It is defined as the science of:
Acquiring images refers to the technology employed eg
electro-optical scanning system.
Processing refers to the procedures that convert raw
data into images.
Interpreting converts an image information that is useful
for human use
cont…
Remote Sensors are mechanical
devices where informations are stored
or recorded about the object or scene
under study.
They are classified as
Active or Passive
Image or Non-Image forming
Commercial or Military
Passive Remote Sensing:
If the observation is made based on the
electromagnetic radiation from the sun or self-
emitted radiance.
E.g. Photography during daytime with the help of
Sunlight.
Active Remote Sensing:
It is also possible to produce electromagnetic
radiation of a specific wavelength or band of
wavelength to illuminate the object or terrain. The
interaction of this radiation can then be studied by
sensing the scattered radiance from the target.
E.g. Photography at night with the help of Flash
Light.
“The vehicle or carrier for remote sensor
is borne is called the Platform.”
The typical platforms are satellite and
aircraft, but they can also include radio
controlled airplanes, balloons, and kites for low
altitude remote sensing, as well as ladder and
cherry pickers for ground investigation.
Air borne plat form
Space borne plat form
Ground borne plat form
(Cherry-picker with passive microwave
radiometer)
The basic principle of remote sensing is governed
by 2 processes viz.
Data acquisition and Data analysis.
It comprises of the following distinct elements:
a). Energy source.
b). Propagation of energy through the
atmosphere.
c). Energy interaction with the Earth’s surface
feature.
d). Air borne/Space borne sensors to record the
reflected energy.
e). Generation of sensor data in the form of
pictures or digital information.
It involves examining the data using various
viewing instruments to analyse pictorial data or a
computer to analyse digital sensor data.
Reference data or Ground truth check is an
essential part of data analysis.
The acquisition of reference data involves
collection of information about objects, area or any
phenomena that are remotely being sensed.
Finally the information is presented to users who
apply it to their decision making process.
A. Radiation and the
atmosphere
B. Interaction with target
C. Energy recorded and converted by
sensor
D.Reception and
processing
E.Interpretation and
analysis
A
A
B
D
E
C
12
65
28
33
76
Process of Remote Sensing
The Electromagnetic Spectrum ranges from the shorter
wavelengths (including gamma and x-rays) to the longer
wavelengths (including microwaves and broadcast radio
waves). There are several regions of the electromagnetic
spectrum which are useful for remote sensing.
The light which our eyes can detect is part of the visible
spectrum (small)
There is a lot of radiation around us which is "invisible" to our
eyes, but can be detected by other remote sensing
instruments and used to our advantage
The visible wavelengths cover a range from approximately 0.4
to 0.7 micro meter (violet to red)
There are four forms of interaction that can take place
when energy strikes, or is incident upon the surface:
•Transmission (T): radiation passes through a target
•Reflection (R): radiation "bounces" off the target and is
redirected
•Scattering (S): scattering occurs when incident
electromagnetic radiation is dispersed in all
directions from a rough surface.
•Absorption (A): radiation is absorbed into the target
The proportions of each interaction will depend on
the wavelength of the energy and the material and
condition of the feature.
Geology involves the study of landforms, strucures,
and the sub surface to understand the processes
operating in the earths crust.
Geological studies are not limited only to the earth-
remote sensing has been used to examine the
composition and structure of other planets.
Remote sensing is used as a tool to extract
information about the land surface , composition
or sub-surface.
Multi-spectral data can provide information on
lithology or rock composition based on spectral
reflectance.
Radar provides an expression of surface
topography and roughness.
It is not limited only to direct geological
applications but it is also used to support
logistics,such a route planning for access into
mining area,reclaimation monitoring and
generating base maps upon which geological
data can be referenced or superimposed.
Mapping of surficial deposit/bedrock.
Lithological mapping.
Structural mapping.
Lineament extraction.
Mineral exploration.
Exploration of hydrocarbon.
Environmental geology.
Geobotany.
Mapping and monitoring.
Geohazard mapping.
Planetary mapping.
Structural geology plays an important role in mineral
and hydrocarbon exploration and potential hazard
identification and monitoring.
Structural mapping is the identification and
characterization of structural expressions.
Structures can indicate potential location for oil and gas
reserve and provide clues to potential hazards such as
earthquakes landslides and volcanic activities.
Aerial photos can be used in temperate areas where
large scale imagery is used, particularly to map
potential geohazards.
Geological Unit Mapping consists primarily identifying
physiographic units and determining the rock lithology
or coarse stratigraphy of exposed units.
Remote sensing can be used to describe the lithology
by the color, weathering and erosion characteristics,
drainage patterns and thickness of bedding.
Unit Mapping is useful in oil and mineral exploration
since this resource are often associated with specific
lithologies.
Regional lineaments and structural trends
along which groups of mining districts may
occur.
Mapping local fracture patterns that may
control individual ore deposits.
Detecting hydrothermally altered rocks
associated with ore deposits.
Providing basic geologic data.
It deals with different landforms that characterize the
earth’s topography, origin, sequence of evolution,
present status and their future trend.
Until space age, scientists conducted most geomorphic
analysis by mapping (generally topographic and
geologic) and by field observation and measurements.
Eventually, aerial photographs became a prime tool for
mapping and interpreting.
Modern macro-geomorphology makes extensive use of
global observation from space crafts that employs a
variety of imaging and sensing systems. Eg: Vidicon
imaging, multi spectral scanning, radiometers and
Radars.
Hydrology is inherently related to many other
applications of remote sensing, particularly forestry,
agriculture and land cover.
Most hydrological processes are dynamic and require
frequent observation.
Remote Sensing offers a synoptic view of the spatial
distribution and dynamics of hydrological phenomena,
often unattainable by traditional ground surveys
Examples of Hydrological applications:
Flood delineation and mapping
Remote sensing techniques are used to measure and
monitor the real extent of the flooded areas to
efficiently target rescue efforts and to provide
quantifiable estimates of the amount of land affected.
Incorporating remotely sensed data into a GIS allows
for quick calculation and assessment of water levels,
damage, and areas facing potential flood danger
Remote Sensing based groundwater prospect zone
map serve as a base for further exploration using
hydrogeological and geophysical methods to locate
well sites.
If remote sensing data are used at first level to
delineate prospective zones and further follow up by
hydrogeological and geophysical surveys, higher
success could be achieved besides saving in terms of
cost, time and work.
Remote Sensing data helps in identifying suitable areas
for recharging groundwater.
Remote Sensing means acquiring information
about an object or phenomenon from a distance,
without actually coming in contact with the object
under study.
The quantity most frequently used in present day
remote sensing systems is the Electromagnetic
Energy emanating from the object of interest.
Principally, there are two types of Remote Sensing
viz. Active and Passive Remote sensing.
It has two phases: Data acquisition phase and Data
analysis phase.
The underlying principle on which the whole
Remote Sensing technique is developed is that all
objects on the Earth’s surface have characteristic
spectral signatures.
The applications of Remote Sensing in the Earth’s
science as a whole, especially in Geology is
manifold.
BOOKS:
A.N. Patel and Surendra Singh, “Principles of Remote
Sensing” Edition-1999, Page No. 1, 27, 113.
Scientific Publishers (India), Jodhpur.
Basuded bhatta, ”remote sensing and
GIS”2008,2011,oxford university press.
Flyod F .Sabins, “ remote sensing,principles and
interpretation,1996.3rd edition .
Hinweis der Redaktion
APPLICATIONS OF REMOTE SENSING IN GEOLOGICAL ASPECTS