Scope of Remote Sensing Scope of Remote Sensing

in Earth Sciencein Earth Science

The collection and The collection and

interpretation of interpretation of

information about an information about an

object without physical object without physical

contact with the object; contact with the object;

eg, satellite imaging, eg, satellite imaging,

aerial photography, aerial photography,

and open path and open path

measurements.measurements.

Satellite remote Satellite remote

sensing has sensing has

become a common become a common

tool to investigate tool to investigate

the different fields the different fields

of Earth and of Earth and

environmental environmental

sciences. sciences.

GEOLOGYGEOLOGY

Remote sensing is Remote sensing is used as a tool to used as a tool to extract information extract information about the land surface about the land surface structure, composition structure, composition or subsurface, but is or subsurface, but is often combined with often combined with other data sources other data sources providing providing complementary complementary measurements. measurements.

Remote sensing is not Remote sensing is not

limited to direct geology limited to direct geology

applications applications -- it is also it is also

used to support logistics, used to support logistics,

such as route planning for such as route planning for

access into a mining area, access into a mining area,

reclamation monitoring, reclamation monitoring,

and generating basemaps and generating basemaps

upon which geological upon which geological

data can be referenced or data can be referenced or

superimposed.superimposed.

Geological applications of remote sensing include the Geological applications of remote sensing include the following:following:

surficial deposit / bedrock mapping surficial deposit / bedrock mapping

lithological mapping lithological mapping

structural mapping structural mapping

sand and gravel (aggregate) exploration/ exploitation sand and gravel (aggregate) exploration/ exploitation

mineral exploration mineral exploration

hydrocarbon exploration hydrocarbon exploration

environmental geology environmental geology

geobotany geobotany

baseline infrastructure baseline infrastructure

sedimentation mapping and monitoring sedimentation mapping and monitoring

event mapping and monitoring event mapping and monitoring

geogeo--hazard mapping and planetary mapping hazard mapping and planetary mapping

Geoenvironmental Geoenvironmental

research can help to research can help to

identify the causes of identify the causes of

these events, point these events, point

the way to the way to

rehabilitation rehabilitation

measures, and lend measures, and lend

support for early support for early

warning systems warning systems

Remote sensing Remote sensing

adds considerably adds considerably

to this research by to this research by

providing a wide providing a wide

variety of sensors variety of sensors

operated from operated from

airborne and airborne and

satellite platforms. satellite platforms.

The GARS Program The GARS Program

of UNESCO and of UNESCO and

IUGS provides a IUGS provides a

means of continually means of continually

investigating the investigating the

geological geological

applicability of applicability of

remoteremote--sensing sensing

techniques. techniques.

The multispectral The multispectral

scanner images scanner images

from the first nonfrom the first non--

meteorological, meteorological,

civilian Earth civilian Earth

observation observation

satellites, the US satellites, the US

LANDSAT series LANDSAT series

launched in 1972 launched in 1972

The LANDSAT The LANDSAT images were images were received received enthusiastically by enthusiastically by a small scientific a small scientific community, mostly community, mostly geologists, geologists, oceanographers oceanographers and geographers. and geographers.

The GARS Program, The GARS Program, jointly sponsored by jointly sponsored by UNESCO and IUGS, UNESCO and IUGS, was inaugurated in was inaugurated in 1984 (Weber, 1985) 1984 (Weber, 1985) LANDSATLANDSAT--1,and 1,and LANDSATLANDSAT--4, containing 4, containing Thematic Mapper, was Thematic Mapper, was launched, adding an launched, adding an additional three bands additional three bands in the SWIR (shortin the SWIR (short--wave infrared) to the wave infrared) to the existing visible (VIS) existing visible (VIS) and nearand near--infrared (NIR) infrared (NIR) bands. bands.

Remote sensing has Remote sensing has

become a widely become a widely

accepted research accepted research

tool by almost all tool by almost all

Geological Surveys Geological Surveys

the world over.the world over.

Why remote Why remote

sensing?sensing?

A synoptic view of A synoptic view of

regional scale is a regional scale is a

much different much different

perspective than perspective than

point ground point ground

observations observations

when trying to when trying to

map structural map structural

elementselements. .

Remote sensing Remote sensing offers this offers this perspective and perspective and allows a geologist to allows a geologist to examine other examine other reference ancillary reference ancillary data simultaneously data simultaneously and synergistically, and synergistically, such as geosuch as geo--magnetic magnetic information.information.

