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India Launches World's First Stereo Imaging Satellite
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."
But HIFI stereo, which means it has the highest level of fidelity available. It also sports an 8-track.
...will be off-shored to China.
Religion is for people afraid of going to hell.
do the cameras have to be to get a proper parallax?
Uh, can't they already determine heights to high degree of accuracy with GPS or other radio wave methods? How would a picture be more accurate?
I don't get. If it's not a geosync, then it's going to be moving, so they could just use 2 images from a few seconds apart to get the required images. No?
I'm going to assume the satellite designers knew what they were doing and there is some good reason for this.
:-), I'm looking for something a little more informed.)
That said, given the resolution with which we know the position of a given satellite, and the low resolution of the source image in this case, what advantage does using two cameras give you, vs. taking one camera and snapping two pictures in quick succession?
Maybe they can't be snapped quickly enough? But then, you'd think the larger parallax would be helpful, not harmful.) I know consumer cameras have the basic tech now to take a snapshot of the CCD state and process it later, that tech ought to scale right with the CCD resolution, whatever it is.
Maybe this is so you can choose the parallax direction, instead of the orbit forcing your choice? Does the image processing need the parallax to show up in some particular direction relative to the light source to work?
Honest questions; knowledgeable answers appreciated. (As you can see, I can talk out of my ass too
Weather Radar on birds with ISAR can do this.
0 49193.Ph.r.html
http://www.madsci.org/posts/archives/2004-09/1094
I've exchanged email with NOAA about hurricane photos and have been told that some of them are inface ISAR radar images that have been colored.
The blurb there for the story sounds like a Press Release there from Mr Nair, chairman of the Bangalore-based Indian Space Research Organisation (Isro).
This is just supposition, based on the fact that two cameras on a satellite would not be far enough apart to generate parallax.
Share. Until it becomes uncomfortable. Or at least a little.
I knew they were big into offshoring but...
Over the summer and last semester I worked in a nano-satellite lab at ASU. The most recent satellite of ours that was launched was Three Corner Sat and one of its primary mission objective was sterio imaging.
g e=3CS
http://threecornersat.jpl.nasa.gov/
http://nasa.asu.edu/
https://spacegrant.colorado.edu/tiki-index.php?pa
Unfortunately, the two of our satellites that got launched were released at 50,000 km instead of 100,000 km so they burnt up before they could power up.
http://www.spacetoday.net/Summary/2737
-- James
Any truth to the rumor that they're going to oursource their call center to a US firm?
I'm kidding!
"If god did not exist, it would be necessary to invent him" --Voltaire
... hopefully with Dolby!
--- Attorneys Assisting Citizen-Soldiers & Families -
See who keeps sneaking their $&^%@ trash into your can.
At 2.5 meter resolution? You must have some FAT neighbors.
See what I've been reading.
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.
Please help metamoderate.
If they could only get a little better resolution, I can imagine they could pull in some cash by taking pictures of nude beaches. You would think that by now the first thought with new tech would be, "how can I use this for porn?"
I Am My Own Worst Enemy
Due to spacecraft (or aircraft) motion, stereo pairs are generated along the flightpath if sequential images overlap. In many systems, each image n generates overlap with both image n+1 and n+2. Given the ability to launch two cameras, why not launch a single camera with more capabilities? Another minor, and common, error is that the Cartosat-1 has a 2.5m pixel on its CCD, which does not transalate into a 2.5m "resolution." CCD resolution corresponds to Ground Sampled Distance (GSD), or the amount of ground sampled on one pixel. Ground resolved distance, (GRD), measures the highest frequency visible in the image and is what we normally think of as "resolution." As a result, for electro optical systems, GRD = 2 x GSD.
Perhaps I'm not understanding how the submitter is using the term "non-military", and not to wave Uncle Sam's flag too much, but offhand I can think of more than six US RS platforms/sensors:
EOS/Terra/MODIS http://modis.gsfc.nasa.gov/
Landsat ETM+ http://landsat.gsfc.nasa.gov/
Landsat MSS (yes still going)
AVHRR http://daac.gsfc.nasa.gov/data/dataset/AVHRR/
GOES http://www.goes.noaa.gov/
ASTER http://asterweb.jpl.nasa.gov/
Not to mention US based commercial satellites:
IKONOS http://www.spaceimaging.com/
Quickbird URL:http://www.digitalglobe.com/
Getting proper parallax from 620 km is a bit tricky. The cameras would need to be many km apart to get good stereo (31 km camera baseline is equivalent to the parallax that human eyes have at 1 meter).
