A new set of future satellites called hyperspectral imaging
satellites is set to add teeth to the way India will be seen from about 600 km
in space.
The
Indian Space Research Organisation (ISRO) says it plans to launch a
full-fledged niche earth observation (EO) satellite — called the Hyperspectral
Imaging Satellite or HySIS — using a critical chip it has developed.
There
is no specific time-frame yet for its launch, an ISRO spokesman said, adding
that meanwhile, the new chip, technically called an “optical imaging detector
array,” that they have created for it would be tested and perfected. “ISRO is
endeavouring to enter the domain of operational hyperspectral imaging from
earth orbit with a satellite that can see in 55 spectral or colour bands from
630 km above ground,” ISRO has said. It said it decided to develop the chip
that suited Indian requirements.
Hyperspectral
or hyspex imaging is said to be an earth observation trend that is being
experimented globally. Adding a new dimension to plain-vanilla optical imagers,
it can be used for a range of activities from monitoring the environment,
crops, looking for oil and minerals all the way up to military surveillance —
all of which need images that show a high level of differentiation of the
object or scene.
About
a decade ago, ISRO added another earth observation niche with microwave or
radar imaging satellites RISAT-1 and 2 that could ‘see’ through clouds and the
dark — an important feature useful for the military and security agencies.
‘Hyspex’
imaging is said to enable distinct identification of objects, materials or
processes on earth by reading the spectrum for each pixel of a scene from
space.
Another
official described it as “another important development by ISRO in its quest
for better and diverse earth observation technologies.”
ISRO
first tried it out in an 83-kg IMS-1 experimental satellite in May 2008. The
same year, a hyperspectral camera was put on Chandrayaan-1 and used to map
lunar mineral resources. Very few space agencies have such a satellite; a
German environmental satellite called EnMAP is due to be launched on an Indian
booster in 2018.
The
payloads development centre, Space Applications Centre, Ahmedabad, designed the
architecture of the chip which was made at ISRO’s electronics arm, the
Semi-Conductor Laboratory, Chandigarh. The result was a detector array that
could read 1000 x 66 pixels.
According
to an EO expert who called it the ‘CATSCAN’ equivalent of Earth from space,
hyspex technology was still an evolving science.
Source: THE HINDU-10th August,2017
