Remote Sensing Essentials
Rudiments of Remote Sensing and advantages
Dr. Arun K. Saraf,
Professor
Department of Earth Sciences
1
REMOTE SENSING
 Remote
sensing is the technology of acquiring
information about the Earth's surface without
actually being in contact with it.
 This
is done by sensing and recording
reflected or emitted energy and processing,
analyzing, and applying that information.
2
REMOTE SENSING
A.
B.
C.
D.
E.
F.
G.
Energy Source or illumination
Radiation and the atmosphere
Interaction with the target
Recording of energy by the sensor
Transmission, reception, and processing
Interpretation and analysis
Applications
3
Present Day Remote Sensing Platforms
4
5
REMOTE SENSING
Remote sensing process involves an
interaction between incident radiation and
the targets of interest.
This is exemplified by the use of imaging
systems where the following seven
elements are involved.
6
7
Remote Sensing
A. Energy Source or Illumination – the first
requirement for remote sensing is to have an
energy source which illuminates or provides
electromagnetic energy to the target of interest.
B. Radiation and the Atmosphere – as the energy
travels from its source to the target, it will come
in contact with and interact with the
atmosphere it passes through. This interaction
may take place a second time as the energy
travels from the target to the sensor.
8
Remote Sensing
C.
D.
E.
Interaction with the Target - once the energy makes
its way to the target through the atmosphere, it interacts
with the target depending on the properties of both the
target and the radiation.
Recording of Energy by the Sensor - after the energy
has been scattered by, or emitted from the target, we
require a sensor (remote - not in contact with the target)
to collect and record the electromagnetic radiation.
Transmission, Reception, and Processing - the
energy recorded by the sensor has to be transmitted,
often in electronic form, to a receiving and processing
station where the data are processed into an image
(hardcopy and/or digital).
9
Remote Sensing
F.
Interpretation and Analysis - the processed
image is interpreted, visually and/or digitally or
electronically, to extract information about the
target which was illuminated.
G.
Application - the final element of the remote
sensing process is achieved when we apply the
information we have been able to extract from
the imagery about the target in order to better
understand it, reveal some new information, or
assist in solving a particular problem.
10
REMOTE SENSING: ADVANTAGES









Synoptic view
Global coverage
Repeatability
Multispectral: Sensors can measure energy at wavelengths beyond
range of human vision
Multi-resolution
Near Real-time
Systematic data collection
The only solution sometimes for the otherwise inaccessible areas
Generic data: Multipurpose purpose datasets
11
Advantages of remote sensing technology
•
•
•
•
•
•
Processing and analysis is fast
Microwave remote sensing can penetrate clouds and dry sand
Optimizes field investigations
Updating / revision of exiting maps is inexpensive and faster
Color composites ensure the details of the area
In natural disasters studies and rescue mission becomes easy
and fast
• Overall cost effective
12
REMOTE SENSING: ADVANTAGES
1. Remote sensing is UNOBTRUSIVE if the sensor passively records the EMR
reflected or emitted by the object of interest. Passive remote sensing does
not disturb the object or area of interest.
2. Remote sensing devices may be programmed to collect data systematically,
such as within a 10 x 10 km frame of vertical aerial photography. This
systematic data collection can remove the sampling bias introduced in some
in situ investigations.
3. Under controlled conditions, remote sensing can provide fundamental
biophysical information, including x,y location, z elevation or depth, biomass,
temperature, and moisture content.
13
THANKS
14