The launch will give impetus to satellite photogrammetry

The launch will give impetus to satellite photogrammetry


V Jayaraman
V Jayaraman
Director, Earth Observation System (EOS),
Indian Space Research Organisation

With CARTOSAT-I, India has once again made a mark in the international Remote Sensing arena. Kindly comment.
CARTOSAT-I has re-affirmed ISRO’s commitment and leading position in space technology in the world. From the early days of the IRS series to the emergence of the high-resolution market till today, where CARTOSAT-I has been launched, ISRO has maintained it unique image of being one of the most advanced space technology enablers of the world. CARTOSAT-I is a modern remote sensing satellite, which is mainly intended for cartographic applications. The data from CARTOSAT-1 is expected to provide enhanced inputs for large scale mapping applications and stimulate newer applications in development.

How do you think CARTOSAT has an edge over other satellites in the market?
CARTOSAT-I is the eleventh satellite to be built in the Indian Remote Sensing (IRS) satellite series. Weighing 1560 kg at lift-off, CARTOSAT-1 was launched into a 618 km high polar Sun Synchronous Orbit (SSO) by PSLV-C6. CARTOSAT-I can be called unique because of its ability to generate accurate heights and DEMs with simultaneous imaging techniques. It basically gives us a new concept that will give new impetus to satellite photogrammetry. The spacecraft is configured with two Panchromatic cameras which are mounted such that one camera is looking at +26 deg. w.r.t. nadir and the other at -5 deg. w.r.t. nadir along the track. These two cameras combined provide stereoscopic image pairs in the same pass. Also the whole spacecraft is steer-able across track to provide wider coverage in a shorter period. With RESOURCESAT and CARTOSAT-1 data put together, we can generate P+Xs images. CARTOSAT-1 data will enable generation of maps at 1:25,000 scales and thematic mapping at better than 1:10,000 scales.

How would CARTOSAT-I add to Earth Observation (EO) initiatives of India?
The tenth plan of EO talks about developing a Natural Resources Repository (NRR) that can distribute data through the NNRMS and the development of Village Resource Centres (VRC), besides the ambitious Meteorology and Oceanography Programme. Natural Resources Census (NRC), Large Scale Mapping (LSM), and Cadastral Geo-referencing to Satellite data are some of the ongoing projects under NRR, which will get a major fillip from the CARTOSAT-I.

How do you think CARTOSAT-1 can be of relevance to the National Mapping Agencies (NMAs) of India and beyond?
I suppose, it is the NMAs that can stand to gain the most from the CARTOSAT-1 in the longer run. As I said earlier, it carries two state-of-the-art Panchromatic (PAN) cameras that take black and white stereoscopic pictures of the earth in the visible region of the electromagnetic spectrum with 2.5 metre spatial resolution and a swath of 30 kms. With a B/H ratio of around 0.6, we can expect to get a height accuracy of around 4 metres, and a contour mapping capability of around 10 metres. All of the these key features can be of enormous value to any mapping agency. Definitely, the NMAs of this region shall be at an advantage. The sector of land management can become highly organized with detailed terrain based cadastral maps being developed for the entire nation.

In spite of being a leader in Remote Sensing, India still finds its own market limited. What are your observations?
I beg to differ with you on this point. I am aware of the enormous market India has for satellite remote sensing data. I have seen it for myself as National remote Sensing Agency (NRSA) has doubled the data sales in the last two years with the last year sales touching a record of Rs 35 crores (almost US $ 8 million). Keep in mind; this has come from the business largely from within the country. The user base in India is vast and has a huge potential to grow further. With the development of the advanced satellites like CARTOSAT-1 and the ever-increasing product range, the users can now be in a better position of getting the best data. Of course, training remains an issue and it will take some time before the culture of utilizing these tools sets in. There is also a question of developing open source software solutions which are cheaper for the end users.

Academia and industry have to come forward to cooperate in making these tools easily understandable and acceptable. For penetration of the products, appropriate policy formulation, both in the context of data and map, is important. You are aware of the ongoing developments in regard to technology advances as well as the responses from the policy makers, and I am sure, we will have a balanced position ultimately benefiting the community at large.