towards a new era of cultural heritage

7/27/2019 Towards a New Era of Cultural heritage

http://slidepdf.com/reader/full/towards-a-new-era-of-cultural-heritage 1/7

Towards a New Era of Cultural-Heritage Recording and Documentation

Author(s): Robert WardenSource: APT Bulletin, Vol. 40, No. 3/4 (2009), pp. 5-10Published by: Association for Preservation Technology International (APT)

Stable URL: http://www.jstor.org/stable/40284498 .

Accessed: 15/04/2013 00:34

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of

content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

Association for Preservation Technology International (APT) is collaborating with JSTOR to digitize, preserve

and extend access to APT Bulletin.

htt // j t

http://www.jstor.org/action/showPublisher?publisherCode=aptech

http://www.jstor.org/stable/40284498?origin=JSTOR-pdf

http://www.jstor.org/page/info/about/policies/terms.jsp


http://www.jstor.org/stable/40284498?origin=JSTOR-pdf

http://www.jstor.org/action/showPublisher?publisherCode=aptech



Towards N e w E r a o f Cultural-Heritage

Recording a n d Documentation

ROBERT WARDEN

A decade of technological innovation

has created a new culture in

recording and documenting cultural

heritage.

The Industrial Revolution set the con-

text for the creation of the modern

mindset, a cultural outlook framed bymachines. From the kitchen to the

airport, the use of machines was

adopted with promises of freedom from

labor and greater social equality.1 To

question their efficacy seems ludicrous

in light of their manifest pragmatic

power of economy and utility and

despite cogent arguments for a higherquality of life without them.

The modern mindset was fertile

ground for similar promises of freedom

from labor offered by the digital revolu-

tion in the second half of the twentieth

century. Computing in all its forms so

permeates our lives and empowers

society in ways unimaginable 40 years

ago that it is difficult to imagine life

without it. In most industrialized na-

tions digital life is a given.The wave of technology that emerged

in the 1980s was but a swell in compari-son with new

developmentsover the

past ten years, and no end is in sight.

Fig. 1 Laser scan of B. B. GoodrichHouse, Anderson, Texas, 1999. The scan was performed by Cyra

Technologies, Inc.,to complement a recording project utilizingdigital photogrammetry.The housewas recordedfor HABS n 1994 by Texas A&MUniversity.Allimages courtesy of the author.

These innovations found application in

nearly every discipline, and historic

preservation was no exception. Software

developments in structural and material

analysis, graphic information systems

(GIS), and building information systems

(BIM) are just three examples of soft-

ware technologies adapted by preserva-tion engineers and architects. Hardware

developments like ground-penetrating

radar, resistivity tomography, and syn-chrotron radiation have given engineers,

conservators, and historians new analyt-ical tools. This paper focuses on devel-

opments in technologies employed in

preservation research and practice-

those most relevant to the recording and

documentation of cultural heritage.Even such a tight focus necessitates onlya cursory discussion of certain technolo-

gies, relegating others to simply be

mentioned.

The late twentieth-century explosionof digital innovations has created as

much interest in the machine as its

product; the endless debates over the

best computers, plotters, software, mp3

players, or cell phones are examples.

Granted, similar debates over technol-

ogy have occurred in the past, but a

greater choice of technological tools

seems to garner a greater percentage of

our attention than ever before. Within

the narrow focus of documentation and

recording of historic buildings and sites,a fascination with tools has never been

greater. New tools for recording infor-

mation about buildings have extended

the meaning of documentation. GIS

tools for facility managers and city

planners are adapted to record historic-

building information. Survey tools such

as total stations and GPS, originallyused in civil engineering or the oil and

gas industries, are now commonplace in

the employment for historic preserva-tion. Aerial tools like photogrammetry

5

This content downloaded from 168.176.162.35 on Mon, 15 Apr 2013 00:34:16 AMAll use subject to JSTOR Terms and Conditions






6 APT BULLETIN: JOURNAL OF PRESERVATION TECHNOLOGY / 40:3-4, 2009

Fig. 2. Recording the cliff face by total station at

Montezuma Castle in Arizona in 2002.

andLIDAR, ong employedfor defense

purposesandatmospheric ciences,have

beentechnologicallyadapted o solveevermorechallengingproblems n pres-ervation.2Similarly, ocumentationhasbeenpushedfrom2D to 3D, thoughfor

verysoundreasonsof archival tability,2D drawingsremain he desired inal

product.This conditionhas createdatensionbetweenthe 3D recording oolsand the final2D product.That tensionhas resulted n software nnovations ike

Polyworks,Kubit PointCloud,GexcelJRCReconstructor, ndmanymore,

regardless f the fact that theirlifespanmaybe ultimately imited.Suchrapiddevelopmentdivertsour attentionfrom,butnot our desirefor,the assurance hatourculturalheritageremainsvital.

