ISRO joins big league in space

Posted on April 29, 2008 by Rashid Faridi

Indian space agency continues its successful run, this week it placed in orbit an Israeli spy satellite launched under a commercial contract.

This has propelled the Indian Space Research Organization or ISRO into the big league and its now well poised to enter the US$ 15 billion a year global launch market, Indian satellite images are already popular.

The commercial arm of ISRO the Antrix Corporation has meanwhile been doing brisk business with its total turnover for the last fiscal rising to Rupees 664 crores. ISRO is all set to rake in the money while travelling to Moon, Mars and Beyond.

The twenty fifth launch of a rocket from the Indian space port, a significant milestone in more ways than one.

The Polar Satellite Launch Vehicle or the PSLV placed an Israeli spy satellite TecSAR in orbit on Monday.

This is ISRO’s second fully commercial launch and even though they are not saying how much Israel paid them. Sources said that it is higher than the market rate of 20,000 dollar or 8 lakh rupees per kg. The TecSAR weighs about 300 kg.

For its first commercial launch., the 352 kg Italian satellite Agile. ISRO had charged 11 million dollars or 44 crore rupees. That too was well above the market rate.

PSLV is popular because its considered reliable and the launch site is close to the equator giving the necessary edge.

”People have realized that the PSLV is a real workhorse based on its reliability and cost effectiveness,” said Dr G Madhavan Nair, Chairman, ISRO.

Now, the Indian space agency gets 75 per cent of its business from foreign clients.

ISRO’s commercial arm, Antrix Corporation has increased its turnover by 50 per cent this fiscal, earning almost 664 crore rupees.

ISRO has contracts for launching four small satellites for Singapore, Netherlands, Canada and Germany.

And the agency has also won a contract for making two large communications satellites for European customers.

It is not just ISRO’s hardware that is in demand, but the images taken by Indian Remote sensing satellites are much in demand in the international market.

The international experts are all praise for ISRO.

”Indian Space Organisation is good, and more important than the facilities it is the quality of the engineers and scientists and the technicians. They have a great capability,” said Dr Michael Griffin, Administrator, NASA, USA to NDTV.

On being asked that whether India is ready to go moon and beyond, he replied, ”Absolutely. India has the technical capability and will soon prove it to send an unmanned scientific spacecraft to the moon.”


”And frankly India has the intrinsic capability to, within quite a few years to be conducting human space flights if they wish to do so,” he added.

India is today a force to reckon with among the comity of space faring nations, with 11 communications satellites in orbit, the largest domestic constellation in all of Asia Pacific and with seven remote sensing satellites in space India today can map at resolution less then a meter. ISRO can now truly dream big.

source:http://www.ndtv.com

Posted in News | Leave a comment

Putting the villages on the map in DR Congo

Posted on April 29, 2008 by Rashid Faridi

Hundreds of villagers are helping to map parts of the Democratic Republic of Congo where thick forest and conflict have prevented effective mapping.

So far about 190 villages have been found in one area of Bandundu province where old maps show only 30, UK-based charity The Rainforest Foundation says.

Most maps are produced from satellite images taken from above, but this project is using handheld GPS units. The map is intended to aid post-war planning and timber permit allocations.

A five-year conflict in DR Congo ended in 2003.

Resource-rich
“In one of the sectors of the territory that the groups are mapping at the moment, there are something like 190 villages, but on the official map there are about 30,” Cath Long of the Rainforest Foundation which is organising the project told the BBC’s Network Africa.

She said millions of Congolese depend on the forest for their existence.

“The real worry is that permits to cut timber, permits to extract resources will be given to external companies without recognising the fact that people are already there and already using the forest,” she said.

The charity hopes the map will be ready for a government meeting in May on forest and land.

The government has already allocated parts of the territory to 11 logging concessions, it says.

DR Congo is home to one of the word’s largest rainforests and has huge reserves of gold, diamonds, copper and coltan, used to make mobile phones.

Correspondents say these riches have been a key factor in the civil wars, instability and bad government the country has known since independence.

Source : http://news.bbc.co.uk/

Posted in News, Remote Sensing 101 | Leave a comment

RADAR AND MICROWAVE REMOTE SENSING

Posted on April 29, 2008 by Rashid Faridi

Electromagnetic radiation at long wavelengths (0.1 to 30 centimeters) falls into a segment of the spectrum commonly called the microwave region. At still longer wavelengths (centimeters to meters) the radiation is known as radio waves (these can be generated by manmade transmitters or occur naturally [e.g., beamed from energetic stars]). Remote sensing has utilized passive microwaves, emanating from thermally activated bodies. But, in much more common use (since World War II) is another manmade device, radar, an active (transmitter-produced) microwave system that sends out radiation, some of which is reflected back to a receiver. The varying signal, which changes with the positions and shapes of target bodies, and is influenced by their properties, can be used to form kinds of images that superficially resemble those recorded by Landsat-like sensors. This first page introduces certain basic principles, describes the common radar bands in use, and shows a typical radar image.

