Remote Sensing

Remote Sensing


In Remote Sensing an era of high resolution imagery seems to gear up. Last year ImageSat launched EROS-1 successfully, this year has seen the launch of QuickBird by DigitalGlobe. India also joined the race by launching a Test Experimental Satellite.

DigitalGlobe launches QuickBird
Earth Watch now renamed as DigitalGlobe has successfully launched and deployed the QuickBird high-resolution remote sensing satellite in October 2001. QuickBird provides the highest resolution, commercially available, satellite imagery and the foundation for a wide array of information products. QuickBird acquires 61-centimetre (2-foot) resolution panchromatic (black and white) and 2.44-metre (8-foot) multispectral (colour) imagery. At 61-centimetre resolution, buildings, roads, bridges and other detailes like footpath, boundary wall etc. become visible.

EROS A1 launched by Israel and marketed by ImageSat International, carries a camera with a focal plane of CCD (Charge Coupled Device) detectors with 7,800 pixels per line, and produces a panchromatic image with a resolution of 1.8 m. It was launched in December 2000 and began selling imagery in August 2001. The EROS A-class satellites provide a swath of at least 12.5 km in width. EROS A1 is the first of a constellation of 7 satellites that are planned to be placed in orbit in the next few years starting from EROS BE scheduled for launch in 2003 will provide half metre imagery.

Space Imaging “Half-Meter Resolution” License Approved
The U.S. National Oceanic and Atmospheric Administration (NOAA) has granted Space Imaging Inc. license to sell high-resolution satellite photographs to its customers around the world, after a year-long policy review by the White House, Pentagon, State Department and intelligence community in January 2001. The license prohibits the firm from providing customers with satellite pictures within 24 hours of the time they are taken. The U.S. government reserves the right to ‘shutter ‘commercial satellites to protect national security, as well as any time “international obligations or foreign policy interests may be compromised.” Space Imaging plans to launch its next-generation imaging satellite in 2004, offering “half-meter resolution”.

Hyperion sending data to Earth
Hyperion, the NASA’s first hyperspectral imager launched in December 2000 became operational on-orbit and started making the imageries available in January 2001. Data from Hyperion is providing more detail of the Earth’s surface than is currently available from multispectral instruments, such as the Enhanced Thematic Mapper Plus instrument on Landsat 7. The detailed classification of complex land ecosystems with hyperspectral imagery is expected to increase the accuracy of remote sensing data in applications including mining, geology, forestry, agriculture and environmental management. Using hyperspectral data, minerals on the Earth’s surface can be identified and new mineral maps can be created to select sites for exploration; forest inventories can be developed for remote regions to support ecological planning and management.

TES experiment satellite
The successful launch of the Technology Experiment Satellite (TES) by the Polar Satellite Launch Vehicle (PSLV-3) is a mission made possible by Indian Space Research Organisation in October 2001. The TES is a major technological advancement for India especially in the field of Earth Observation. The capability of 1 metre high resolution has raised the expectation of high-resolution imagery becoming available for civilian projects in India at economical cost. Although there are speculations regarding the use of the satellite for military purposes.