Remembering the Recent Past

Thoughthere were still holdouts formoretraditional ools like pencils,pens,paper,and draftingequipmentoverthe

pastdecade,most universityprograms

andprofessionalofficeswereoperatingcomfortably n some formof computer-aideddesign(CAD)by 1999.3The

ambientaroma of ammoniaandthe

cloggingof technicalpens in pen plot-terswas lost but not forgotten.Ink-jet

plottersandprinterswerecommon,andthe use of large-format lectrostatic

plotterswas declining.Windows98 wasa yearold, and the PentiumIIIchipwasaboutto be born,justtwo yearsafter its

sibling,the PentiumII. AutoCad version14 was justtwo yearsold, and Micro-stationwas on versionJ (version7) ofits 32-bit system.A nice $3,000 com-

putersystemwould include a PentiumIII

processor,128 MB

RAM,15GB

harddrive,DVD, CDRW,zip drive,anda 19-inch monitor.Bycontrast,todayan Intel Coreduo machinewith 4 GB of

RAM, 500 GB harddrive,150 gigabyteexternalharddrive,a DVD writer,and19-inchflat-panelscreenwould costaround$2,000, about half the cost ofthe previousmachine n today'sdollars.4

Innovations n digitaltechnologyleadingto morerobustcomputersalsocreatedmorerobust hardwareandsoftwaretechnologies or recordingand

documenting ulturalheritage.Not

surprisingly,he major developmentswerein 3D tools for both recordinganddocumentation.Totalstations and

photogrammetricools had long enjoyeduse in otherdisciplinesbut were nowmadeeconomically easiblefor cultural-

heritageuse.Terrestrialaserscanningwas burstingon the scenein 1999 for

heritageuse,makingpossibledetailedremote measurement f veryfragilestructures, uchas the 1850 B. B. Good-richHouse in Anderson,Texas(Fig.1),or complexheritageobjects,suchas theStatueof Liberty.5

Scaleandirregular r organicformsare two conditionsthatpresentparticu-larlydifficult, houghnot impossible,problems or traditionalmethodsofhand measurement.Both conditionsareoften foundin historicbuildings, uchas

very largebuildings ikecathedralsor

government omplexes,statecapitols,or

countycourthousesor very organicvernacular tructures,ike cliffdwellingsor archaeological uins.New technologyhas beenespeciallyhelpful regardingthesetypologies.Inthe 1980s CADallowed for very large buildings,evenif

measuredby traditionalmethods,to berepresentedn the computerat full scalewith full detail.Inthe 1990s with more

offerings n surveyhardware,arge-scalebuildingscould be measuredby pho-togrammetry r total stations. Later

developmentsn reflectorless otal sta-

tions, terrestrialaserscanners,and

close-rangephotogrammetry ided

large-scaleprojectsby enablingremote

recordingof building nformation.These

tools not only savedtimein the fieldbutincreased afety by not requiring argetplacement n dangerousocations.

What was good for scale was also

good for organic orms.Traditional

recordinganddocumentation eliedon

datum ines,usuallyplacedat known

anglesto gatherand drawbuildinggeometry.Thegreater he irregularity fthe building, he more care one neededin measuring nddrawing o ensure

accuracy.The tools developed ince thelate 1990s measured oordinatevaluesof particularpointsinsteadof geometryand its dimensionand orientation.This

changeallows morefreedom n estab-

lishingpointsof reference, inceeachreferencepoint is automatically efer-enced to an established oordinate

system.

