EISCAT radar operations are divided equally between Common Programmes (CP) and Special Programmes (SP). They include detailed observations over a wide range of altitudes and over a large geographic area.
The scientists of the EISCAT Associates (the Federal Republic of Germany, Finland, France, Japan, Norway, Sweden and the United Kingdom) have developed many specialized programmes for these purposes.
Three UHF Common Programmes and three VHF Common Programmes are run about thirty times each year, for at least twenty-four hours, to provide a data base for long term synoptic studies. In addition, three Unusual Programmes (UP) can be started at short notice during particular, less predictable geophysical conditions and EISCAT is a member of a world-wide network which co-ordinates the activities of Incoherent Scatter radar facilities to cover such events.
Common Programme One (UHF) uses a fixed transmitting direction along the local magnetic field to measure electron density, electron and ion temperatures and velocity along the radar beam as functions of altitude. The full, three-dimensional plasma velocity vector and anisotropies in temperature are measured using all three EISCAT sites including the receiving stations at Kiruna and Sodankylä. Common Programme One is capable of providing results with very good time resolution and is suitable for the study of rapid changes in auroral phenomena. On longer time scales, Common Programme One measurements are also used in studies of diurnal, seasonal and solar cycle variations.
Common Programme Two (UHF) is designed to obtain measurements using a rapid (less than ten minutes) transmitter antenna scan and is particularly intended for the study of travelling disturbances which perturb the ionosphere upper atmosphere.
Common Programme Three (UHF) covers a wide band of latitudes measuring at seventeen individual points during a thirty minute scan. The measurements are made in a north-south plane through Tromsø and Kiruna with the antenna beams of the receiver sites tracking the transmitter beam in the F-region between 64 N and 74 N.
Common Programme Four (VHF) reaches yet higher latitudes, approaching 80 N under favourable conditions. It is well suited to studies of ionospheric flows to the north of the auroral zone, where the effect of the solar wind causes the plasma to stream over the pole away from the sun-ward side of the Earth. It uses the VHF radar in split-beam mode to measure both towards the geographic North North and somewhat to the West simultaneously.
The two remaining VHF Common Programmes are optimised for D-region/mesosphere and very high altitude studies (above 1000 km). The low altitude program, Common Programme Six, covers a restricted altitude range at high resolution and accurately determines the spectrum of the scattered signal to allow detailed studies of this important region. In contrast, Common Programme Seven uses long pulses to make observations at the highest altitudes accessible to the radar in order to study the flow of plasma between the ionosphere and the magnetosphere.
Unusual Programmes are available for times when large numbers of energetic particles reach the lower ionosphere, for Sporadic-E layers and for auroral arc studies.
The development of the Common Programmes is the result of close co-operation between scientists at EISCAT, in the Associate countries and on the Scientific Advisory Committee.
New Common Programmes are being developed for use with the EISCAT Svalbard Radar.
Updated by Tony, Thursday, 16-Jan-97 11:31:22 MET