Remote sensing gives the overview Remote sensing gives the overview

required to required to

1.Construct regional unit maps, useful for 1.Construct regional unit maps, useful for

small scale analyses, and planning field small scale analyses, and planning field

traverses to sample and verify various traverses to sample and verify various

units for detailed mapping; units for detailed mapping;

2.Understand the spatial distribution and 2.Understand the spatial distribution and

surface relationships between the units. surface relationships between the units.

Remote sensing offers Remote sensing offers

this perspective and this perspective and

allows a geologist to allows a geologist to

examine other examine other

reference ancillary reference ancillary

data simultaneously data simultaneously

and synergistically, and synergistically,

such as geosuch as geo--magnetic magnetic

information.information.

Geologic Unit MappingGeologic Unit Mapping

Mapping geologic Mapping geologic

units consists units consists

primarily of primarily of

identifying identifying

physiographic units physiographic units

and determining the and determining the

rock lithology or rock lithology or

coarse stratigraphy coarse stratigraphy

of exposed units. of exposed units.

Data requirementsData requirements

Two different scales of mapping require slightly Two different scales of mapping require slightly different imaging sources and parameters:different imaging sources and parameters:

1. For site specific analysis, airphotos provide a 1. For site specific analysis, airphotos provide a high resolution product that can provide high resolution product that can provide information on differential weathering, tone, and information on differential weathering, tone, and microdrainage. Photos may be easily viewed in microdrainage. Photos may be easily viewed in stereo to assess relief characteristics. stereo to assess relief characteristics.

2. Regional overviews require large coverage area 2. Regional overviews require large coverage area and moderate resolution. An excellent data and moderate resolution. An excellent data source for regional applications is a synergistic source for regional applications is a synergistic combination of radar and optical images to combination of radar and optical images to highlight terrain and textural information. highlight terrain and textural information.

Today, with each new satellite in space, Today, with each new satellite in space,

some of the previous work has to be some of the previous work has to be

repeated in order to test the new repeated in order to test the new

technologies. This has led to a wider technologies. This has led to a wider

acceptance of remote sensing for acceptance of remote sensing for

geological applications and it has found its geological applications and it has found its

place among the disciplines of the earth place among the disciplines of the earth

sciences. sciences.

Interpretation of the pictureInterpretation of the picture

The Navajo Sandstone The Navajo Sandstone

((aa) is the brightest single unit in the scene, followed by the valley floor to the ) is the brightest single unit in the scene, followed by the valley floor to the east, much of which is covered by alluvium east, much of which is covered by alluvium

((bb). The Entrada ). The Entrada

((cc) and Wingate ) and Wingate

((dd) Sandstones are notably darker, as is the top surfaces of the Mesaverde ) Sandstones are notably darker, as is the top surfaces of the Mesaverde

((ee). Note that the Wingate "pinches" out along the Fold towards the bottom of ). Note that the Wingate "pinches" out along the Fold towards the bottom of the image, which suggests that its dip steepens making its outcrop pattern the image, which suggests that its dip steepens making its outcrop pattern thinner. The Kayenta Formation thinner. The Kayenta Formation

((ff) is barely discernible in the image as a thin, darker tone, but the Chinle ) is barely discernible in the image as a thin, darker tone, but the Chinle

((gg), also darker, has a wider outcrop pattern, because it is thicker and less ), also darker, has a wider outcrop pattern, because it is thicker and less steeply dipping. The Emery Sandstone steeply dipping. The Emery Sandstone

((hh) has a darker tone than the overlying Masuk Shale ) has a darker tone than the overlying Masuk Shale

((ii) because, in the field, it is dark brown (similar to the Dakota Sandstone seen ) because, in the field, it is dark brown (similar to the Dakota Sandstone seen in the foreground of this picture from the ground).in the foreground of this picture from the ground).

These dark These dark

features are features are

outspillings of salt outspillings of salt

that have been that have been

called "salt called "salt

glaciers". glaciers".

Atlas Mountain system of Atlas Mountain system of northwest Africa northwest Africa

Atlas Mountain system of Atlas Mountain system of

northwest Africa northwest Africa

The white sinuous band against a fold ridge The white sinuous band against a fold ridge

is a dry stream or wadi.is a dry stream or wadi.

These are the highest mountains in Africa and resemble parts of the These are the highest mountains in Africa and resemble parts of the

Alps except that the vegetation is distinctly different.Alps except that the vegetation is distinctly different.

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