spase://SMWG/Instrument/CRRES/PWE

This experiment consisted of the Search Coil Magnetometer (AFGL-701-13-2) and Passive Plasma Sounder (PPS, AFGL-701-15) instruments and was designed to measure the plasma wave environment in the radiation belts. Emphasis was on high frequency and time resolution, on low noise levels and high sensitivities, and on broad frequency response in the range of interest in which most magnetospheric emission occurs. Receiver dynamic range was about 100 dB (factor of 1E5 in amplitude). The Search Coil Magnetometer measured the magnetic field component of plasma waves in the frequency range of 5.6 Hz - 10 kHz and contained a high permeability mu-metal core, 0.4 m long, with 10,000 turns of 42-gauge wire wound around it, and a preamplifier. The output was fed to a multichannel spectrum analyzer, with 14 simultaneous channels. The bandwidth of each channel is 0.3 times the center frequency, except at the frequencies of 5.62 kHz and 10.0 kHz at which the bandwidth is 1.5 times the center frequency. Each of the 14 outputs is sampled 8 times per second for telemetering. The PPS measured the electric field components of plasma waves in the frequency range of 100 Hz to 400 kHz. Signals induced in a 100-m-long dipole were channeled to a 4-band sweep-frequency receiver. Band 1 (100 - 810 Hz) was swept through in 32 s; band 2 (810 Hz - 6.4 kHz) in 16 s; band 3 (6.4 - 51.7 kHz) and band 4 (51.7 - 400 kHz) in 8 s. The sweeps were not continuous, but in discrete step frequencies, with 32 frequency channels in each band. The channel bandwidths of the four bands were, respectively, 7 Hz, 56 Hz, 448 Hz, and 3.6 kHz. The dynamic range of each channel was 100 dB. The 100-m electric antenna in the Langmuir Probe Experiment (NSSDC ID 90-065A-20) provided a third sensor input for the sweep frequency receiver and multichannel spectrum analyser in the Plasma Wave Experiment. This experiment was part of the SPACERAD project sponsored by AFGL.