CARTOSAT-1

CARTOSAT-1CARTOSAT-1 spacecraft was launched on May 5, 2005 by ISRO's Polar Satellite Launch Vehicle (PSLV-C5) from Sriharikota, India. The CARTOSAT-1 mission ensured data continuity while introducing improvements in the spatial, spectral and radiometric resolutions. CARTOSAT-1 is launched into a near polar sun-synchronous orbit of 618 km altitude. The local time of pass is 10:30 AM ± 10 minutes. This satellite carries two PAN sensors with 2.5m resolution and fore-aft stereo capability. The payload is designed to cater to applications in cartography, terrain modeling, cadastral mapping etc. The major orbital parameters are given below:

Altitude 618Km, polar sun synchronous
Orbits /cycle 1867
semi major axis 6996.14 km
Eccentricity 0.001
Inclination 97.87°
Orbits /day 14
Period 97 minutes
Equatorial crossing time 10:30 A.M ± 10 minutes
Revisit 5 days
Repeativity 126 days

Cartosat-1 is a unique stereoscopic mission with the capacity of acquiring along track stereo images with fixed B/H ratio. The satellite was launched aboard PSLV-C6 on May 5, 2005 from SDSC Sriharikota. Cartosat-1 data is used widely by National and International community for applications related to infrastructure, urban Development, Forestry, Watershed analysis etc. Cartosat-1 has also supported the international requirements through the International Ground Stations (IGS). Cartosat-1 scientific Appraisal Programme (CSAP) has published various reports / papers showcasing the Cartosat-1 standards vis-a-vis international standards / data. Cartosat-1 has successfully completed 10 years of life in the orbit. To commemorate this important event, a one day seminar is planned on May 5, 2015 to recapitulate the success story of Cartosat-1 and plan for the future missions. Download Cartosat-1: Ten Years in Orbit: Compendium.

Instruments

CARTOSAT-1 carries two payloads: 1) Fore Camera. 2) Aft Camera. These two panchromatic cameras with 2.5 m spatial resolution, are to acquire two images simultaneously, one forward looking (FORE) at +26 degrees and one aft of the satellite at -5 degrees for near instantaneous stereo data.The time difference between the acquisitions of the same scene by the two cameras is about 52 seconds. The platform is continuously steerable about spacecraft body-yaw to compensate the earth rotation correction and thus allow both Fore and Aft cameras to look at the same ground strip with certain time gap, of the order of 52 seconds, providing stereoscopy. The payload can be operated either in real time mode by direct transmission to ground station or in Record- Playback mode using a 120 Gb On-Board Solid State Recorder (OBSSR). The various modes of payload operations can be programmed apriory, through the Tele Command Processor (TCP). The Specifications are given in below:

Parameters PAN-F PAN-A
IGFOV (meters) 2.452 2.187
No. of Detectors 12 k 12 k
Swath 29.42 Km 26.24 Km
Spectral band (micron) 0.5 - 0.85 0.5 - 0.85
Saturation radiance (mW/cm2/sr/µm) 55 55
Tilt Angle +26° -5°
SNR (at saturation) 345 345
Quantization (bits) 10 10
Data Rate (Mbits/s) 105 105
Data compression JPEG , compression ratio=3.22 (max) JPEG , compression ratio=3.22 (max)
MTF cross-track=20, along-track=23 cross-track=20, along-track=23

