TerraSAR-X active radar ground calibrator system

In April 2006, the TerraSAR-X satellite was launched. This paper describes the development of a novel and highly integrated, digitally-controlled active SAR system calibrator (DARC). It consists of both an active transponder path for absolute radiometric calibration and a calibrated receiver chain for antenna pattern evaluation of the satellite antenna. A total of 16 active transponder and receiver systems and 17 receiver-only systems will be fabricated for a calibration campaign in 2006.     

Measuring Rotational Motion with Linear Accelerometers

Inertial navigation systems usually use gyroscopes to sense angular motion and use accelerometers to sense linear acceleration. It is feasible, however, using only linear accelerometers as sensors, to determine both the angular velocity and the linear acceleration of a vehicle. This paper presents and compares five configurations of linear accelerometers which may be used to determine both the angular motion and the linear motion of a vehicle.