Since the experimental

Table 2 Paired samples 119905-test results of the control group

Score Mean S D Progress 119905 value SignificancePretest 3862 1681 055 minus024 081Posttest 3917 1790

Table 3 ANCOVA results of learning effectiveness for the twogroups

Source S S D F M S 119865 SignificanceGroup 83457 1 83457 532 0025Error 831344 53 15686

grouprsquos progress is 755 and that of the control group is only055 it can be inferred that the experimental groupperformedbetter than the control group in learning lunar concepts

35 Questionnaire Results A questionnaire survey was con-ducted to analyze the attitudes of students after using thelunar-phase observation system and the results are summa-rized in the following (the average score of the 5-point scaleis noted by 119878)

351 Basic Information Regarding the frequency of usingthe system 60of the students observed the lunar phase onceor twice a day 25 of the students conducted observation atleast five times a day As for the time spent on observationmost students spent less than 10 minutes per day and 50of the students spent less than 5 minutes indicating that thestudents used the system frequently but without spending toomuch time in observation

352 Ease of Use Most students agreed that ldquoThe userinterface is easy to understandrdquo (119878 = 46) and ldquoLearning tooperate the system is easyrdquo (119878 = 46) Only a few students didnot know how to use the arrow head as guidance to locate themoon at the beginning Some other students suggested that itwould bemore convenient if the system allowed them to con-nect to the Internet for obtaining information about the lunarphase and submitting their feedback for discussion

353 Usefulness Most students agreed that ldquoThe systemhelps me record lunar phasesrdquo (119878 = 455) and ldquoThe systemis useful in finding the information about lunar phasesrdquo (119878 =455) Besides they thought the system is more helpful indistinguishing the first quarter moon from the last quartermoon

354 Userrsquos Attitudes Most students agreed that ldquoI like to usethe system to observe the moonrdquo (119878 = 46) and ldquoI consider itworthwhile to observe themoon using the systemrdquo (119878 = 455)Students were impressed by the instant display of the lunarphase and they considered it useful to observe the moonusing the system Since the system can be used indoors theythought the observation is not affected byweather conditions

355 Willingness of Using the System Most students agreedthat ldquoI will use the system if I have to observe and record


(Date 61sim67)

Lunar phase recordThe 3rd week

Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)

Figure 14 The lunar data recorded by Student A and Student B

lunar phasesrdquo (119878 = 465) and ldquoI will consider using the systemfirst when neededrdquo (119878 = 445) Compared with the traditionalobservationmethod students would like to use the system forlearning lunar concepts because in the past they could onlyobtain knowledge from textbooks and now the observationcould be done anytime and anywhere In addition theythought the azimuth and elevation angles could be recordedeasily without using a compass or an elevation indicator

356 Usability Metrics (Observation Days and CompletionRate of the Observation Assignment) The system can be usedto observe and record lunar phases anytime and anywhereand it is not affected by the weather condition or the timewhen the moon appears According to the experimentalresults the average number of observation days within amonth (31 days) for the experimental group is 178 days andthat of the control group is only 46 days Also the completionrate of observation assignment for the experimental group(574) ismuchhigher than the completion rate of the controlgroup (149)

36 Findings in the Experiment The teaching activities forboth groups were conducted in classroom The teacherdemonstrated the skills for observing themoon to the controlgroup first and gave each student a worksheet to record thelunar phases within a month The experimental group stu-dents downloaded and installed the lunar-phase observationsystem on their tablet PCs before the teaching activity Afterthat the teacher demonstrated the major functions of thesystem and its operating procedure to them Since the controlgroup used the worksheet for recording the lunar phasessome students were bored when the teacher was explainingthe details about how to record the lunar phase on theworksheet Some students were not familiar with the way ofrecording the lunar phase and thus made a lot of mistakesThe experimental group students were interested in operatingthe system and they could not wait to raise tablet PCs to locate

the moon before the teacher finished the instruction More-over they were very active in asking questions about thesystem during the class

