|
|
Experimental radar provides 3-D forest view   A variety of different tropical forest types in Kalimantan, Indonesia was the subject of the INDREX-II airborne radar campaign in November 2004. The aim was to gather a database for the investigation and validation of bio/geophysical parameters obtained from L- and P- band polarimetric interferometry (Pol-InSAR).  The Second Indonesian Airborne Radar Experiment (INDREX-II), involved flying DLR's Experimental Synthetic Aperture Radar (E-SAR) in the Agency's Dornier-228 aircraft over eight test sites around Kalimantan on the island of Borneo.  Here is shown a single-baseline Pol-InSAR forest height inversion from INDREX-II data. The left image is forest imaged in L-band HH. From this through processing is obtained a forest height map with maximum height at around 58 metres and mean height between 25 and 30 metres.  Validation of the Mawas INDREX-II test site in Kalimantan was carried out based on eight transects along the 23-kilometre walking bridge. Within the transect each tree is observed. Observables included species, location, total tree height, height to first branch, and terrain height, estimated biomass, meteorological data - rainfall, temperature; 3 gauges - and hydrological data - water levels; 15 gauges. What is Pol-InSAR?  Radar interferometry to produce Digital Elevation Models - this one showing how a pair of images from twin ERS satellites were used to create one of the Etna volcano in Sicily, Italy. Pairs of images acquired from the same spacecraft during different orbits can also be used.  Interferogram of Mount Etna derived from ERS-1 and ERS-2 Synthetic Aperture Radar data 1-2 August 1995  Colour composite of airborne radar images acquired at three different frequencies (L-, C- and X-band) by the DLR E-SAR system during the ESA TerraSARSIM campaign in Barrax, Spain, in April 2003. The aim of the campaign was to investigate the effect of different acquisition times for each frequency on the combined information content of the three frequencies in support of the ESA TerraSAR L project.
The circular fields in the image are typical of pivot irrigation systems installed in the area. The light green slice in the circular field located in the upper right of the image illustrates the enhanced radar return due to the wet soil conditions after the pivot boom had passed over the area.  SAR Polarimetry data: L-band RGB from DLR's E-SAR sensor over the Sungai Wain South test site, Indonesia. The data was acquired during the INDREX-II campaign.  The INDREX-II campaign involved transporting tonnes of specialised equipment from Germany to Indonesia via India. This included the E-SAR instrument itself. Putting Pol-InSAR into space?  INDREX-II Release date: 1 February 2005 |