HF scatter from artificial irregularities above Tromso

The paper summarises some observations of backscatter from artificial irregularities produced by the Tromso heater. The observations were carried out with the newly constructed CUTLASS radar which is located in Finland. A second stage of the CUTLASS system is under construction in Iceland. CUTLASS is an HF phased array radar operating at frequencies between 8 and 20 MHz and is capable of electronic beam scanning. As a result, it has been possible for the first time to study of the extent of the heated region in a plane perpendicular to the geomagnetic field.