India Launches World's First Stereo Imaging Satellite 339
sgups writes "India will tomorrow inaugurate a new launch pad at its Satish Dhawan space port near Chennai, on the south-east coast, by putting the world's first stereographic mapping satellite into orbit.
The most innovative feature of the 1.6-tonne Cartosat-1 is its pair of cameras, which will give stereo images of the earth's surface that can distinguish features down to 2.5 metres across. They will directly generate three-dimensional maps that have until now been achievable only indirectly, by combining data from a large number of satellite passes over the same place.
"Such a stereographic imaging system does not exist in the civil sector anywhere else," says Mr Nair, chairman of the Bangalore-based Indian Space Research Organisation (Isro). "It will give information about heights that will be very useful in applications such as planning power lines."
Cartosat-1 will join what is already the world's largest cluster of non-military remote sensing satellites. Six Indian spacecraft are already observing the earth with a wide range of instruments."
Re:I don't get (Score:4, Insightful)
power lines? Riiiight. (Score:4, Insightful)
Um...right. Like decades if not centuries of maps can't help there. Besides, I would think that in a country as large as India, they'd be focusing on localized power generation.
Sorry, but this sounds like a really lame excuse for lobbing a satellite up there to spy on Pakistan, with a happy-go-lucky PR spin so the average citizen thinks "oh, another satellite that will be useful!" Yessir, routing power lines.
Not like the US hasn't done the same thing- the majority of shuttle missions were for either admitted, or "disguised-as-scientific-experimentation" military satellites.
Parallax by pointing (Score:5, Insightful)
Instead, I suspect that the parallax is achieved by having two cameras that point slightly different angles. One points down and forward along the track of the satellite, the other points down and backward. Thus, as the satellite passes overhead, the same spot on the ground is seen by the two cameras in succession from different parts of the orbit.
For purposes of get topo data on fixed objects, its more than adequate. Given that the satellite is moving about 8 km/sec, it traverses the needed baseline for stereo in only a few seconds. This is not enough time for the scene to have changed that much.
Re:Not the distance between the cameras (Score:2, Insightful)
Since you asked for a clarification.... (Score:5, Insightful)
1. The Indian economy [wikipedia.org] happens to be the 12th largest in terms of GDP and 4th largest when adjusted for PPP (Purchasing Power Parity [wikipedia.org]). I quote from the Wikipedia article:
With a GDP of 568 billion (B$) ($3.096 trillion (T$) at PPP) India has the world's 12th largest economy (and the 4th largest when adjusted for PPP). However, the large population means that per capita income is quite low. In 2003 the World Bank ranked India 143rd in PPP per capita income and 160th in real terms, among 208 countries and territories.
2. India has (through the Indian Space Research Organization [isro.org]) pursued a pretty widespread (and largely non-military space program) since the 60's. From this relevant Wikipedia article: [wikipedia.org]
# 1962: Indian National Committee for Space Research (INCOSPAR); formed by the Department of Atomic Energy, and work on establishing Thumba Equatorial Rocket Launching Station (TERLS) near Trivandrum began.
# 1963: First sounding rocket launched from TERLS (November 21, 1963).
# 1965: Space Science & Technology Centre (SSTC) established in Thumba.
# 1967: Satellite Telecommunication Earth Station set up at Ahmedabad.
# 1972: Space Commission and Department of Space set up.
# 1975: First Indian Satellite, Aryabhatta, launched (April 19, 1975).
It's also fruitful to note that India was a British colony till 1947. IMHO, starting a space program in about 1.5 decades after gaining independence is a laudable achievement. The major problem which India faces today is it's large population, which pretty much negates all the economic advances, and causes it's perception as a "thirld world country" to continue.
It is also worth noting that India seems to be spending substantial amounts of money to improve it's people's lot and advancing education, science and research, rather than spending it instead on aggressive military tactics, which seems to be the trend nowadays. If you read up the history of the nation, you'll see that it's one of the few countries that has never pursued invasion/colonialism, and has instead been frequently invaded by conquerers (Mughals, British, etc) who looted the wealth of a formerly rich region and left it in a state that it's trying to dig itself out of now.
PS: Posted this because I perceived a derogatory slant in the Parent's use of the term "third world country". I find the practice of using wealth to rank nations (especially so when used to diss poor nations) quite abnoxious. I have nothing against using the term in a scientific/neutral sense.
Re:India Can't Afford This (Score:3, Insightful)
I'm going to act as if the poster was sincere and not a troll, therefore deserving of a thoughtful answer.
Every government is faced with the challenge of balancing the short term needs of the impoverished with the long term obligation to develop the national infrastructure and long term high paying jobs and therefore wealth of their economy.
In the US from the 1960's onward, there were cries by some that the billions of dollars spent on our space program should have been spent on our poor. While we don't have the numbers of poor that are in India, a visit to American rural areas like Appalachia or any number of American Indian reservations or a visit to American inner city areas will tell you that we still have our own millions of people living in violent areas, without adequate food, medical care, education, or hope for improvement in these areas.