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.
Two wrongs don't make a right, but three lefts do.
This isn't the first stereographic satellite that's accessible to the general public; that would be MISR - NASA's Multi-angle Imaging Spectroradiometer, built by JPL, with nine cameras pointed in different directions along its direction of travel in polar orbit, ranging from nadir (straight down) to 70 degrees in either direction. Compared to India's new high-resolution satellite, MISR seems very low resolution - 275 meters per pixel - however, it covers the entire surface of the Earth every few days and all of the data is available for free at this resolution, while India's satellite is "targeting"; it only images a particular area when it is programmed to do so. MISR is used primarily to study clouds and aerosols.
To see some 3-D images taken by MISR or some animations of its 9 cameras' views of different scenes, check out their gallery.
Mmm, check out that white pixel laying on the sand colored pixel. Boy, would I like to anti-alias her! Assuming it is a her, and not a surfboard or a trashbag or something. Eh, who am I kidding? I'm not that picky.
1. The Indian economy happens to be the 12th largest in terms of GDP and 4th largest when adjusted for PPP (Purchasing Power Parity). 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) pursued a pretty widespread (and largely non-military space program) since the 60's. From this relevant Wikipedia article:
# 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.
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
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.)
Live Long and Prosper - Thanks Leonard. You are missed.
Get cool 3D images of Grand Canyon, Yosemite, Everest, Uluru, etc.
Don't get too excited. The process of extracting 3d depth from a pair of 2d pictures is shockingly more difficult than one would initially expect. Given the 2d positions of the same point in both cameras, it is trvial to find the 3d depth, but in practice the problem of finding the corresponding points is extremely difficult. (It is called the 'correspondence problem' and can justifiably be called the holy grail of the field of Computer Vision.) For those who are truly interested, you can actually see how most of the current state of the art stereo algorithms run on a few (easy) stereo pairs here.
I do not have any arms or legs.
And a nitpick which will hopefully bring this post back on topic - the average literacy you mentioned is wrong. It is 64.8% according to the 2001 census. The number you gave was for 1991. 14 years can make a lot of difference in a country like India, even given its huge population.
The same rocket launch also put into place ham satellite for use in South Asia. There are other satellites available for personal use (AMSAT has several, including (Echo 51) but VUSat is focused on use from India and South Asia.
India doesnt receive much direct aid from the US . Indian poor do receive a large amount of money from US based evangelical groups trying to promote Christianity in India (pretty successfully too Already 2 Indian states have become Christian Majority over the last 50 years )
India keeps losing it best people to the US but now slowly more and more people are staying back and using their brains to run ISRO and DAE (department of Atomic Energy) instead of enriching the shareholders of IBM and Microsoft.
There is great emphasis on tech in India . Engineers are much more respected in society than doctors or lawyers in contrast to the US so a lot of the top brains go to Engineering.
**Life is too short to be serious**
Yes, but there are advantages to doing this via satellite as well. For example, repeat passes allow observation of subtle changes in topography due to things like subsidence from withdrawal of water or petroleum, glacier movement, tectonic and volcanic activity, etc. Basically, think about all of the applications of SAR (synthetic aperture radar, for non-remote sensers) Interferometry. There are also LIDAR satellites such as IceSAT that observe elevations with great precision along transects. There are actually quite a number of satellites up there with the capability of doing things similar to this, but generally not at this spatial resolution (2.5 m). I'm involved with a group proposing a satellite to NASA that would be used to obverve changes in water heights on floodplains and in rivers, allowing observation of ungauged rivers in remote regions as well as helping to get a handle on discharge from rivers (such as the Amazon) which are impossible to gauge along much of their length.
I'm not saying you're wrong about Pakistan though, just that you're wrong about archived maps of India...
[o]_O