RISAT/CARTOSAT : India's Intelligence Satellites in Orbit

[warriorextreme]

what the hell is our satellite doing over africa

full image http://i50.tinypic.com/sfuwwx.png

Basic question: If the satellite is in Geo Synchronous position then does it always be over a particular place (Ex. India)?

which regions is RISAT going to be over?

what is geo-synchronous satellite and how does it matter educate me please

a geosynchronous satellite is launched into geosynchronous orbit...geosyn sats always remain at one position with respect to earth...this is because rotational speed of earth and this satellites is same(hence the orbit is called as geosynchronous orbit)

RISAT-1 is not a geosynchronous satellite hence it travels everywhere

our communication satellites are geosynchronous..

 

[Ray]

[video]http://www.ehow.com/video_4756359_what-geosynchronous-satellite.html[/video]

Geosynchronous Satellite


What Is a Geosynchronous Satellite?
By Steve Jones, eHow Presenter

A geosynchronous satellite is a satellite with an orbital time of 24 hours, and they are stationary at the same point on earth once a day.

Find out how a geostationary orbit will allow a geosynchronous satellite to stay above the same point with help from a science teacher in this free video on physical science (as link above)

Video Transcript

Hi, I'm Steve Jones. I'm going to tell you a little about Geosynchronous Satellites. Now the point about satellites is that these are objects, all satellites is the description of objects in orbits round other objects. So the moon is a satellite of the earth. But we have artificial satellites which are sent up in circular orbits round the earth and as you can imagine, you can't really have something in orbit round a pole. It has to be in a great circle orbit in this way. As you can see the green and the red ones are in a great circle orbit. Now the first we have to make sure of if we want to Geosynchronous is to make sure that the orbital time is 24 hours, the same time as it takes for the earth to rotate. So don't forget the earth is rotating at this time. So the earth is rotating and the satellites are going round the earth, totally independently, they're not affected by the earth 'cause the, they're above the atmosphere. So we've got satellites above the atmosphere rotating in their own independent orbit influence only by the earth's gravity. Their orbital time 24 hours means that they go around once in the same time that the earth takes to go around. Now therefore you've got two basic different times. You've got Geostationary orbit; now this can only occur in the equator; that a satellite above the equator, of course it's a jet great circle and therefore, that satellite, if it rotates once a day, then it will always be over the same point in on the earth. So that satellite will actually be always up there. And this is extremely useful of course. But there are other types of Geosynchronous orbits. For example, if you look at the point A here, this orbit means that this satellite is always visible at point A for quite a long time during the day. Obviously, right from here, right to there, for a quarter of the orbit of this satellite, it's going to be visible at A. This is Geosynchronous, that is you'll be able to look onto it, but at the same time each day, it is going to be there. Now by having a combination of different satellites, you can ensure that there is always one satellite in a series to log onto at any one time. It won't be much good having a TV channel where, okay, only between seven and eight in the evening could you get the satellite to work. You want a satellite working overtime and therefore, there is a set of satellites together which provide you with this service. So Geosynchronous Satellites are ones with an orbital time of 24 hours and are stationary at the same part or at the same point on the earth, once a day unless they are a Geostationary orbit, which means that around the equator, in which case then, they can be above the same point at all times. So that describes a Geosynchronous Satellite.


Read more: Video: What Is a Geosynchronous Satellite? | eHow.com http://www.ehow.com/video_4756359_what-geosynchronous-satellite.html#ixzz1udEC3yzX

 

[Ray]

The RISAT-1, however, is the country's second radar imaging satellite. India already operates the Israeli-built RISAT-2, which was launched in April 2009 and appears to have been quickly procured to meet security requirements.

 

[utubekhiladi]

drdo, said this satellite is not developed for spying but can be used for spying. so can one explain how can it be used for spying?

 

[utubekhiladi]

very useful information

A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day traces out a path in the sky that is typically some form of analemma. A special case of geosynchronous satellite is the geostationary satellite, which has a geostationary orbit – a circular geosynchronous orbit directly above the Earth's equator. Another type of geosynchronous orbit used by satellites is the Tundra elliptical orbit.

Geosynchronous satellites have the advantage of remaining permanently in the same area of the sky, as viewed from a particular location on Earth, and so permanently within view of a given ground station. Geostationary satellites have the special property of remaining permanently fixed in exactly the same position in the sky, meaning that ground-based antennas do not need to track them but can remain fixed in one direction. Such satellites are often used for communication purposes; a geosynchronous network is a communication network based on communication with or through geosynchronous satellites....