To verify the accuracy of studentsrsquo observation recordsthis study consulted Taipei Astronomical Museum for theazimuth and elevation angles of the moon at 8 pm on June1st which were 1585 degrees and 475 degrees respectivelyFigure 14 shows the lunar phases and their data recorded byStudent A in the control group (a) and Student B in the exper-imental group (b) It can be seen that the azimuth and eleva-tion angles recorded by Student A were both wrong More-over the student could not draw the correct track of themoonin the sky It is possible that Student A did not use a compassand an elevation indicator to measure the azimuth and eleva-tion angles correctly Before the bedtime he could only drawthree lunar phases on the worksheet not enough to showthe complete moon track in the sky

The lunar data of Student B were recorded on the systemwhich show the detailed information about the lunar phasein each hour including the date and time in the general andlunar calendars as well as the azimuth and elevation angles Inaddition themoon track in the sky is shown clearly similar tothe one recorded byTaipei AstronomicalMuseumThereforeit can explain why students in the experimental group couldlearn lunar concepts better and easier than the control groupThemain reason is keeping correct and complete lunar data toshow the moon track in the sky and the cause of lunar phasesaccording to the relativemotions of the sun earth andmoon

To realize how the system could help students collectdata about lunar phases the statistics of observation days byboth groups are shown in Table 4 and Figure 15 where theaverage observation days for the experimental group are 178days with the minimum of 5 days and the maximum of 27days Sixteen students in the experimental group observed thelunar phase for at least 16 days and some of them even con-ducted observation every day On the contrary the averagenumber of observation days for the control group is 46 days


Table 4 Statistics of observation days for both groups

Group Students Minimum Maximum AverageExperimental 27 50 270 178Control 29 00 80 46

2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3

1ndash5 6ndash10 11ndash15 16ndash20 21ndash25 26ndash30

Stud

ents

Experimental groupControl group

Observation days

Figure 15 Statistics of observation days for both groups

with the minimum of 0 days and the maximum of 8 daysBesides 17 students in the control group observed the lunarphase for less than 6 days and none of themmade the obser-vation for more than 10 days On average the control groupobserved the lunar phase about once a week and there were2 students who did not conduct observation at all

A comparison of observation records by the two groupscan be found in Table 5 and Figure 16The average number ofrecords for the experimental group is 489 with theminimumof 6 records and the maximum of 285 records There were12 students in the experimental group with more than 36records indicating that the observation records were takenat least once a day On the other hand the average number ofrecords for the control group is 55 about once per week withthe minimum of 0 records and the maximum of 14 recordsBesides half of the control group students had nomore than 5records and what is worse there were three students withoutkeeping any records at all

To understand how the weather and time affected thetwo groups in observing the moon this study checked thetimetable of moon rise and daily rainfall data (Table 6)provided by the Central Weather Bureau (CWB) TaiwanApparently there was no chance to see the moon from May19th to 23rd because these dayswere close to the end of a lunarmonth Moreover it was raining from June 7th to 18th suchthat the control group could not observe the moon due toearly moonrise or bad weather during these days Howeverthe experimental group could continue observation using thesystem without being affected by bad weather or the late timeof moonrise

4 Conclusions

In this study a lunar-phase observation system is developedusing the AR technology and sensor functions on mobile




Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75

Figure 16 Statistics of observation records for both groups

devices to help elementary and high school students observeand record lunar phases The system allows them to observelunar phases in real situations by holding the mobile devicetowards the moonrsquos direction and the screen will show thevirtual moon overlapping the real moon The system has abuilt-in 3D model to simulate the relative motion of the sunearth and moon and it can convert the recorded data intothemoon track in the sky to establish connection between thelunar phase and the relative positions of the sun earth andmoon Therefore it can help students develop correct lunarconcepts especially for those lacking spatial concepts Alsothe physical operation during observation makes a deeperimpression on students so as to store the obtained knowledgein the long-termmemory In addition the system can shortenthe learning process by setting different dates and times forobservation and it can solve the problem of being unable toobserve lunar phases due to bad weather or obstruction bytall buildings Therefore it is an effective tool for astronomyeducation in elementary and high schools

A teaching experiment was conducted to analyze thelearning effectiveness of students using the lunar-phaseobservation system for learning lunar concepts A question-naire survey was also conducted to understand the attitudesof students after the teaching experiment The results ofachievement test show that the learning effectiveness of theexperimental group is significantly higher than that of thecontrol groupThe questionnaire survey and interview resultsreveal that most students preferred to use the system forobserving the lunar phaseThey considered the system usefulin terms of locating themoon and recording the lunar data Inadditionmost students agreed that the system is easy to oper-ate and they would like to use it again if they have a similarrequirement in the future Finally the future works for this


