Testing of the usability of the C-band Electronic Corner Reflector (ECR-C) in Hungary based on Sentinel-1 SAR data

<p>The key infrastructural elements of the geodetic application of the Interferometric Synthetic Aperture Radar (InSAR) are the integrated benchmarks which are satellite technologies, besides the traditional geodetic technologies, therefore they serve as benchmarks of the Global National Satellite System (GNSS) and InSAR.</p><p>Previously, the Satellite Geodetic Observatory (SGO) has already built a network of the passive corner reflectors (SENGA) near the Hungarian GPS Geokinematic Reference Network. This infrastructure is added by an active corner reflector (called transponder) which is the first device according to our knowledge in Hungary. We have been testing the transponder in recent months. The scope of our work is the detection of the intensity of the emitted radar signal by the Sentinel-1 C-band satellite VV polarisation sensor using GAMMA Remote Sensing Software with 6 day repeat cycle availability of satellite images in ascending and descending passes. Hence, we could monitor and compare of the pixel-intensity (expressed in decibel) before and after the installation. The value of the pixel is increased around 15-20 dB and we had chance to set the Radar Cross Section (RCS=31 dBm2) against the results of existing researches. <span>During the testing period the ECR was placed on the roof</span><span>top of the </span><span>S</span><span>GO, but in </span><span>the short</span><span>-term the design </span><span>of the relocation of the device as InSAR Persistent Scatterer</span> <span>has also been developed</span><span>.</span></p><p>One of the goals of our research is the incorporation of the transponders into the SENGA network which is needed to be expanded, examination and determination of the conditions of this integration.</p><p> </p>

Geodetic survey of northern Canada by shoran trilateration

A geodetic survey by shoran trilateration, to approximately second-order accuracy, of the islands of the Canadian Arctic archipelago was completed in 1957. This was the culmination of a programme started in the south-central section of the country in 1949.Shoran (short-range aid to navigation) was developed during World War II as a navigational aid for precise tactical bombing. It consists of two radar transponders at known points on the ground and another radar unit in an aircraft capable of measuring the time required for radio waves to travel from the aircraft to each ground station and to return. These times are converted to distances by an intricate electro-mechanical system and the distances are shown on counters, reading to 0·001 mile. For the military application the distance between transponders was known and the position of the aircraft could be plotted from the mileage-counter distances; for geodetic application the mileage-counter distances are used to measure the distance between the two transponders.