Swan(sea) Song – personal research during my six years at Swansea ... and bey...
Ocean- sat for Oceanography
1.
2.
3.
4. A geostationary satellite is an earth-orbiting satellite,
placed at an altitude of approximately 35,800 kilometers
(22,300 miles) directly over the equator, that revolves in
the same direction the earth rotates (west to east).
At this altitude, one orbit takes 24 hours, the same length
of time as the earth requires to rotate once on its axis.
Example: INSAT-3A, INSAT-4B, INSAT-3C, INSAT-3E, KALPANA-
1, INSAT-4A, INSAT-4CR,GSAT-8, GSAT-12 and GSAT-10 etc.
Image credit : ISRO
8. Launch date May 26, 1999
Launch site SHAR, Sriharikota
Launch vehicle PSLV - C2
Orbit Polar Sun Synchronous
Altitude 720 km
Inclination 98.28 deg
Period 99.31 min
Local time of Eq. crossing 12 noon
Repetitivity cycle 2 days
Size 2.8m x 1.98m x 2.57m
Mass at lift off 1050 kg
Length when fully deployed 11.67 m
Attitude and Orbit Control 3-axis body-stabilised using Reaction Wheels, Magnetic Torquers and
Hydrazine Thrusters
Power 9.6 Sq.m Solar Array generating 750w Two 21 Ah Ni-Cd Batteries
Mission Completed On August 8, 2010
9.
10. Parameter Specification
1. IGFOV at nominal altitude (m) 360 x 250
2. Swath (km) >1420
3. No. of spectral bands 8
4. Spectral range (nm) 402-885
5. Spectral band Central wavelength (bandwidth) in nm Saturation radiance (mw cm-2 sr-1 µm-1)
C1 414 (20) 35.5
C2 442 (20) 28.5
C3 489 (20) 22.8
C4 512 (20) 25.7
C5 557 (20) 22.4
C6 670 (20) 18.1
C7 768 (40) 9.0
C8 867 (40) 17.2
6. Quantisation bits 12
7. Camera MTF (at Nyquist frequency) >0.2
8. Data rate (Mbits s-1) 20.8
Along Track Steering +20, 0, 20
Major specifications and features of IRS-P4 : OCM
15. Specification of the OCM instrument
Parameter Value Parameter Value
Spectral range (8 bands) 0.4 - 0.9 µm (VNIR) SNR > 512 (saturation)
Scan plane tilt ±20º,to avoid sun glitter Effective focal length 20 mm
Camera MTF >20% at Nyquist frequency Absolute radiometric accuracy <10%
IFOV at nadir (spatial resolution) LAC: 360 m x 236 m
GAC: 1 km
No of CCD elements 6000
FOV (swath) 1420 km (±43º) CCD element size 10 µm x 7 µm
Tilt capability ±20º along track Integration time 52.4 ms
Data quantization 12 bit Exposure levels (gain) 16
Data rate (real-time) 20.8 Mbit/s Onboard calibration 2 LEDs per band
Instrument mass 78 kg Instrument power 134 W
19. Parameter Inner beam Outer beam
Orbiting altitude 720 km
Frequency 13.515 GHz (Ku-band)
Wind speed range 4-24 m/s with accuracy of 2 m/s (rms)
Wind speed accuracy Better than 20 % (rms)
Wind direction accuracy 20º (rms)
Resolution 50 km x 50 km
Polarization HH VV
Swath width 1400 km 1840 km
Scanning circle radius 700 km 920 km
Elevation angle (look angle) 42.62º 49.38º
Incidence angle 48.90º 57.60º
Footprint 26 x 46 Km 31 x 65 Km
Scanning rate 20.5 rpm
22. Frequencies of operation L1: 1560 - 1590 MHz;, L2: 1212 - 1242 MHz
GPS codes used C/A and P code
Dual-frequency channels (navigation) 16 max (without observation mode), 8 max (in observation mode)
Dual-frequency channels (observation) 8
Doppler shift
Doppler rate
Doppler acceleration
± 50 kHz
± 110 Hz/s
± 0.5 Hz/s
2
Antenna gain + 5 dBi for navigation antenna, + 12 dBi for RO (Radio Occultation) antenna
Polarization RHCP
Horizontal resolution < 300 km for temperature and humidity
Vertical resolution 0.3 km (low troposphere), 1-3 km (high troposphere)
Accuracy < 1.0 K temperature , 10% or 0.2 g/kg humidity
Input signal range 127 to -133 dBm POD antenna, 130 to -148 dBm RO antenna
Instrument mass, power 17 kg, 36 W (standby) and 38 W (operation)
Data interface Data/Command: MIL-STD-1553B, PPS output: RS-422 (dedicated receiver connector)
Dimensions Receiver: 287 mm x 250 mm x 206 mm, Radio occultation antenna: 1035 mm x 500 mm x
165 mm, Navigation antenna: 127 mm x 49 mm
23.
24. Acronym OceanSat-3
Full name OceanSat-3
Satellite Description •3rd flight unit of the OceanSat programme.
•Main mission: ocean observation.
Mass at launch 960 kg Dry mass
Power 1360 W
Data access link no link provided
Data access
information
•NRT product access under consideration by ISRO and EUMETSAT
•Off-line data are distributed by the National Remote Sensing Center
(NRSC) in Hyderabad. Web site: www.nrsc.gov.in.
Orbit Sunsynchronous orbit Altitude 723 km
ECT 12:00 desc
25. Acronym OceanSat-3A
Full name OceanSat-3A
Satellite Description •4th flight unit of the OceanSat programme.
•Main mission: ocean observation.
Mass at launch 960 kg Dry mass
Power 1360 W
Data access link no link provided
Data access
information
•NRT product access under consideration by ISRO and EUMETSAT
•Off-line data are distributed by the National Remote Sensing Center
(NRSC) in Hyderabad. Web site: www.nrsc.gov.in.
Orbit Sunsynchronous orbit Altitude 723 km
ECT 12:00 desc