Table 6 Statistics of daily moonrise rainfall and students conduct-ing observation (20120519 to 20120618)

Date Moonrise Rainfall(mm)

Experimentalgroup

Controlgroup

May 19 0348 49 19 0May 20 0427 207 16 0May 21 0510 mdash 10 0May 22 0556 mdash 21 0May 23 0646 mdash 19 0May 24 0737 mdash 25 17May 25 0830 mdash 13 4May 26 0925 mdash 10 0May 27 1020 13 15 0May 28 1116 136 17 3May 29 1213 684 25 4May 30 1311 mdash 4 7May 31 1412 mdash 13 10June 1 1516 mdash 18 23June 2 1623 mdash 10 21June 3 1730 mdash 22 5June 4 1836 mdash 20 18June 5 1939 mdash 18 17June 6 2035 mdash 20 5June 7 2125 01 10 0June 8 2209 82 12 0June 9 2249 207 16 0June 10 2326 232 15 0June 11 mdash 387 20 0June 12 0001 701 20 0June 13 0036 09 9 0June 14 0111 333 14 0June 15 0147 62 11 0June 16 0226 29 14 0June 17 0308 47 16 0June 18 0353 11 9 0

study are listed in the following based on the experimentalresults and research findings

(i) The system was developed with Shiva3D which doesnot support Chinese input Thus it is expected thatthe version with the library of Chinese language orplug-in for Android to support Chinese input willbe released soon such that the researchers can developthe functions for students to write down their feed-back about lunar-phase observation in Chinese withtheir classmates

(ii) The functions to support online search and uploadrecorded data via wireless networks will be added tothe system such that the teachers are able to know thelearning progress of students and know if they haveencountered any problems in learning lunar concepts

(iii) In addition to the lunar-phase observation starsare also important celestial bodies for astronomicalobservation in the K12 science and technology cur-riculums Therefore this study intends to include thefunctions of star observation in the future tomake thesystem a more useful tool for astronomy education

Competing Interests

The authors declare that there are no competing interestsregarding the publication of this paper

Acknowledgments

The authors would like to thank the financial support bythe Ministry of Science and Technology (MOST) Taiwanunder the Contract nos 101-2511-S-134-002 and 104-2514-S-134-003

References

[1] M Calik and A Ayas ldquoA comparison of level of understandingof eighth-grade students and science student teachers relatedto selected chemistry conceptsrdquo Journal of Research in ScienceTeaching vol 42 no 6 pp 638ndash667 2005

[2] J Piaget and B Inhelder Memory and Intelligence Routledgeand Kegan Paul London UK 1973

[3] K C Trundle and R L Bell ldquoThe use of a computer simulationto promote conceptual change a quasi-experimental studyrdquoComputers amp Education vol 54 no 4 pp 1078ndash1088 2010

[4] T de Jong andW R Van Joolingen ldquoScientific discovery learn-ing with computer simulations of conceptual domainsrdquo Reviewof Educational Research vol 68 no 2 pp 179ndash201 1998

[5] Y J Dori and M Barak ldquoVirtual and physical molecular mod-eling fostering model perception and spatial understandingrdquoEducational Technology and Society vol 4 no 1 pp 61ndash74 2001

[6] K-E Chang Y-L Chen H-Y Lin and Y-T Sung ldquoEffects oflearning support in simulation-based physics learningrdquo Com-puters and Education vol 51 no 4 pp 1486ndash1498 2008

[7] WWinn F Stahr C Sarason R Fruland P Oppenheimer andY-L Lee ldquoLearning oceanography from a computer simulationcompared with direct experience at seardquo Journal of Research inScience Teaching vol 43 no 1 pp 25ndash42 2006

[8] Starry Night 2015 httpastronomystarrynightcom[9] Google SkyMap 2015 httpgroupsgooglecomgroupgoogle-

sky-map[10] W Tarng and H Liou ldquoThe application of virtual reality

technologies in astronomy educationrdquo Journal of AdvancedTechnology for Learning vol 4 no 3 pp 160ndash169 2007

