DEOS: Dynamics of the Equatorial Over SHAR Sounding Rocket Campaign in South India

Christian T. Steigies
NRC at NASA/GSFC

The DEOS campaign was aimed at investigating the equatorial ionosphere under equinox conditions. During this campaign three sounding rockets were launched in 1998 from SHAR (80.2E, 13.7N) in South India in the evening and night hours. The payloads were identically equipped with five scientific instruments to study various plasma parameters. For redundancy and for a critical cross comparison, the basic plasma parameters were measured with several independent instruments. The electron density was measured with a digital impedance probe (IP), a swept voltage Langmuir probe (LP1), and a resonance cone (RC) instrument. A second Langmuir probe (LP2) in electron saturation mode was used to measure electron density fluctuations. The swept voltage Langmuir probe also yields the electron temperature. Magnetic field measurements are performed with a precision magnetometer (PM). The rocket also carried a radio beacon (RABER) instrument. This instrument transmitted two phase coherent HF frequencies which were recorded by four ground stations. From the phase difference of these two signals the total electron content (TEC) can be determined. Ground-based measurements, which were performed before, during, and after the launches, include ionosonde measurements, VHF radar, and magnetograms.

Results from the impedance and Langmuir probes are presented and compared with ionograms recorded in SHAR.