New techniques for auroral irregularity studies with COSCAT

• Main Authors: Eglitis, P., Mccrea, I. W., Robinson, T. R., Nygrén, T., Schlegel, K., Turunen, T., Jones, T. B.
• Other Authors: Department of Physics and Astronomy Leicester, University of Leicester, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Physics Department, Max-Planck-Institut für Aeronomie (MPI Aeronomie), Max-Planck-Gesellschaft, Sodankylä Geophysical Observatory, University of Oulu
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1998
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; EISCAT
• Online Access: https://hal.science/hal-00316450; https://hal.science/hal-00316450/document; https://hal.science/hal-00316450/file/angeo-16-1241-1998.pdf

International audience The COSCAT system enables the detection of E-region auroral backscatter with the EISCAT remote receivers at magnetic aspect angles close to 90 ° . This is achieved by utilising a low-power transmitter stationed in Oulu, Finland. Many important observations of E-region irregularities have been achieved with this simple experiment. Recent studies have attempted to push the COSCAT system to its experimental limits. Firstly, the CW signal has been phase-modulated with 13-bit Barker codes with baud lengths of 40, 70 and 100 µs. Interpretation of the received power allows the spatial distribution of the auroral scatterers to be determined. The second advance is in the use of a sophisticated correlator program which allows data to be buffered within the correlator at very high time resolution. This enables the coherent backscatter power to be sampled every 12.5 ms and the full auto-correlation function to be measured every 100 ms. These measurements allow the COSCAT system to be employed for the first time in an investigation of the growth and decay of the auroral irregularities.