If a geosynchronous satellite's orbit is not exactly aligned with the Earth's equator, the orbit is known as an inclined orbit. It will appear (when viewed by someone on the ground) to oscillate daily around a fixed point. As the angle between the orbit and the equator decreases, the magnitude of this oscillation becomes smaller; when the orbit lies entirely over the equator, assuming a circular orbit, the satellite remains stationary relative to the Earth's surface – it is said to be geostationary.

wiki
Geosynchronous satellite - Wikipedia, the free encyclopedia

Geostationary Satellite

a geosynchronous satellite is launched into geosynchronous orbit...geosyn sats always remain at one position with respect to earth...this is because rotational speed of earth and this satellites is same(hence the orbit is called as geosynchronous orbit)

RISAT-1 is not a geosynchronous satellite hence it travels everywhere

our communication satellites are geosynchronous..

[video]http://www.ehow.com/video_4756359_what-geosynchronous-satellite.html[/video]

Geosynchronous Satellite


What Is a Geosynchronous Satellite?
By Steve Jones, eHow Presenter

A geosynchronous satellite is a satellite with an orbital time of 24 hours, and they are stationary at the same point on earth once a day.

Find out how a geostationary orbit will allow a geosynchronous satellite to stay above the same point with help from a science teacher in this free video on physical science (as link above)

Video Transcript

Hi, I'm Steve Jones. I'm going to tell you a little about Geosynchronous Satellites. Now the point about satellites is that these are objects, all satellites is the description of objects in orbits round other objects. So the moon is a satellite of the earth. But we have artificial satellites which are sent up in circular orbits round the earth and as you can imagine, you can't really have something in orbit round a pole. It has to be in a great circle orbit in this way. As you can see the green and the red ones are in a great circle orbit. Now the first we have to make sure of if we want to Geosynchronous is to make sure that the orbital time is 24 hours, the same time as it takes for the earth to rotate. So don't forget the earth is rotating at this time. So the earth is rotating and the satellites are going round the earth, totally independently, they're not affected by the earth 'cause the, they're above the atmosphere. So we've got satellites above the atmosphere rotating in their own independent orbit influence only by the earth's gravity. Their orbital time 24 hours means that they go around once in the same time that the earth takes to go around. Now therefore you've got two basic different times. You've got Geostationary orbit; now this can only occur in the equator; that a satellite above the equator, of course it's a jet great circle and therefore, that satellite, if it rotates once a day, then it will always be over the same point in on the earth. So that satellite will actually be always up there. And this is extremely useful of course. But there are other types of Geosynchronous orbits. For example, if you look at the point A here, this orbit means that this satellite is always visible at point A for quite a long time during the day. Obviously, right from here, right to there, for a quarter of the orbit of this satellite, it's going to be visible at A. This is Geosynchronous, that is you'll be able to look onto it, but at the same time each day, it is going to be there. Now by having a combination of different satellites, you can ensure that there is always one satellite in a series to log onto at any one time. It won't be much good having a TV channel where, okay, only between seven and eight in the evening could you get the satellite to work. You want a satellite working overtime and therefore, there is a set of satellites together which provide you with this service. So Geosynchronous Satellites are ones with an orbital time of 24 hours and are stationary at the same part or at the same point on the earth, once a day unless they are a Geostationary orbit, which means that around the equator, in which case then, they can be above the same point at all times. So that describes a Geosynchronous Satellite.


Read more: Video: What Is a Geosynchronous Satellite? | eHow.com Video: What Is a Geosynchronous Satellite? | eHow.com

The RISAT-1, however, is the country's second radar imaging satellite. India already operates the Israeli-built RISAT-2, which was launched in April 2009 and appears to have been quickly procured to meet security requirements.

 

[Ray]

Spy satellites are basically recce satellites aimed specifically for military intelligence.

They could be used for high resolution photography, or signal intelligence (eavesdropping etc)

 

[Ray]

What is a keyhole satellite and what can it really spy on?

The code named Kennan "Keyhole-class" (KH) reconnaissance satellites have been orbiting the Earth for more than 30 years. They are typically used to take overhead photos for military missions. The big question for a lot of people is: "What can they see?"

A KH-12 is a $1 billion satellite that resembles the Hubble Space Telescope, except it is looking at our planet. For security reasons, there are no published orbit schedules for the imagery spacecraft. They are supplemented by the 15-ton Lacrosse-class radar-imaging satellites.

You can think of a KH satellite as a gigantic orbiting digital camera with an incredibly huge lens on it. Optical image reconnaissance satellites use a charge coupled device (CCD) to gather images that make up a digital photograph for transmission back to Earth from an altitude of about 200 miles. Since the satellites are in orbit, they cannot hover over a given area or provide real-time video of a single location.

The satellites are often placed into various secret orbits by NASA space shuttles or Titan 4 rockets and managed by the National Reconnaissance Office (NRO), headquartered in Chantilly, Va. Digital images from the satellites are analyzed, manipulated and combined by powerful computers at the National Geospatial-Intelligence Agency (NGA).

