Note: I wrote this on my earlier blog hosted as https://parallelspirals.blogspot.com. I recovered the text from the WayBack Machine. This post appeared on March 01, 2011. I’m trying to collect here again all my old writings spread on various blogs.
I went to the Tata Institute of Fundamental Research (TIFR) on Monday to hear the National Science Day Public Lecture organised by TIFR and the TIFR Alumni Association. The talk was delivered by Ragunath Navalgund, Director, Space Applications Center, Indian Space Research Organisation (ISRO).
At the welcoming address, the TIFR Director gave us a brief about how the day, February 28 had come to being celebrated as National Science Day. He said it was the day that C V Raman had submitted the manuscript which talked about the Raman Effect for the first time. The discovery of the Effect gave Raman a Nobel Prize and is still one of the most renowned discovery by an Indian scientist. He said further that Raman used to give public talks on science in a manner which was understandable to the general public. This is perhaps one of the first examples of science outreach by an Indian scientist. The day was later adopted by the Government of India to be called National Science Day. At TIFR, the day was celebrated by lectures from prominent alumni members.
R Navalgund then gave the Director a copy of the lunar atlas with pictures from the Chandrayaan-I spacecraft. I was thinking of nicking it!
Navalgund began his talk titled, “Remote Sensing of the Earth and the Moon” by talking about remote sensing in general. He defined it and explained how it was different from “seeing with our eyes”. He explained the difference as being sensing in various wavelengths of the electromagnetic spectrum other than just visible light like our eyes. The results are in the form of data sets which are then converted into images. He explained that remote sensing was done from various platforms – low-Earth orbit and geo-stationary orbits depending on their applications.
He moved on to various types of sensing – active and passive and then explained the various techniques of remote sensing. He showed the push-broom type, the pixel-by-pixel type, the synthetic aperture radar and the hyperspectral imaging.
He talked about how various parts of the electromagnetic spectrum could be studied in individual bands interacted with objects on the ground and how these could help in providing useful information. As an example, he talked about studying leaves with red light and near infra red light to understand if leaves were healthy or mature. This data helped in providing the Government a plausible estimate of the healthy plants in the country well before the harvesting period. Similar studies were done in various spectrum for hydrology, cryosphere, forest cover, atmosphere and oceans to provide similar information. Information involved ground water levels, forest covers, smogs, possible fishing zones, crop health prediction and yield.
He then moved on to the remote sensing of the Moon. He showed the various types of craters and features like the central peaks of craters and impact melts. He also showed pictures from the recently discovered lava tube.
The interesting points though came out in the question and answer session. Answering questions by students from Kendriya Vidyalaya, Navalgund came out with quite a few interesting points that were unknown. Speaking on India’s participation in the International Space Station (ISS), he said that there was an informal agreement on the possibility of India conducting experiments on the ISS. He said that the discussions were currently on in this regard. The experiments, he said, would relate to the study of green house gases. He said Indian institutions would have to provide a proposal for these experiments and some would also come from within ISRO. Answering another question on the Human Spaceflight Programme, he said that all the designs, approvals and paper work was done. The Programme had got an in-principle nod from the Indian cabinet. Discussions were currently on as to how to implement the programme. The two ideas included doing the testing in a single shot or testing the elements individually as done with Space Re-entry Experiment (SRE). He said the programme was in this phase currently. Answering a question I posed, he shocked me by saying that data from the Terrain Mapping Camera (TMC) and Hyper Spectral Imager (HySI) have been made available online. Srinivas found the website for me, it is here. Navalgund explained that the images were released only after 1 year to aid the investigations done by principal investigators who were the primary users of the data. He said that NASA had separately released the data from the Moon Mineralogy Mapper (M3). On Mars, Navalgund said that the plans were currently in drawing board phase and currently, India only had capability to do a flyby or orbiter programme indigenously.
My friend, Srinivas asked the question about why India’s CHACE instrument was not given the credit for the lunar water discovery as much as M3 or even Mini-SAR. Navalgund replied that the instrument did have a short operation span and did find spectrum peaks for water, carbon dioxide and other elements. He said a lot of time was spent on calibrating the data properly. This was a long drawn process which possibly led to the CHACE losing out on the credit for the water discovery.
I also met a member of the newly joined Google Lunar X Prize team, Team Indus at the lecture.
Parallel Spirals 