[11] S M Hobson K C Trundle and M Sackes ldquoUsing a plane-tarium software program to promote conceptual change withyoung childrenrdquo Journal of Science Education and Technologyvol 19 no 2 pp 165ndash176 2010

[12] K C Trundle and R L Bell ldquoThe use of a computer simulationto promote conceptual change a quasi-experimental studyrdquoComputers and Education vol 54 no 4 pp 1078ndash1088 2010

[13] K-T Sun C-L Lin and S-M Wang ldquoA 3-D virtual realitymodel of the sun and the moon for e-learning at elementaryschoolsrdquo International Journal of Science and MathematicsEducation vol 8 no 4 pp 689ndash710 2010


[14] G J Hwang ldquoDefinition framework and research issuesof smart learning environmentsmdasha context-aware ubiquitouslearning perspectiverdquo Smart Learning Environments vol 1 no1 pp 1ndash14 2014

[15] R T Azuma ldquoA survey of augmented realityrdquo Presence Teleop-erators andVirtual Environments vol 6 no 4 pp 355ndash385 1997

[16] P Sommerauer and O Muller ldquoAugmented reality in informallearning environments a field experiment in a mathematicsexhibitionrdquo Computers and Education vol 79 pp 59ndash68 2014

[17] M B Ibanez A Di Serio D Villaran and C Delgado KloosldquoExperimenting with electromagnetism using augmented real-ity impact on flow student experience and educational effec-tivenessrdquo Computers and Education vol 71 pp 1ndash13 2014

[18] T H C Chiang S J H Yang and G-J Hwang ldquoStudentsrsquoonline interactive patterns in augmented reality-based inquiryactivitiesrdquo Computers amp Education vol 78 pp 97ndash108 2014

[19] H Sollervall ldquoCollaborative mathematical inquiry with aug-mented realityrdquo Research and Practice of Technology EnhancedLearning vol 7 no 3 pp 153ndash173 2012

[20] DM Bressler and AM Bodzin ldquoAmixedmethods assessmentof studentsrsquo flow experiences during amobile augmented realityscience gamerdquo Journal of Computer Assisted Learning vol 29no 6 pp 505ndash517 2013

[21] H-K Wu S W-Y Lee H-Y Chang and J-C Liang ldquoCurrentstatus opportunities and challenges of augmented reality ineducationrdquo Computers amp Education vol 62 pp 41ndash49 2013

[22] H-Y Chang H-K Wu and Y-S Hsu ldquoIntegrating a mobileaugmented reality activity to contextualize student learning of asocioscientific issuerdquo British Journal of Educational Technologyvol 44 no 3 pp E95ndashE99 2013

[23] M Billinghurst H Kato and I Poupyrev ldquoThe MagicBookmdashmoving seamlessly between reality and virtualityrdquo IEEE Com-puter Graphics and Applications vol 21 no 3 pp 6ndash8 2001

[24] J Schiller and A Voisard Location-Based Services MorganKaufmann San Francisco Calif USA 2004

[25] W N Schilit A system architecture for context-aware mobilecomputing [Doctoral thesis] Columbia University New YorkNY USA 1995

[26] J S Brown A Collins and P Duguid ldquoSituated cognition andthe culture of learningrdquoEducational Researcher vol 18 no 1 pp32ndash42 1989

[27] J S Bruner Toward aTheory of Instruction Harvard UniversityCambridge Mass USA 1966

[28] HGardner Frames ofMindTheTheory ofMultiple IntelligencesBasic Books New York NY USA 1993

[29] G E HeinConstructivist LearningTheory Institute for Inquiry1996 httpwwwexploratoriumeduifiresourcesconstructiv-istlearninghtml

[30] Lunafaqt 2015 httpwwwandroidpitcomappcomlunafaqt[31] Ministry of EducationK12 Science and Life Technology Curricu-

lum Standards Ministry of Education Taipei Taiwan 2014[32] R Likert ldquoA technique for the measurement of attitudesrdquo

Archives of Psychology vol 22 no 140 p 55 1932

Submit your manuscripts athttpwwwhindawicom

Computer Games Technology

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Distributed Sensor Networks


Advances in

FuzzySystems

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014


ReconfigurableComputing

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014


Applied Computational Intelligence and Soft Computing

thinspAdvancesthinspinthinsp

Artificial Intelligence

HindawithinspPublishingthinspCorporationhttpwwwhindawicom Volumethinsp2014

Advances inSoftware EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Electrical and Computer Engineering

