So far IRS-1A has provided more than 2 lakh high quality data products of which 
50,000 products have been effectively used in various applications of natural 
resources, cartography, environment, engineering applications and coastal 
oceanography. The data products are available in a variety of formats, ranging from 
70 mm "quick look" film products (level 0) to user-specified digitally enhanced 
special products (level 4) (DOS, 1989). 
1.3 Information content and planimetric fidelity of IRS-1A data 
Analysis were carried out to compare the information content of IRS LISS-II data 
with SPOT and Landsat-TM bands. Statistical techniques viz., Entropy, Principal 
Component Analysis and Correlation Analysis were performed. The results indicate 
that (i) with respect to Entropy and percentage of information content for visible 
channels of LISS-II data was found marginally superior to the SPOT and TM data and 
with respect to NIR channel data, all the three data sets performed equally (ii) 
correlation analysis indicated similar correlation between bands of all the 3 
sensors (iii) PC results showed that information content in PC-1 of LISS-II was 
higher (81%) than the information content of PC-1 of SPOT (67%) and PC-1 of TM data 
(74%) (Table 2 & 3) (Bhan, et.al, 1989). 
TABLE - 2 : ENTROPY AND PERCENTAGE OF INFORMATION 
Sensors 
Blue 
Spectral Channels 
Green Red NIR 
Maximum possi 
ble Entropy 
SPOT-XS 
1.99 
4.33 
4.72 
7.99 
(49.94) 
(54.19) 
(50.07) 
LS-TM 
4.56 
3.9 
4.54 
4.85 
7.99 
(57.07) 
(48.81) 
(56.82) 
(60.8) 
IRS-1A 
4.54 
4.26 
4.96 
4.17 
7.00 
(64.86) 
(60.86) 
(70.86) 
(59.57) 
TABLE - 3 
: MATRIX OF CORRELATION COEFFICIENTS 
Sensor 
Bands 
1 
2 
3 
4 
SPOT-XS 
1 
1 
2 
0.96 
1 
3 
0.09 
o 
0 
1 
1 
- 
LS-TM 
1 
1 
2 
0.90 
1 
3 
0.91 
0.95 
1 
4 
-0.25 
-0.08 
-0.21 
1 
IRS-1A 
1 
1 
LISS-II 
2 
0.97 
1 
3 
0.92 
0.94 
1 
4 
-0.19 
-0.04 
-0.11 
1 
In the field of cartography it has been observed that LISS-II data with regard to 
planimetric fidelity is as accurate as Landsat TM and SPOT. The rectified resampled 
IRS LISS-II is found useful as a stereo-mate with high angle SPOT data. For the 
purpose of map updating, it is found 75% of the roads could be transferred on 
1:50,000 scale using IRS-1A LISS-II data. (Kesavaswamy, 1988, Dutt, 1988, Rajashree, 
1988, Srivastava, 1988). Thus information content of the IRS-1A LISS-I data was 
found comparable with Landsat MSS and Landsat TM with comparable spectral bands 
data, the clarity and sharpness of features are found better on IRS-1A data due to 
better radiometric quality and higher S/N ratio of the IRS-1A data. 
2.0 APPLICATION POTENTIALS OF IRS-1A DATA 
With such high quality of data available from IRS-1A sensors, numerous application 
studies have been carried out. The potential applications of IRS data has been 
tested for a wide range of natural resources applications including agriculture, 
cartography, environment, coastal oceanography, flood management, desert 
advancement, river morphology etc. Presently 70% of the user demands in India are 
met through IRS-1A data and it is constantly on the increase. The results presented 
herein are based on the case studies carried out during the last two years to 
evaluate the suitability of IRS-1A data with that of Landsat MSS, TM and SPOT data 
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