Total stations. Total stationsare sur-

veyinginstrumentsusedin the field todetermine he locationof a pointofinterestby knowingthe angleanddistanceof that pointwith respect othe instrument ocation.Theyare exten-sions of transitsandtheodolites,angle-measuring nstruments,with the addi-tionalcapabilityof measuringdistances.Total stations recordcoordinateposi-tions for pointsof interestandwere firstavailable n 1998 as reflectorlessnstru-

ments,negating he need to positiona

reflectiveprismor targetat the point ofinterest.Architectural lements hatwere too fragile,unsafe,or unreachablecould be measuredremotely.Prices orthese tools were anywhere rom

$20,000 to $40,000 in 1999. Pointstakenwith a total stationaretypicallycoded and linked to a sketchor photo-graph.Theycould be usedto mark

significantpointson the object,tocontrol traditionalmethods ikehandmeasurements nd drawings,or tocontrol measurementsakenwith otherremotesensingtools, like photogram-

metry (Figs.2 and

3).Photogrammetry.Photogrammetry,processof achievingmeasurementsfromphotographs,has a historyas longas that of photography.Terrestrial

photogrammetrywas developed irst nthe late nineteenthcentury,but its

advantagesas an aerialtool for map-pingwererealized n 1913 afterman'sfirstflightin 1903.6Analogstereo

photogrammetrywas invented n the







CULTURAL-HERITAGE RECORDING AND DOCUMENTATION 7

Fig. 3. Tying datum points on the terrace at

Montezuma Castle with points established on

the ground, 2002. This procedure allowed hand

measurements to be registered together in 3D.

late nineteenthcenturyandcontinuedto develop throughthe twentiethcen-

tury,untilthe adventof digitalcomput-ers and imaging.By 1999 photogram-metryand new algorithmswere

developedfor a processcalledconver-

gent photogrammetry,which couldcalculatecamerapositionsautomati-

cally frommultiple mages.Theseim-

agesand calculatedcamerapositions

couldthen be usedto determinecoordi-natepointsof interest n the photo-graph.Digital imageswere achieved

primarilyby scanningfilm, becauseoff-the-shelfdigitalcamerasproducedimagesthat were only about2 megapix-els, not nearlydenseenoughfor finemeasurement.The softwareallowedmorefreedom n taking photographsimagesdid not needto be stereoscopicpairs- makingfield work easierandfaster.The promiseof this technologywas that adequateaccuracies n 3D

modelingcould be achievedby con-

sumer-gradeameras, herebyopeningup the processto more industriesandsmalleroffices.Extremelyaccuratemodels still required xpensiveequip-ment at all stages:metriccamera,film

scanner,and software.Softwarechoicesbloomedduringthis time, with offer-

ings from$500 to $25,000. Projectsofall scalesthatrequiredremotesensingweregood candidates or this method

(Fig.4).

Laserscanning. AerialLIDAR(LightDetectionAnd Ranging),or laser scan-

ning, technologyhad beenin use byvariousindustries incethe late 1970s,but by 1997 the technologywas trans-

formedfor terrestrialuses and hadalreadybeenemployed n heritageprojects.7LIDARscannersemit thou-sandsof beamsof lightpersecond andrecordthe relativeangle,distance,andlocation of eachpoint reflectedback tothe instrument.The result s a cloud of

points that represent he spatialorgani-zation of the objector objectsfromwhich theywere reflected Fig.5). Atthis time therewere few companiesmanufacturingerrestrial canners,and

pricesrangedfrom $100,000 to

$200,000.

Cultural Change

Changes o the cultureof historic-

buildingdocumentation hat took solidroot in the late 1990s have becomenormative.Technological nnovationshavechangedthe expectationsfor final

products n heritagedocumentationandthe processesone engagesto meetthose

expectations.Althoughthe idea of

engagingthe practiceof documentingahistoricbuildingwith pencil, paper,string,and level is appealing,youngpractitionersarecomfortablewith

digitaland 3D tools. Turningback theclock for studentsby teachinghand-documentation echniques s a valuable

pedagogicalexercise,but requirementsof professionalpracticeoften necessitateefficientmergingof staff talentwithavailable ools. The workforcehas

changedand is comfortablewith cur-renttechnology.

The word draw connotesa pullingor

extractingof something(onedraws

blinds,water,blood, conclusions,etc.).

Drawinghistoricbuildings s an act of

extracting mportant nformation rom

the realobjectanddisplaying t in adifferentway.Traditionally, drawingwas a 2D presentationof this extractedinformation.By 1999, with laser scan-

ningandclose-rangedigitalphotogram-metry,drawingas a 2D interpretationwas challengedby 3D modelingas thenormativeproduct.The logic was sim-

ple:since the measuring ools - total

stations,photogrammetry,nd laserscanners operated n 3D space,the

3D modelshould be the normative

product; f 2D drawingswererequired,theyshould be extracted rom themodel.Withthis mindsetnumeroussoftwareofferingsdevelopedwiththe

goal of operatingprimarilyn 3D withthe promiseof secondaryproducts n2D.