The black and white images are used by the military and civilian communities. Many of the details about this class of satellites remain classified, but it is known that there are several of these overhead at any given time. They have an imaging resolution of 5-6 inches, which means they can see something 5 inches or larger on the ground. These satellites probably can't read your house number, but they can tell whether there is a bike parked in your driveway.

Corona satellites, the first to do mapping of the Earth from space, had an imaging resolution of 6 feet. Those satellites were built by Lockheed Martin under contract to the CIA and the U.S. Air Force from 1960 to 1972 and were reportedly launched more than 100 times.

Mapping analysts can use satellite data to create 3-D images of land formations and structures on the ground. These images can then go to the negotiating table as countries try to end a war. Or, as in the case of the television show, the images can prove that the official word from a foreign government about some activity on the ground is not true. The same technology is also used to visualize potential escape routes for criminal activity. One was once reportedly used to observe the underbelly of an orbiting space shuttle for missing ceramic tiles, needed for re-entry.

In the United States, Vandenberg Air Force Base in California has been the primary site for the launch of many surveillance satellites during the Cold War and to the present. Some early satellites had capsules aboard to return film canisters to the Earth. The canisters were snatched in the air by Air Force crews over the Pacific Ocean. Since 1958 the special satellites were made by Lockheed Martin, and more recently Boeing has the contract with the National Reconnaissance Office.

HowStuffWorks "What is a keyhole satellite and what can it really spy on?"

 

[agentperry]

risat makes reourcesat looks shit

 

[Ray]

An interesting site on satellites with animation.

How does a satellite's job dictate its orbit?

Scijinks :: How does a satellite's job dictate its orbit?

 

[sayareakd]

our present satellite is orbiting satellite, it takes many rounds of the earth, thus covring many parts of earth during a day. So with this satellite we can keep watch over Iraq and Afaganistan a part from China and Pakistan. With radar it can take images at night and can see through clouds. Since it use radar i think it has option to see only metal objects, which will be useful for for seeing hidden objects and subs. How deep it can see subs in sea is million $$$ question.

 

[Ray]

Inclination entangled with other orbital elements

An important subtlety of performing an inclination change is that Keplerian orbital inclination is defined by the angle between ecliptic North and the vector normal to the orbit plane, (i.e. the angular momentum vector). This means that inclination is always positive and is entangled with other orbital elements primarily the argument of periapsis which is in turn connected to the longitude of the ascending node. This can result in two very different orbits with precisely the same inclination.


More at:
Orbital inclination change - Wikipedia, the free encyclopedia

 

[Ray]

This is an important aspect.

Adjusting While in Orbit

Also important in the orbit of a satellite is the adjusting of it while in orbit. This is done through the use of rockets. Throughout the life of the satellite the orbit and attitude, the direction it points, must be adjusted. Generally they have on-board rockets for this purpose. Sometimes the rocket may be fired to accelerate the satellite and move it to a higher orbit or to decelerate the satellite and move it to a lower orbit. It can also be changed by firing the rocket to the side which changes the direction the satellite points. With the use of these special rockets the satellite can be moved at any time to any necessary position for any reason or another. The rockets help keep the satellite on its course without the possibility of it losing altitude or falling right out of the orbit in which it was in. A satellite's position has much to do with the time. For example, a satellite located 22,300 miles above the Earth's surface which is said to be synchronous, takes exactly 24 hours to orbit around the Earth once. This is said to be synchronous because it is synchronized with the Earth's rotation. Not all orbits are said to be synchronous and the time required for a satellite to complete one revolution around the Earth depends on its altitude. The laws that govern a satellite in orbit are the same laws that govern the motion of natural satellites and it travels around the planet in a nearly circular orbit when it reaches the 100 mile mark above the Earth's surface (Compton's Encyclopedia).
Satellites in Orbit

 

[trackwhack]

how can we use this satellite/image for spying purposes.

They will never post a picture for the public with max resolution where it can identify 1 meter wide objects.

 

[anoop_mig25]

nice and informative thread . thanks everbody for posting information in it

 

[LETHALFORCE]

India Plans To Launch First Military Satellite

India Plans To Launch First Military Satellite

Indian forces are ready to launch the nation's first military satellite, the Times of India reported on Monday.

The satellite is designed for naval intelligence and communications, according to the newspaper, which added that the device is ready and its launch is expected in about a month, quoting an unnamed government source.

The satellite, which will be on orbit over the Indian Ocean, will transfer high speed data, and link all Indian naval ships, submarines, airplanes and control centers on the shore into a single information network.

 

[trackwhack]

Re: India Plans To Launch First Military Satellite

Everytime they launch a spy satellite, they say its the first one. Whats the deal?

Oh wait this is a communication sat right?

