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Eye on Upcoming SAR sensors


This year is a big year for the launch of new SAR sensors. For those of you interested in utilizing the advantages of SAR data, which include penetration of clouds and collection even at night, here is a roundup of new and upcoming SAR missions:


The European Space Agency's Sentinel-1A satellite successfully launched on 3 April 2014. Sentinel-1A is the first of two Sentinel-1 satellites designed by the ESA. It's payload is a C-band Synthetic Aperture Radar.

Sentinel-1 is designed to ensure SAR data continuity following the retirement of ERS-2 and the end of the Envisat mission. Sentinel-1 will also incorporate important improvements relative to its predecessor missions. Among the most important is the fact that Sentinel-1 will be a continuously operational satellite, which requires improved reliability and provides faster revisit times, geographical coverage and rapid data dissemination. Each of the Sentinel-1 satellites will have a 12-day repeat cycle at the equator, with the pair reaching a 6-day repeat once Sentinel-1b is launched. Over Europe and Canada, the Sentinel-1 pair is expected to provide near-daily coverage, with delivery of radar data within an hour of acquisition.

The Sentinel-1 systems are designed for operational interferometry, meeting requirements for attitude accuracy, attitude, and orbit knowledge, and data-take timing accuracy. Sentinel-1 is designed to address medium-resolution applications with its main mode: a wide swath (250 km) and medium resolution (5 m range x 20m azimuth).

The first radar images from Sentinel-1A were captured April 12. Sentinel-1A is expected to become fully operational around mid July. Sentinel-1b is scheduled to launch in 2015.


The Phased Array typeL-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite-2 (ALOS-2, a.k.a. "DAICHI-2") is a follow-on mission to the radar component of the ALOS, a.k.a. "DAICHI", mission. ALOS-2 is currently scheduled to launch on May 25, 2014.

PALSAR and PALSAR-2 are L-band Synthetic Aperture Radar systems. The enhanced capabilities of PALSAR-2 relative to PALSAR will include higher resolution and expanded observable range of the satellite. ALOS-2 will have a spotlight mode (1 to 3m) and a high resolution mode (3 to 10m). Moreover, ALSO-2 will have a right-and-left looking function, currently not available on ALOS/PALSAR.


The Satélite Argentino de Observación con Microondas (SAOCOM 1A) mission of the the Argentinian National Space Activities Commission (CONAE) will include an L-band fully polarimetric SAR system with resolution ranging from 10 to 100 m. SAOCOM 1A will also carry a thermal infrared sensor.

CONAE's web site still says SEOCOM 1A is being developed to launch in 2013, and some watchers expect that it may not be launched until 2015. But, I'm optimistically putting it on the list for 2014.

Along with X-band COSMO-SkyMed SAR systems from the Italian Space Agency ASI, SAOCOM 1A and its eventual twin SAOCOM 1B will make up the Italian-Argentine System of Satellites for Emergency Management (SIASGE) constellation. According to CONAE:

"The six satellites (SAOCOM and COSMO SkyMed) shall be placed at the same altitude in polar orbits, on different orbital planes, in such a way that the whole set will work as one instrument with a huge vision width on the Earth. This will enable monitoring in almost real time, since the information shall be updated every 12 hours, which is particularly necessary for the monitoring and tracking of disaster evolution."

Data products CONAE expects to distribute based on SAOCOM data include soil moisture maps and interferometric products.


NASA JPL's upcoming Soil Moisture Active Passive (SMAP) mission will carry an L-band SAR system using VV, HH, and HV polarizations (it will not be fully polarimetric). SMAP will collect higher resolution (250 m) data over land, and low-resolution globally. After multilooking and resampling, SMAP data products are expected to have 1 km resolution over land.

SMAP is designed specifically to provide global measurements of soil moisture and freeze/thaw state. In addition to the L-band SAR sensor, SMAP will contain an L-band radiometer, which will allow it to combine the relative strengths of active and passive remote sensing. The combined radar-radiometer-based soil moisture product will be generated at about an intermediate 9-km resolution with three-day global revisit frequency.

JPL expects to launch SMAP this coming November.