Onlineactivity usta decadeago waswell underwaybut dullby today'sstan-dards.The residential nternet onnec-tion was largelya dial-upserviceover

phonelines,andservicewas not ubiqui-tous. Muchof the world cannow beconnectedas often as we wish,whereverwe wish. The cultureof the team officeor studioso prevalentn previousdecadeshas becomemore flexible.Teamsworkingon a largeprojectcancollaborate romremote ocations,

sharingdigitalmeasurements, hoto-graphs,andpointclouds,as well as

digitalcopiesof traditional ketches.

Consequently,oftware s no longerpurely ndependentbut offerstransla-tions of filetypesto a wide varietyofothertypes.Ironically,n a culturewheregeographicsolation s more

possible,sharinghasemergedas a cul-turalgoal. Where ools of the pastne-cessitated haringby being ocated n thesameplace,contemporaryechnologyallows for sharing o occurremotely.

Contemporary eritage-documenta-tion projectshaveretained oregoalscommonto projectsa decadeor two

ago (conservation f designand con-structionknowledge,conservationofmaterialand aestheticheritage,promul-gationof culturalawareness),but con-

temporaryprocessesdiffergreatly.Ten

yearsafterthe Pentium II, aptopscanwithstanddrivingrain and fallsontoconcreteandhavemanyGBsof RAMand a TBof hard-drive pace.Bluetoothwirelessconnectivityhasreplaced a-

bles,anddigital mageseasily range nthe 10- to 20-megapixelresolution.

Tools haveevolved to becomesleeker,faster,moreaccurate,andmorepower-ful. Although he datagathered s

largely n the sameform as a decade

ago, more can be done with it in postprocessing n the officeor studio. Soft-wareofferings or workingwith pointcloudsareplentiful,ranging n priceand

processfrominexpensiveandsimple o

expensiveandcomplex.Total stationsoffer reflectorless angesof almosta







8 APT BULLETIN: JOURNAL OF PRESERVATION TECHNOLOGY / 40:3-4, 2009

Fig. 4. Pueblitos of Dinetah, Bolder Fortress Pueblito, New Mexico, 1997.

Due to its position and irregular form combinations of total station and

convergent photogrammetry were used for recording.

Fig. 5. As part of the analytical work on the cliffs at Pointe du Hoc Battle-

field in Normandy, France, in 2008, point clouds like this were generatedfrom a Riegl Z390 laser scanner.

kilometer, while new scanners have

surpassed that distance and now record

hundreds of thousands of points persecond. Technology at this point is

outpacing methodology and challengingacademic and professional practice to

keep up.

Methods

Objectivity is the benchmark of all

approaches to documentation. Unless

time and money concerns are prohibi-

tive, assumptions about properties like

perpendicularity and likeness should

not be made. The traditional method

for obtaining objectivity was the datum

line. Often a datum box would be con-

structed with right angles such that it

encased the object or building. Right

angles simplified the drafting task,further ensuring the objectivity of the

datum lines making up the box. Todaythe total station is the normative tool to

ensure objectivity. Datum lines are still

quite useful, but they need not bear any

particular relationship with each other,

since CAD drafting can easily utilizecoordinate values to locate points. The

coordinate output of total stations fuses

with coordinate input systems in CAD.

At Montezuma Castle in Arizona in

2002, for example, datum lines were

established for triangulating wall loca-

tions (Fig. 6). The rooms were small, so

only one line was needed for takingmeasurements. These lines were estab-

lished for all 20 rooms on five different

levels by the total station, so that teams

could simultaneously hand measure the

location of important points in each

room by trilateration, utilizing points on

the datum line. Each team, operatingwith either a tape measure or a laser

distance meter, measured distances from

multiple points on the datum line to a

single point on the wall. The intersection

of these distances from their respective

points in CAD determines the CAD

representation of the wall point. A ro-

tatinglaser level was used to maintain a

consistent plan cut level from which to

make measurements.

Datum lines or points are also impor-tant for producing sections and eleva-

tions, especially when many measure-

ments must be made remotely with a

total station or through photogramme-

try. Datum points are not strictly re-

quired for these 2D drawings, since theyare typically presented separately from

the 2D plans. However, it is quite useful

to be able to relate their measurements

to plans and site plans, so having a com-

mon-coordinate system is very valuable.