The Fore camera (PAN-F Forward-pointing Camera) provides an across track resolution of 2.452 m (at Nadir). It covers a swath of 29.42 km. The Fore camera can be tilted upto + 23 degrees in the across track direction, thereby providing a revisit period of 5 days. The resolution of the camera when tilted by 25 deg is 2.909m, resulting in a swath of 34.91 km. The Data of relative spectral response (RSR) is provided on request. The Aft camera provide an across track resolution of 2.187 m (at Nadir). It covers a swath of 26.24 km .The Aft camera can be tilted upto + 23 degrees in the across track direction, thereby providing a revisit period of 5 days. The resolution of the camera when tilted by 25 deg is 2.789 m, resulting a swath of 33.47 km. The Data of relative spectral response (RSR) is provided on request. The Aft camera provide an across track resolution of 2.187 m (at Nadir). It covers a swath of 26.24 km .The Aft camera can be tilted upto + 23 degrees in the across track direction, thereby providing a revisit period of 5 days. The resolution of the camera when tilted by 25 deg is 2.789 m, resulting a swath of 33.47 km. The Data of relative spectral response (RSR) is provided on request.

PAN-F Relative Response Curves and Data Coverages


Data Products


Cartosat-1 data products are of two categories. 1) Standard product (radiometrically corrected, georeferenced) 2) Precision product (ortho rectified product) Standard products are generated after accounting for radiometric and geometric distortions while precision products are ortho rectified. Ortho rectified products are corrected for terrain distortions and camera tilt effects with the help of control points and using Stereo Strip Triangulation (SST) based DEM (only for Indian region). All Cartosat-1 data products are supplied with 10 bit radiometry for both PAN Fore and Aft cameras. Area of Interest (AOI) based standard products One or more scenes covering the user's area of interest, specified as a single polygon in the form of an ESRI shapefile, are provided as tiled products (not mosaiced). The user-specified polygon (order polygon) is padded outside with extra buffer distance to ensure the area coverage, considering the accuracy specifications of the system corrected product. The modified polygon boundaries are used to define each constituent full/sub-scene product. The different tiles are not radiometrically matched. The minimum order area is 25 km x 25 km. The location accuracy of these products is better than 250m. All AOI based products are provided as digital products(CD/DVD) only. AOI products are available for only radiometrically corrected or Georeferenced data. Ortho kit products are supplied with only radiometric corrections. A file consisting of the rational polynomial coefficients (RPC) is also provided for further processing at user,s end. An orthokit product consists of an image file (GeoTIFF format), an RPC file (text file) and a metadata file.Orthokit products facilitate the user to produce high precision products by using control points / external DEM in the commercially available off-the-shelf (COTS) software. It is recommended to use software packages, certified by Department of Space, for better results.Scene based stereo products are supplied with only radiometric corrections. Stereo data are supplied as digital products only. These products can be supplied in LGSOWG format and in GeoTIFF format with RPCs. In the case of stereo data in LGSOWG format, radiometrically corrected data from both Fore and Aft cameras are provided. Stereo data in GeoTIFF format comprise of radiometrically corrected data from both Fore and Aft cameras and an RPC file. These products facilitate the user to produce high precision products and extract digital elevation models (DEM). The location accuracy of the products is better than 250m. It is recommended to use software packages, certified by Department of Space,for better results. Precision geo-referenced products are mosaiced and ortho rectified products. These products can be supplied with different area coverages 7 ½, x 7 ½,(both Survey of India (SOI) mapsheet based and floating), 5, x 5,, 3.75, x 3.75, and 2.25,x 2.25,. All these products are supplied as a single product. Best efforts are made to provide the data with seamless radiometry in case the area is covered on two different dates.The location accuracy of these products will be better than 25m. For global users, these products can be supplied with the help of GCPs provided by the user.

Types of products


Data Ordering

Users can browse and order data online through User Order Processing System (UOPS) provided at NRSC web site. The data requirements for future dates and geographical areas beyond the visibility circle of Shadnagar Earth Station facility will be serviced through on-board Solid State Recorder. It is possible to provide raw data for the user specified areas and period of interest along with the data processing software. This concept is known as virtual station. For such data requirements, users can contact Antrix corporation.


Sample Images

Documents

Contact Us

Group Head, SDPQAG
National Remote Sensing Centre
Phone: +91 40 23884428, 09490704753
Email: chandrasekharan_d[at]nrsc[dot]gov[dot]in

 

CARTOSAT-1