India's eye in the sky is set to become sharper and wider with the launch of a third satellite in the Cartosat-2 series -- a dedicated satellite for the defence forces -- from the Sriharikota spaceport on Friday.
How sharp is Cartosat’s resolution?
Cartosat 2, the latest remote-sensing satellite launched on Friday, has a resolution of 0.6 m. This means it can spot even smaller objects. “It can recognise objects within a 0.6 m by 0.6 m square", an official of the Indian Space Research Organisation (ISRO) said, speaking on condition of anonymity.
How is the Cartosat imagery useful?
Cartosat-2 is a remote-sensing satellite. Its objective is to provide high-resolution scene-specific spot imagery. The images sent by the satellite would be useful for cartographic applications, urban, rural and coastal land use and regulation, utility management like road network monitoring, water distribution, creation of land use maps, change detection to bring out geographical and man-made features and various other land information systems (LIS) as well as geographical information systems (GIS).
Cartosat-2 satellites can take pictures of any place that you want. You can choose the required imagery and programme the satellite.
Why do we need our own imaging satellites?
Cartosat-2 can produce images of up to 100 cm in resolution (black and white), compared to the 80 cm offered by Ikonos from which India used to buy images in the past. But Ikonos used to charge about $20 per square km of imagery. India buys images worth about Rs 2 crore per year from Ikonos. Cartosat-2 offers better resolution at 20 times less cost.
Can Cartosat help India tackle terror?
The previous satellite in the Cartosat series had a resolution of 0.8 m. The images it took of India's neighbourhood helped New Delhi to carry out surgical strikes on terror launch pads across the Line of Control last year.
The satellite can provide India’s defence forces scene-specific imagery in the military’s area of interest. Indian can thus track developments along the borders with China and Pakistan. It can help detect changes in man-made or geographical features along its land and maritime borders.
"Cartosat 2 will give a leg up to our defence surveillance. It can be used to identify terrorist camps and bunkers and some enemy formations," the source added.
When the latest Cartosat 2 becomes operational, some of its systems will be handed over to the defence forces, which have their own arrangements to make use of it, including ground stations and trained manpower to access and process data.
However, the Indian military wants more dedicated satellites for exclusive military use. So far, only the Indian Navy has a dedicated satellite. India has moved towards network-centric warfare in which land, air and sea defence forces are networked through space technology and surveillance aircraft.
How many Cartosats has India launched?
Friday’s launch deployed the sixth satellite in the Cartosat series. The first launch took place in January 2007.
However, the first dedicated military satellite, CartoSat-2A, was launched in April 2008, followed by CartoSat-2B in July 2010. The series’ latest three satellites have been deployed over the space of a year and a day: Cartosat-2C was launched on 22 June 2016, Cartosat-2D on Feb. 15 February this year. Cartosat -2E was launched on Friday. All of them rode on PSLV rockets.
Cartosat-2E will likely be the last Cartosat-2 series spacecraft. A follow-on series, Cartosat-3, is due to begin launching next year.
However, these names are informal names. India has stopped naming these spacecraft individually. Instead they are described as the Cartosat-2 series. Informally, Friday’s spacecraft is known as Cartosat-2E.
Does Cartosat have only military applications?
Cartosats are designed for earth observation. They have both military and civilian applications. It is not clear whether the latest launch, Cartosat-2E, will be used for civilian or military imaging, or both. ISRO literature indicates a more civilian role for the latest spacecraft than its predecessors in the series. However, all countries tend to be circumspect when giving out details of military spacecraft operations.
Why do we need so many Cartosats?
So far, six Cartosats have been launched by India. An ISRO official explained that the revisit time of a satellite is what determines your data accessibility. A satellite’s revisit time is the time elapsed between two serial observations of the same point on earth. It depends on the satellite's orbit, target location, and swathe of the sensor. So, the more satellites a country sends up, the better the data generated.