| Satellites: : Aryabhata | APPLE | INSAT-1
| INSAT-2
| INSAT-3
| Bhaskara
| IRS | Rohini Launcher
: : SLV
| PSLV | ASLV | GSLV
IRS Series : : IRS-1A | IRS-1B | IRS-1C | IRS-1D | IRS-1E | IRS-P1 | IRS-P2 | IRS-P3 | IRS-P4 | IRS-P5 | IRS-P6 | IRS 2A | IRS-2B | IRS-3
IRS-1C Satellite
(Click here
for image)
This is one of the best satellites having
highest spatial resolution of 5.8 m in
Panchromatic and 23.5 m in multispectral.
Orbit Details
Launch date : Dec. 28, 1995 (Soviet
Launcher Molniya used)
Altitude : 817 Kms.
Inclination : 99.049 degrees
Period : 101.35 minutes
Repetivity : 24 days (5 days - revisit)
Equatorial crossong time : 10.30 AM
descending
Weight : 1250 Kg.
No. of Sensors : Three; 1) PAN, 2)
LISS-III and 3) WiFS
Panchromatic Camera (PAN)
| Parameters
|
Specifications
(PAN) |
| Band
(microns) |
0.50 - 0.75 |
| Resolution
(m) |
5.8 |
| Effective
focal lenght |
980 mm |
| Coding |
6 bits (64
grey levels) |
| Camera SWR |
0.2 |
| SNR (at
saturation radiance) |
>64 |
| Data rate
(MBPS) |
84.903 |
Swath (km.)
1. Nadir
1. Off-nadir |
70
91 |
| Off-nadir
viewing (deg) |
+/-26 for
obtaining stereoscopic data and 5 day
revisit |
| Steering
step size (deg) |
0.09 |
The data in the panchromatic
region is useful in geological studies for
mapping geological and geomorphological features.
Higher spatial resolution will be useful for
urban planning studies, detecting urban fringe
growth, updating the urban transporation
infrastructure etc. It is having off-nadir
viewing capability and the view angle can be
varied between +/- 26 deg. The advantages of
off-nadir viewing are increased repetivity
coverage and stereoscopy. Stereoscopic image pair
obtainable by PAN can be used for topographic
studies and generation of digital terrain models.
Imaging Sensor Characteristics ( LISS-III
Sensor)
| Parameters
|
B2 B3 B4 |
B5 |
| Spectral
bands |
0.59-0.59(green)
0.62-0.68(reg) 0.77-0.86(NIR) |
1.55-1.70
(MID) |
| Resolution
(m) |
23.5 (for
bands B2,B3,B4) |
70.5 (for
b5) |
| CCD devices |
6000
elements |
2100 |
| Swath (Kms) |
141 |
148 |
| Equi focal
length (mm) |
347.5 |
301.2 |
| Number of
grey levels |
128 (7 bits)
|
128 |
The bands are similar to the
IRS-1A, IRS-1B and IRS-P2 except blue band which
is not included in IRS-1C.
Band 2 is centered around the first
peak of the vegetation reflectance curve (refer
to reflectance curves in standard books) and is
useful for discrimination of vegetation. This
band along with red and near IR regions forms the
core data useful for discrimination of
vegetation.
Band 3 is centered around the
chlorophyll absorption region of vegetation.
Strong correlation exists between spectral
reflectance in this region and chlorophyll
content. A reduction in the amount of chlorophyll
can occur when the plant is stressed. This
results in less chlorophyll absorption and an
increase in red reflectance. This band along with
the near IR band is used widely for deriving
spectral indices like ratio and Normalised
Difference Vegetation index (NDVI) which have
been found to be very good indicators of crop
vigour and biomass.
Band 4: The high reflectance plateau
region of the vegetation reflectance is in this
band. Plant reflectance in this region is highly
governed by the internal structure of plant
leaves. This band shows high reflectance for
healthy vegetation and is useful for green
biomass estimation and crop vigor.
Band 5: the middle infra-red region
from 1.3-2.5 microns is sensitive to leaf water
content. It has been shown that 1.55 - 1.70 is
best suited in 0.7-2.5 region for monitoring
plant canopy water status. Major applications of
this band include discrimination of crop types,
canopy water status, forest type separation and
damage assessment. Crop classification accuracies
can be improved by 1-15% when this band is
included with other bands. Also useful snow-cloud
discrimination. In geology, it will be useful for
rock type discrimination.
Wide Field Sensor (WiFS)
| Parameters
|
Values |
| Spectral
bands (microns) |
B3 -
0.62-0.68 (red)
B4 - 0.77-0.86 (near IR) |
| Resolution
(m) |
188 |
| CCD devices |
2048
elements |
| Swath (Kms) |
810 (5 days
repetivity) |
| Equivalent
focal length (mm) |
56.4 |
| No. of grey
levels |
128 (7 bits)
|
| SNR |
>128 |
This sensor is most useful for
vegetation studies. With larger swath (770 Km),
high repetivity ( 5 days) and operation in two
vegetation specific bands, the sensor provide
vegetation index at regional level, thus helping
in assessment of crop condition and drought
monitoring.
Sources and Resources
- Other source : www.bharatrakshak.com
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