遥感卫星技术发展趋势

Earth Observation Satellite Technology Trends: An eye in the sky

Publish Date: 22 February 2012

Prof. Arup Dasgupta

Managing Editor

Geospatial World

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<< Satellite industry is witnessing changes like never before. The advancement in technology is creating ample opportunities for this industry, and in the process, setting new trends... >>

The technology of earth observation has seen many changes over the past few years with four major trends emerging. The first is the government-funded missions for earth observation, using a variety of sensors on large satellites which address mapping as well as scientific studies. The news, however, is

dominated by the second trend consisting of commercial imaging satellites with sub-metre spatial resolution for land applications. The third is a shift away from big multi-sensor satellites towards small singlefunction satellites. The fourth trend is to use small satellites in constellations and swarms. Furthermore, these trends tend to overlap with each other. RapidEye is a commercial constellation of small satellites while Disaster Monitoring Constellation (DMC) is government owned but operated by DMCii.

Satellite trends

Large earth observation satellites are being supported by government agencies. India has its IRS series and is perhaps the only country to have such a large commitment to continuing government-funded earth observation satellites and application programmes. Apart from its workhorses, INSAT, RESOURCESAT and CARTOSAT, the Indian programme also involves the piggyback launching of small satellites from different countries and more recently nanosatellites like SRMSat and Jugnu from educational institutions. Joint programmes include Megha- Tropiques and SARAL, in collaboration with CNES, France.

The recently launched Pleiades 1A is the first of a new generation satellites operated by Astrium Services. Pleiades 1A will be followed between 2012 and 2014 by SPOT 6, its twin Pleiades 1B and finally SPOT 7. Built around similar architecture and phased in the same orbit, the constellation of four satellites will ensure better responsiveness and availability of 50 cm to 2 m products through to 2023. Pleiades is a component of the ORFEO programme in which Italy is a partner with its COSMO-Skymed series of satellites.

The US Landsat programme has ended with Landsat 7. NASA has launched the new millennium programme (NMP) for next generation spacecraft. The first was EO-1, which, among other mission goals, was flown in constellation mode with Landsat 7. EO-1 mission has ended and the NMP has no other satellites planned. The Landsat Data Continuity Mission (LDCM) is expected to be launched in late 2012 and will carry two sensors, the operational land imager, OLI and the thermal infrared sensor, TIRS. NASA is also concentrating on their follow-on to the EOS missions, the earth systematic missions (ESM) programme which will continue to advance understanding of the climate system and climate change. The ESM is a three-tiered programme. Apart from this, there are joint missions with NOAA for weather and climate studies.