Radar Defined

Radar is an acronym for Radio Detection and Ranging. Radar is an active sensor systems. It generates its own illumination as an outgoing signal that interacts with the target such that some of the signal is returned as backscatter that is picked up by the same antenna that emitted the radar beam. Radar operates in part of the microwave region of the electromagnetic spectrum, specifically in the frequency interval from 40,000 to 300 megahertz (MHz). The latter frequency extends into the higher frequencies of the broadcast-radio region. Commonly used frequencies and their corresponding wavelengths are specified by a band nomenclature, as follows:

  • Ka Band: Frequncy 40,000-26,000 MHz; Wavelength (0.8-1.1 cm)
  • K Band: 26,500-18,500 MHz; (1.1-1.7 cm)
  • X Band: 12,500-8,000 MHz; (2.4-3.8 cm)
  • C Band: 8,000-4,000 MHz; (3.8-7.5 cm)
  • L Band: 2,000-1,000 MHz; (15.0-30.0 cm)
  • P Band: 1,000- 300 MHz; (30.0-100.0 cm)

This chart summarizes the above information on Bands in the Microwave segment of the EM Spectrum:

The Microwave Band assignments

Unlike other sensors that passively sense radiation from targets illuminated by the Sun or thermal sources, radar generates its own illumination (hence, it is active; another example is the flash camera) by sending bursts or pulses of EM energy that reflect off of a target. A fraction of the reflected energy then returns to the radar’s receiving antenna, which collects it and passes it to an electronic processing system. A radar system is a ranging device that measures distances as a function of round trip travel times (at light speed) of a directed beam of pulses (the signal, whose strength is measured in decibels, dB) spread out over specific distances. In this way radar determines the direction and distance from the instrument (fixed or moving) to an energy-scattering object. We can also derive information about target shapes and certain diagnostic physical properties of materials at and just below the surface, or from within the atmosphere, by analyzing signal modifications.

By supplying its own illumination, radar can function day and night and, for some wavelengths, without significant interference from blocking atmospheric conditions (e.g., clouds). These characteristics prompted radar development in World War II for tracking (attacking) aircraft and ships. Ground (fixed) and airborne (mobile) radar systems are used extensively today for marine navigation and air traffic control. Imaging radar, mounted on air or space platforms, has proven especially useful in mapping cloud-shrouded land surfaces (a landforms map of Panama used this approach). This use also permits expressing surface shapes in regions heavily covered by vegetation (penetrated by some bands).

 Radar has become increasingly important in various applications of remote sensing. The military continues to be a prime user. Several satellites operating now have radar has their principal sensor. Most of us are most familiar with radar’s use in Meteorology, mainly as a tracker of storms, rainfall, and advancing fronts. We will skip further reference to this last use in this Section; it is defered until Section 14 that deals with Meteorological Remote Sensing.

This ability to mirror ground surfaces for displaying topography is a prime use of radar for a variety of applications. Some radars operate on moving platforms; others are fixed on the ground. The usefulness in determining land surface configurations is strikingly confirmed in the radar image strip (SIR-A system on the Shuttle) shown here, extending 300 km (200 mi) to the northeast (right side) across the folded and dissected South American Andes in Bolivia. The image covers from the high plains (Altiplano) on the west to the lowlands (Amazon Basin) on the east. (Scroll to see this right end.)

B/W SIR-A radar image of the South American Andes, Bolivia.

 

Radar systems, as well as passive sensors operating at microwave wavelengths (slightly shorter than radar), are also effective in detecting soil moisture, storms-clouds-rain, and sea states.

source:http://rst.gsfc.nasa.gov

Related articles
Posted in Remote Sensing 101 | 1 Comment

Imagery for Everyone

Posted on April 28, 2008 by Rashid Faridi

RESTON, VA – The USGS Landsat archive is an unequalled 35-year record of the Earth’s surface that is valuable for a broad range of uses, ranging from climate change science to forest management to emergency response, plus countless other user applications. Under a transition toward a National Land Imaging Program sponsored by the Secretary of the Interior, the USGS is pursuing an aggressive schedule to provide users with electronic access to any Landsat scene held in the USGS-managed national archive of global scenes dating back to Landsat 1, launched in 1972. By February 2009, any archive scene selected by a user – with no restriction on cloud cover – will be processed automatically to a standard product recipe, using such parameters as the Universe Transverse Mercator projection, and staged for electronic retrieval.

In addition, newly acquired scenes meeting a cloud cover threshold of 20% or below will be processed to the standard recipe and placed on line for at least three months, after which they will remain available for selection from the archive.

Newly acquired, minimally cloudy Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data covering North America and Africa are already being distributed by the USGS over the Internet at no charge, with expansion to full global coverage of incoming Landsat 7 data to be completed by July 2008 (see timeline below). The full archive of historical Landsat 7 ETM+ data acquired by the USGS since launch in 1999 will become available for selection and downloading by the end of September 2008. At that time, all Landsat 7 data purchasing options from the USGS, wherein users pay for on-demand processing to various parameters will be discontinued.

By the end of December of 2008, both incoming Landsat 5 Thematic Mapper (TM) data and all Landsat 5 TM data acquired by the USGS since launch (1984) will become available, with all Landsat 4 TM (1982-1985) and Landsat 1-5 Multi-Spectral Scanner (MSS) (1972-1994) data becoming available by the end of January 2009. All Landsat data purchasing options from the USGS will be discontinued by February 2009, once the entire Landsat archive can be accessed at no charge.

Landsat scenes can be previewed and downloaded using the USGS Global Visualization Viewer at http://glovis.usgs.gov [under “Select Collection” choose Landsat archive: L7 SLC-off (2003-present)]. Scenes can also be selected using the USGS Earth Explorer tool at http://earthexplorer.usgs.gov [under “Select Your Dataset” choose Landsat Archive: L7 SLC-off (2003-present)]. For further information on Landsat satellites and products, see http://landsat.usgs.gov

Source : http://landsat.usgs.gov/

Posted in News, Remote Sensing 101 | Leave a comment