In contrast to passive remote sensing technologies such as optical satellite imagery, the use of active remote sensing technologies such as RADAR means that data can be collected under any weather conditions, in any part of the world. Imagery data in areas frequented by clouds and rain, like the tropics, can now be obtained easily and cost effectively with the following sensors:
JERS-1
Developed by the National Space Development Agency of Japan (NASDA), the JERS-1 satellite was launched in February 1992. Data collected by JERS-1 has a spatial resolution of 18m and maintains a wavelength of 23.5cm giving it an L-Band central frequency. The JERS-1 archive has a global revisit of 44 days and imagery was collected until late 1998.
RADARSAT 1 and 2
Developed by the Canadian Space Agency (CSA), RADARSAT 1 was launched in 1995 providing RADAR imagery down to a resolution of 10m, whilst maintaining a wavelength of 5.6cm (C-Band). RADARSAT 2 was launched in December 2007 as a part of the continued success of its predecessor providing RADAR imagery down to 3m. Both satellites are currently collecting imagery globally, steadily building an excellent archive with added continuity.
PALSAR
The PALSAR sensor lies on-board the ALOS sensor developed and launched by NASDA in January 2006. The PALSAR sensor collects imagery down to 10m in fine acquisition mode and maintains an L-Band frequency. The ability in being able to simultaneously combine PALSAR data with the optical ALOS and PRISM sensors on-board the same satellite gives it a particular edge over its competitors.
For more information on any of the above RADAR sensors please email remote.sensing@ngis.com.au