Journal of

Journal of

Computer Networks and Communications


Hindawi Publishing Corporation

httpwwwhindawicom Volume 2014

Advances in

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Biomedical Imaging


ArtificialNeural Systems

Advances in


RoboticsJournal of



Computational Intelligence and Neuroscience

Industrial EngineeringJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Human-ComputerInteraction

Advances in

Computer EngineeringAdvances in



In addition to the difficulty in lunar observation studentsoften presume the motion of the sun earth and moon ina subjective manner and even their science teachers mayhave misconceptions [1] Besides a lot of elementary schoolstudents lack spatial concepts and their cognition has notreached the formal operation stage [2] If the learning activityis only for a short term without completing the whole obser-vation process students are unlikely to obtain correct lunarconcepts

To enhance the understanding of scientific concepts 3Dmodels are often designed to simulate the natural phenomenawhich are difficult or impossible to observe in the real world[3] Because computer simulation presents a simplified andvisible model for the situations mentioned above it canattract learnersrsquo attention and provide them with concreteconcepts about the simulated phenomena [4] Researchershave reported the success of computer simulation in support-ing inquiry and reasoning skills [5 6]Winn et al [7] assertedthat computer simulation has the potential to promote cog-nitive development and conceptual change more effectivelythan direct experiences Thus how to develop effectivesimulation software to assist students in learning science is aresearch topic worth investigation

Recently many studies are focused on learning astro-nomical concepts using simulation software developed withfriendly user interface for simulating celestial phenomenaThe software enables its users to observe the virtual sky andsearch for celestial objects for example Starry Night [8]and Google Sky Map [9] Tarng and Liou [10] developed aweb-based astronomy museum using the virtual reality (VR)technology for applications in elementary science educationHobson et al [11] discovered that it is effective to teach lunarconcepts using simulation software for 2nd and 3rd grade stu-dents Trundle and Bell [12] studied the effectiveness of inte-grating simulation softwarewith inquiry-based instruction toenhance the lunar concepts of preservice teachers Sun et al[13] proposed a 3D virtual reality model of the sun and themoon for e-learning at elementary schoolsThe experimentalresults show that studentsrsquo learning achievement is higherthan that of using the traditional class instruction

Although the available lunar simulation software is effec-tive a gap still exists between its operation and actual obser-vation Consequently students may have difficulty applyingtheir operational experiences on computers to real observa-tion For instance they do not need to know the azimuth andelevation angles when operating the simulation software ondesktop computersMoreover themotion in real observationsuch as raising hands for measuring the elevation angle andlifting head for finding the moon is replaced by operatingthe mouse and keyboard Without physical operation andsensory integration students may have a hard time adjustingto outdoor observation Besides there are no familiar objectson the ground to serve as reference points when usingsimulation software and students cannot develop the ability ofmeasuring the direction and elevation angles in real observa-tion

The lunar phase changes as the moon revolves aroundthe earth and the latter also revolves around the sun whilerotating by itself all counterclockwise Therefore spatial

concepts play an important part to affect students in learninglunar concepts Traditional teachingmaterials cannot providestudents with an effective method for obtaining correct lunarconcepts so students lacking spatial concepts may havedifficulty learning the cause of lunar phases by observing therelative motion of the sun earth andmoon If the simulationsoftware allows students to observe the moon in the sky andrecord the lunar phase and the related data easily it can alsobe used to show the lunar phase according to the relativepositions of the sun earth and moon and help studentsunderstand the cause of lunar phases

As the advance of information technologymobile devicessuch as the personal digital assistant (PDA) smart phone andtablet PC are integrated into educational applications As aresult learning activities are no longer confined to classroomteaching and they can be done anytime and anywhere usingany devices to achieve the goal of ubiquitous learning [14]Mobile learning refers to any forms of learning which takesplace when a learner is on the move or can move to a newplace and still remain connected to online learning resourcesthrough wireless networks Recently a large number ofmobile devices are equipped with powerful sensors such astheGPS electronic compass and 3-axis accelerometer to pro-vide the information of position time direction accelerationand so on to support the design of simulation software forapplications in different areas of education