This can be accomplished through setup

points in the field or through registra-tion points that later can be used to

orient the measurements later in the

computer.When stationed at known datum

points, total stations can be used to

deliver section and elevation informa-

tion in relation to each other and to

other building and site elements. These

points may be taken from within soft-

ware on the total station and down-

loaded later to a computer, or they maybe downloaded immediately to a data

collector. Data collectors are handheld

computers that run a variety of surveysoftware suitable for engineering and

architectural work. Points are typicallycoded and visible on the screen as a

CAD drawing. These points may be

connected by lines and downloaded to a

computer as drawings or as a set of

points to be connected later. One mayalso eliminate the data collector

bycommunicating directly with the total

station through software running within

a CAD program on a laptop. The con-

nection can be made through a wireless

Bluetooth connection to reduce the

clutter of wires and allow for greater

flexibility in the field. In this configura-tion the total station becomes essentiallya 3D pencil; when, for example, a line

command is given on the computer and

when the total station is positioned on

the desired point, a signal is sent to the

total station to input the coordinates of

the first point of the line. As the total

station continues to subsequent points,these coordinates are queried by the

computer. The result is an instantaneous

CAD drawing, enabling errors to be

spotted in the field. Most software of

this type has commands for creating

clean, fast, and accurate drawings in the

field.

The geometric point has long been

the foundation of documentation strat-

egy. Points are terminations for line







CULTURAL-HERITAGE RECORDING AND DOCUMENTATION 9

Fig. 6. Montezuma Castle Level 3 floor plan created by a combination of hand measurement, total

station, and convergent photogrammetry, 2003.

segments that represent material and

dimensional information drawn from

buildings. Traditional 2D drawingsutilize the line segment and linear di-

mension as their primary elements. The

point, as foundational as it was to the

creation of linear dimension, was sec-

ondary to that dimension. Point posi-tions in traditional drawings were al-

ways relative to building elements andother important dimensions. Technologyhas reversed the relationship between

dimension and point. Total stations,with their ability to relate positions

through a common-coordinate system,favor the absolute position of the pointinstead of the dimension. The dimension

becomes secondary and known onlyafter point information is queried on the

computer. This change in data hierarchyshifts concern in the field for objectdimension to concern for point accuracyand geometric tightness. It also creates a

not-so-subtle shift of attention from the

object being measured to the measuringtool.

Early concerns over the detrimental

effects of CAD on architectural thinkinghave not disappeared - largely because

the prognosticators of those concerns

are still active - but they have largelyabated in the context of myriad advan-

tages offered by these tools. The culture

of technological acceptance in the late

1990s has developed into a culture of

technological complacency. New tech-

nologies are still exciting, but they are

greeted with less a feeling of wonder-

ment and more one of expectation.Terrestrial laser scanners have become,over the last ten years, the tool du jourin heritage documentation, despite their

price, which is still extremely high.

Ironically they have softened the focuson the point created by total stations

and shifted it to a focus on the pointcloud. Points within a point cloud cre-

ated by a laser scanner are indiscrimi-

nate compared to points created by total

stations, in that they are not chosen and

coded as important points on the objectof interest by the operator as they are

with total stations. Laser scanners no

longer give importance to individual

points, but much like the camera in

relation to the sketch, they refocus at-

tention from point to image. However,unlike the

image,the

pointcloud con-

tains coordinate information for each

point and can be queried directly for

dimensional information between anytwo points.

Point clouds hold tremendous advan-

tages over traditional documentation

methods and total-station surveys.Individual points may not representknown important points on the object,but groups of points are recognized as

important objects, such as doors, win-

dows, or trees, very much the same way

objects in photographs are treated. Point

clouds are used in many ways with

different software. Some software, such

as GexelReconstructor, Polyworks,

or

Kubit PointCloud, manipulate the pointcloud to create 3D views or walk-

throughs, plans, sections, and elevations.

Reconstructor and Polyworks will also

create textured surface models that

allow for creating land contours, high-resolution sections, elevations, and 3D

views. Point clouds offer opportunitiesfor many creative options in presenta-tion and analysis, giving a greater free-

dom to alter decisions for specific proj-ect requirements.

