1. Remote Sensing andGIS

2. Introduction of Remote Sensing
Definition
History of Remote Sensing
Basic components of Remote sensing
Electromagnetic Remote Sensing Process
Electromagnetic spectrum
Passive and active remote sensing

3. Different types of Resolution
Spatial Resolution
Spectral Resolution
Radiometric Resolution
Temporal Resolution
Characteristics of various sensors
Satellites: IRS
Fundamentals of Image Processing

4. Component of Remote Sensing
Energy Source or Illumination (A)
2. Radiation and the Atmosphere (B)
3. Interaction with the Target (C)
4. Recording of Energy by the Sensor (D)
5. Transmission, Reception, and Processing (E)
6. Interpretation and Analysis (F)
7. Application (G)

5. Electromagnetic Radiation
Two characteristics of electromagnetic Radiation
wavelength
frequency.

6. The Electromagnetic Spectrum
There
are several regions of the electromagnetic spectrum which are useful for remote sensing
For most purposes, the ultraviolet or UV
portion of the spectrum has the shortest
wavelengths which are practical for remote
sensing. This radiation is just beyond the
violet portion of the visible wavelengths,
hence its name. Some Earth surface
materials, primarily rocks and minerals,
fluoresce or emit visible light when illuminated
by UV radiation.

7. Ex. Assume the speed of light to be 3x108 m/s
Ex. Assume the speed of light to be 3x108 m/s. If the frequency of an electromagnetic wave is 500,000 GHz (GHz =gigahertz = 109 m/s), what is the wavelength of that radiation? Express your answer in micrometres (μm).

9. Problems
Ex . A given SLAR system transmits pulses over a duration of Find the range resolution of the system at a depression angle 450
Ans: 21m
Ex. A given SLAR system has a 1.8 mrad antenna beamwidth. Determine the azimuthal resolution of the system at ranges of 6 km and 12 km
Ans: 10.8 m & 21.6 m
Ex. A given SLAR system has a 2 mrad antenna beamwidth and wavelength of the transmitted pulse is 5 cm. Determine the length of the antenna
Ans: 25 m

10. SLAR
The deficiencies of brute force operation are overcome in synthetic aperture radar (SAR) systems.
Having short physical antenna through modified data recording and processing techniques, but synthesize the effect of a very long antenna.
The result of this mode of operation is a narrow effective antenna beamwidth, even at far ranges, without requiring physically long antenna or a short operating wavelength.
At the detailed level, the operation of SAR systems is quite complex
This concept shown in Figure

11. Fig. Concept of an array of real antenna positions forming a synthetic aperture

13. Operate on the principle of using the sensor motion along track to transform a single physically short antenna into an array of such antennas that can be linked together mathematically as part the data recording and processing procedures
The "real" antenna is shown in several successive
positions along the flight line.
These successive positions are treated mathematically as if they are simply successive elements of a single long synthetic antenna

14. Fig. Variation of spatial resolution of
a) SLAR
b) SAR