Augmented reality (AR) is a view of the real world whereelements are augmented by computer-generated situations orobjects to enhance onersquos perception of reality In this way theinformation in real environments becomes interactive andcan thus be manipulated digitally and physically Besidesartificial information about the environments and virtualobjects can also be overlaid in the real world According toAzuma [15] AR is an evolution of virtual reality (VR)with thefollowing features (1) interacting with real and virtual envi-ronments (2) providing real-time feedback and (3) havingto be in 3D space Compared with the operation of VR ARintegrates a real environment with virtual objects to enhanceonersquos comprehension and the sense of reality in a moreinteractive way Recent research has shown that applicationsof AR in learning activities can improve studentsrsquo knowledgeconstruction and engage learners in high flow experiencelevels [16ndash18] Therefore it can be used as an effective tool topromote science learning [19ndash22]

In general the implementation of AR can be categorizedas (1) the traditional AR which requires a marker for posi-tioning for example theMagic Book [23] (2) the ARwithoutamarker inwhich positioning is done byGPS or image detec-tion and (3) the AR combining amarker and image detectionfor positioning AR can increase interaction with the realworld and provide useful information not directly availableThis study is aimed at applying AR and mobile learningtechnologies to develop a lunar-phase observation systemThe main objective is for the user to see the virtual moon byholding the mobile device towards the real moon even if it isobstructed by a bad weather or tall buildings Also the lunarphases can be recorded for displaying the moonrsquos track andthe relative positions of the sun earth andmoon to study thecause of lunar phases








2 System Design




GPS

API

Electroniccompass

3-axisaccelerometer

ElevationN

W

E

1 2 3 4 5 6 7

S

NW


Azimuth


Longitude latitude







Sun MoonEarth5

∘9998400

Moonrsquos orbit

Earthrsquos orbit

23∘27

998400


































Lunar phaseLatitude

Longitude

AzimuthTime

Lunar calendarDate

Elevation




Lunar phase

Exit




30min

40min

30min

10min

40min

1 month

Interview





observation



























(Date 61sim67)


Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)












2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in










2 System Design




GPS

API

Electroniccompass

3-axisaccelerometer

ElevationN

W

E

1 2 3 4 5 6 7

S

NW


Azimuth


Longitude latitude







Sun MoonEarth5

∘9998400

Moonrsquos orbit

Earthrsquos orbit

23∘27

998400


































Lunar phaseLatitude

Longitude

AzimuthTime

Lunar calendarDate

Elevation




Lunar phase

Exit




30min

40min

30min

10min

40min

1 month

Interview





observation



























(Date 61sim67)


Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)












2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in




GPS

API

Electroniccompass

3-axisaccelerometer

ElevationN

W

E

1 2 3 4 5 6 7

S

NW


Azimuth


Longitude latitude







Sun MoonEarth5

∘9998400

Moonrsquos orbit

Earthrsquos orbit

23∘27

998400


































Lunar phaseLatitude

Longitude

AzimuthTime

Lunar calendarDate

Elevation




Lunar phase

Exit




30min

40min

30min

10min

40min

1 month

Interview





observation



























(Date 61sim67)


Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)












2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in
































Lunar phaseLatitude

Longitude

AzimuthTime

Lunar calendarDate

Elevation




Lunar phase

Exit




30min

40min

30min

10min

40min

1 month

Interview





observation



























(Date 61sim67)


Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)












2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in























(Date 61sim67)


Date

TimeAzimuth

Shape

TrackSouth

East

WestEast

Lunar calendar

Elevation

(a)

Lunar phase

Exit

(b)












2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in






2

00

2

4

6

8

10

12

14

16

18

1

3

10

17

76

7

3


Stud

ents


Observation days





4 Conclusions





Records

0

0

2

4

6

8

10

1212

11

3 3 3

5

4

3

2 2 2

1 1 1

3

14

Stud

ents

1ndash5

6ndash1

0

11

ndash15

16

ndash20

21

ndash25

26

ndash30

31

ndash35

36

ndash40

41

ndash45

46

ndash50

51

ndash55

56

ndash60

61

ndash65

66

ndash70

71

ndash75

gt75







Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in






Experimentalgroup

Controlgroup






Competing Interests


Acknowledgments


References









































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in






























Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in



research article development of a lunar-phase observation...

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