The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Passive SAR data have been registered using the airborne low frequency SAR system LORA. For this purpose, the radar sensor was reconfigured to not transmit any signals but only gather data along the pre-defined synthetic aperture. The receiver unit was tuned to fully accommodate the DVB-T signal centred at 634 MHz (channel #41), acting as the illuminator of opportunity within the ground scene mapped...
In this paper, the potential of mono- and bistatic HH-polarized UHF-band SAR imagery for mapping of a hemi-boreal forest is studied. SAR data have been acquired with the two airborne SAR sensors LORA and SETHI during a joint FOI-ONERA campaign conducted in 2010. Three acquisition modes are compared: monostatic, quasi-monostatic (difference in elevation angle around 0°) and bistatic (difference in...
Bistatic and passive radar are emerging technologies for covert ground surveillance based on cooperative or non-cooperative transmitters, respectively. The latter uses transmitters of opportunity, e.g. terrestrial digital video broadcasting (DVB-T). In the paper, we show results from two unique experiments conducted using airborne systems operating in the VHF and UHF bands. The first experiment investigates...
The paper presents results from developing and testing a bistatic SAR system for ground surveillance in the VHF band (25–83 MHz). It is based on two radars developed by FOI: The monostatic LORA system installed in an aircraft and the bistatic and passive CARINA system installed on a helicopter. CARINA is based on direct RF sampling of two receiver channels (2 × 14 bits @ 250 MSPS) together with continuous...
Synthetic Aperture Radar (SAR) backscatter data from the Swedish airborne CARABAS-II and LORA systems were used to estimate stem volume at stand level. The study was performed in hemi-boreal forests at the Remningstorp test site, located in southern Sweden. In total, ten 80 m × 80 m stands, where all trees were measured in situ, with stem volumes in the range of 70–530 m3 ha−1 (on average 347 m3 ha...
Low frequency synthetic-aperture radar (SAR) in combination with change detection techniques can be used to search for stationary ground targets. In particular, the method has shown a great potential when vehicle-size objects are obscured by foliage. However. one possibility is to improve the detection capabilities to increase the aperture angle of the radar data acquisition to make sure that the...
We present results from the LORAMbis bistatic VHF/UHF-band SAR experiment conducted in September 2010. The SAR flights were performed with the French SETHI system and the Swedish LORA system installed in two aircraft. Frequency band was 222–460 MHz and polarization was HH. Results from two tests sites (Kvarn and Remningstorp, both in southern Sweden) show that forest clutter generally decreases for...
The ESA funded campaign BioSAR 2010 was carried out at the forestry test site Remningstorp in southern Sweden, in support to the BIOMASS satellite mission under study. Fully polarimetric SAR data were successfully acquired at L- and P-band using ONERA's multi-frequency system SETHI. In addition with other data types gathered, e.g. LiDAR and in-situ measurements, the compiled data set will be used...
Radar imaging of tropical vegetation at VHF- and UHF-band has been performed using the airborne SAR sensors CARABAS-II and LORA, respectively. The acquired data set is limited to HH-polarized registrations only. The area mapped exhibits a rough terrain with dramatic topographic variations, mostly covered by dense tropical rain forests. Multiple illumination directions spanning 360° were adopted in...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.