Even so, others will argue that much of American wealth created and shared by most of the population was helped by research in space and other military programs. (The reason we started our program was to maintain parity with the former Soviet Union.) If spin-offs from the Indian investments in space translate to private sector jobs, then an argument may be made that it has long term value.
If there is anything the Ronald Reagan taught us Americans (and no, I was NOT a big fan of Reagan's in many areas), it was that symbols, even costly symbols, can motivate millions to take actions toward better goals. (He followed Jimmy Carter. A man whose intelligence, sincerity and battles for human rights, were overshadowed during his presidency by American feelings of "malaise" and general helplessness felt during the hostage crisis, oil shortages, and resulting recession.)
Re:All this... (Score:3, Insightful)
I had enough of "but there are starving people there" comments about India. India is a developed nation as far as intellectual capital is concerned. If the Indian government completely ignored this segment of the population, they would simply emigrate.
Re:Heights? (Score:3, Insightful)
Yes.
How would a picture be more accurate?
Well, among the most accurate topographical maps available are from the Shuttle Radar Topography [usgs.gov] mission, which gave us the entire earth at roughly 30-m resolution, with a height precision of about 16 meters.
India's new satellite has 2.5-meter resolution, and its vertical accuracy after proper stereoscopic matching would be of the same order of magnitude so clearly in this case, it is more accurate.
Plus, the SRTM mission is over. It doesn't help if you're trying to measure a new building, for example.
You could probably get more accurate with a specialized radar or lidar instrument, but those give you point measurements, not images. And passive imaging requires far less power. So, there are lots of advantages to stereo images.
Re:All this... (Score:3, Insightful)
Very true, although I think you are missing my point. I was not lamenting the fact that India is spending money on rockets instead of rice, I was amazed that they could do it at all from a budgetary aspect. Space programs are fantastically expensive. I would imagine it might be politically difficult to get funding for such a program precisely because of the large segments of illiterates, most of which (by definition) contribute almost nothing in taxes but consume a disproportionate amount of state-run services (healthcare, welfare, etc.)
After all, we have a hard enough time getting NASA dollars approved, what with all the bleeding hearts out there screaming we need those dollars "for the CHIIILLLLLDREN!"
Re:All this... (Score:3, Insightful)
Yes, but you're forgetting the inverse of your argument. 3% of the U.S. population is 8,790,827. 48% of the Indian population is 511,233,891. That means India has almost twice the number of illiterate citizens as the U.S. has total citizens. Do not underestimate the significant drain half a million illiterates can pose on an economy. Most illiterates would be confined to agricultural or other menial-labor jobs, none of which pay very much. Low pay equals low (or no) taxes derived. And yet an illiterate individual represents the same consumption of any state-run services (such as healthcare) as a literate person would. Some would say an illiterate is a greater drain on resources simply because illiterates tend to be unable to provide for themselves. All this adds up to an economy where a significant portion of the population presents a zero-sum or net loss of per capita income.
What this does mean, however, is that whoever is productive in India is very damned productive. It also means they're probably taxed out the wazoo as well to support the lower-producing rest of the country.
the funny thing is (Score:3, Insightful)
Doesnt it feel a lil daft asking these questions over & over again?!Is a developing country only expected to feed it hungry nad look after the poverty problem.I really fail to understand that point of view.
Re:power lines? Riiiight. (Score:3, Insightful)
Re:Never pusued invasion/colonization? (Score:1, Insightful)
Re:India Can't Afford This (Score:1, Insightful)
India has a surplus of food to the extent that lack of demand is bringing the food price down to the level of hurting the farmers earnnings.
Distribution of wealth has been a major problem for india, While surplus food is rotting in some places, people in remote parts of india are suffering.
I believe the lack of precise maps was realised during the recent tsunami. I also presume Microsoft bangalore is working (god knows what can M$ deliver) in the direction of generating digital maps for precise agriculture (what ever it means).
Why would india spend on hi tech stuff, when it could have spent on poverty. I beleive it would cost india more to out source the remote sensing/mapping to developed countries. not only can it get it done cheaply, it probably may earn provinding services to other countries. (Like how Brazil realized that paying of M$, will sqeeze them dry, while they could use free-ware, albeit with some pain).
Also India learnt it the hard way of not trusting the developed nations (esp America). America has probably hurt India's ambition to achieve technology, more than any other country. India's thrive for self-reliance far exceeds the benefits of self-reliance in most of its projects.
Indian Space programe, I believe is a good success for india, especially at cost-benefit ratio. it probably has been more productive than the Chineese space program. While its other projects, esp related to defence, have been a huge drain.
I say, out source the space missions to countries like India and China, they could be done cheaper. it will decrease the tax burden for americans.
-j