 

[LETHALFORCE]

Re: India Plans To Launch First Military Satellite

Everytime they launch a spy satellite, they say its the first one. Whats the deal?

Oh wait this is a communication sat right?

Cartsosat and Risat,Oceansat can be considered military satellites launched earlier.

 

[LETHALFORCE]

GISAT - Geo-Imaging Satellite under developemt by ISRO

The Hindu : Today's Paper / NATIONAL : A special 'eye' up in the sky to constantly watch over the country

The satellite will be in geo-stationary orbit, always looking over the same region
Imagine an eye far up in the sky that is constantly trained on the country and alerts authorities 36,000 km below of trouble spots, natural disasters, floods and forest fires within, say, five minutes of the event. More importantly it will also keep a watch over our sensitive borders.

The design for one such special 'eye' — called the Geo-Imaging Satellite or GISAT — is taking shape at the Space Applications Centre, Ahmedabad. With a recent approval and Rs. 50-crore allocation this financial year for preliminary work, GISAT should be a reality in a couple of years. The sub-1,000-kg satellite will be put in space by a PSLV rocket.

Real time imagery

Previous remote-sensing satellites sent up by the Indian Space Research Organisation also do the same job. However, they go over from pole to pole at a distance of 600-900 km from the ground, view a particular area for barely ten minutes and do not visit the same place for the next one, three or five days. GISAT, on the other hand, will be fixed in a geo-stationary orbit, always looking over the same region and synchronised to the Earth's 24-hour rotation.

A 2012-13 Budget grants document for the Department of Space describes GISAT as a "multi-spectral, multi-resolution advanced remote sensing satellite." Its nearly real-time imagery can speed up authorities' response to calamities and troubles to almost immediately, Mr. Tapan Misra, Deputy Director at SAC's Microwave Remote Sensors Area, told The Hindu .

A marvel

Its electronically steerable camera can 'see' as small as a 60-metre area from its height of 36,000 km. It will be a marvel up there compared to what ISRO's low-flying Earth observation satellites can do with their fine resolutions of 2 m, 1m and even less than one metre, Mr. Misra, who was here for the ISRO-CII-sponsored conference, World Space Biz 2012, said.

"A single early-warning satellite, giving you constant, complete coverage of the country, is unique," according to Dr. V.Jayaraman, former Director at ISRO's Hyderabad-based National Remote Sensing Centre. And a world first, he said.

It will be equivalent to putting a Cartosat — another of ISRO's advanced 'eyes' but in the lower sky — at long distance.

It would complement the advanced meteorology and remote-sensing satellite, Insat-3D, due to be launched in December this year, said Dr. Jayaraman, who was earlier Director, Earth Observation, ISRO.

GISAT, Mr. Misra said, will be built on ISRO's technologies that went into Cartosat and Radar Imaging Satellite (RISAT-1) — "both of which were big technology leaps for the country."


The sub-1,000-kg satellite will be put in space by a PSLV rocket

Its camera can 'see' as small as a 60-metre area from its height of 36,000 km

 

[LETHALFORCE]

re: GISAT - Geo-Imaging Satellite under developemt by ISRO

The Calibre Geo-Imaging Satellite (GISAT) » The Calibre


The Calibre Geo-Imaging Satellite (GISAT)

 

[LETHALFORCE]

re: GISAT - Geo-Imaging Satellite under developemt by ISRO

India to launch satellite to monitor border - Economic Times

India to launch satellite to monitor border

NEW DELHI: India proposes to launch Radar Imaging Satellite (Risat-1) with cloud penetrating capability for imaging various parts of the country, including border areas, the Lok Sabha was informed Wednesday.

Replying to a question, Minister of State in the Prime Minister's Office V. Narayanasamy said that Indian Space Research Organisation (ISRO) is also planning to launch a geo-imaging satellite (Gisat) to provide near real time pictures of large areas of the country.

"The Gisat will provide the pictures of the areas of interest on near real time basis. That is, selected sector-wise imaging every five minutes and entire Indian landmass every 30 minutes at 50 metre spatial resolution," he said.

With 5.47 a.m. Thursday set for the blast-off of Risat-1 into space, the Indian space agency is fuelling the rocket's second stage with liquid propellant.

"The major activity today (Wednesday) is the filling up of the liquid fuel in the rocket's second stage. The countdown is progressing well and every system in the rocket is normal," a source in the ISRO told IANS in Chennai.

The indigenous Risat-1 with a life span of five years would be used for disaster prediction and agriculture forestry, and the high resolution pictures and microwave imaging could also be used for defence purposes.

The rocket is ready to escape the Earth's gravity to put India's heaviest microwave satellite, Risat-1, weighing 1,858 kg at an altitude of 480 km at an inclination of 97.552 degree, ISRO sources said.