There are some disadvantages to

laser scanners, but the greatest is their

price. Prices have dropped over that last

10 years, but at about $100,000, theyare largely out of range of most profes-

sional, academic, and government of-

fices. An alternative path to point-cloud

production has emerged with advances

in digital close-range photogrammetry,which utilizes calibrated metric or non-

metric cameras to create points from

automated matching between two pho-

tographs. The resulting points can then

be processed and queried like pointclouds generated from 3D scanners. The

advantage of this system is that the

cameras used are less expensive than

point-cloud scanners and much lighterand easier to operate. They, too, have

some disadvantages, especially with

respect to computing time required to

generate dense point clouds and variable

accuracies depending on camera type,

lighting conditions, and scale of object.All of these issues can be controlled

through skilled use of cameras.

David 3D Scanner software creates

scans from webcams and construction-

grade line lasers. Other software, such

as Strata Photo 3D, creates 3D textured

models automatically in a few minutesfrom about 20 photographs. These

examples are priced in the range of $500

to $1,000 instead of tens or hundreds of

thousands of dollars. While they will not

be an answer for every problem in con-

servation, they give promise that techno-

logical development relevant to heritage

recording and documentation is far from

over.







10 APT BULLETIN:JOURNAL OF PRESERVATIONTECHNOLOGY 40:3-4, 2009

Conclusions

Documentation of cultural heritage over

the last ten years has been dominated

by development of digital tools. Com-

puters are faster and lighter; digital

cameras have greater light-gatheringcapabilities and ever-increasing memoryand resolution capabilities; total sta-

tions are wireless and reflectorless; and

laser scanners now measure hundreds of

thousands, rather than tens of thou-

sands, of points per second. New tech-

nologies are emerging for smaller ob-

jects, such as artifacts found in archae-

ology.Whereas practitioners in the previous

decade were introduced to new digital

tools, contemporary practitioners antici-

pate developments within that basic tool

set. As computing power and manufac-turing tolerances are tightly controlled,more tools will be generated for drawinginformation from our heritage objects,and there will be faster and more accu-

rate processing of that information. But

the proliferation of tools, as wonderful

as they are, can have unintended conse-

quences for our heritage-documentationefforts. The efforts required to keepabreast of the latest techniques or up-dated with changes in the latest version

of software or hardwareindirectlyincrease the cost of documentation.

Expense for time and materials in keep-

ing current diverts attention from efforts

directly related to the heritage of inter-

est. As our focus is shifted from our

heritage to our tools, we can become

separated from our heritage, and our

understanding of it can become diluted.

As we anticipate the next round of

technology, we should be mindful that it

is our concern for cultural heritage and

its documentation that should drive our

embrace of new tools and not the tools

themselves.

ROBERTWARDEN has an academic back-

ground in electricalengineering,architecture,and philosophy. He joined the architecture

faculty at Texas A&M Universityin 1994 after

practice in Philadelphiaand became directorofthe Center for Heritage Conservation in 2007.He has been recordingnational and interna-tional cultural heritagesites since 1986.

Notes

1. ReynerBanham,Theoryand Design in theFirstMachineAge (Cambridge,Mass.: MIT

Press, 1960, repr.1983), 9.

2. Raymond Measures, LaserRemote Sensing:Fundamentalsand Applications (New York:

John Wiley and Sons, 1984), 320-362.

3. E. BlaineCliver,John A. Burns,Paul D.

Dolinsky, and EricDelony, "HABS/HAERatthe Millennium:AdvancingArchitecturaland

EngineeringDocumentation,"APT Bulletin29,no. 3-4 (1998): 34.

4. See www.measuringworth.com/uscompare/.

5. Point cloud of the B. B. Goodrich House, in

Anderson,Texas, scannedwith a Cyrax 250 in1999. John A. Burns,éd., RecordingHistoric

Structures,2nd éd. (Hoboken, N.J.:John Wileyand Sons, 2003), 241.

6. Robert Burtch,"Historyof Photogramme-try,"2004 course notes, The Centerfor Pho-

togrammetricTraining,FerrisStateUniversity,

http://www.pharmacy.ferris.edu/faculty/burtchr/sure340/notes/history.pdf.

7. G. Fangi, C. Nardinocchi, "ExperiencesofLaserAutoscanning for Architecture:TheDomus Aurea in Rome and the San Giovanni's

Baptistryin Florence,"in Proceedingsfor CIPAInternationalSymposium 1999, http://cipa.icomos.org/fileadmin/papers/olinda/99c606.pdf.





towards a new era of cultural heritage

Documents