The French quadristatic incoherent scatter facility

摘要: The original Nancay-St. Santin incoherent scatter facility based on the radio astronomy antenna at Nancay and a CW transmitter located St. (300 km south) was improved in many ways between 1965 1970: doubling of transmitted power to 140 kw, lowering receiver noise level down 100 K, monitoring data acquisition through use computer, rejection parasitic tropospheric echoes. However, most important improvement brought system is addition two new receiving stations east west transmitter. Each equipped with three-beam Cassegrain (25-m parabola) aimed simultaneously intersect vertical beam three different heights. Both receivers have wide band (38 MHz 3 db) gaseous helium cooled parametric amplifiers on-line computers. While one filter banks for purpose spectral analysis, choice has been made other station. For latter will imply multibit correlators, both ionic spectrum plasma line measurements. Most electronic equipment designed also implemented receiver. frequency time synchronization four sites now accomplished by employing single 5-MHz standard each station monitored signals from MSF and/or HBG stations. The observation procedure consists tilting antennas so as gather signal scattered ionospheric column illuminated calibration purposes ionosonde operating Santin. The main objective quadristatic determine completely ion drift vector order study electric fields neutral tidal winds. Other capabilities offered are determination higher rate. The first observations were performed December 1972.