Images of fields data acquired by the FAST spacecraft
launched Aug 21st 1996

FAST Principal Investigator
Charles W. Carlson, Space Sciences Laboratory, U.C. Berkeley

FAST Fields Instrument Team
Robert E. Ergun, Space Sciences Laboratory, U.C. Berkeley
Cynthia A. Cattell, University of Minnesota
Richard C. Elphic, Los Alamos National Laboratory
Forrest Mozer, Space Sciences Laboratory, U.C. Berkeley
Robert J. Strangeway, IGPP, UCLA
Michael Temerin, Space Sciences Laboratory, U.C. Berkeley
Below is a plot of a ~7 minute stretch of the 21" search coil spectra taken over the polar cap. Whistler wave emissions can be seen from ~10:28 UT to ~10:31 UT in the ~2 kHz to >16 kHz frequency band. A strong burst is seen at ~10:30. The SFA (swept frequency analyzer) shows the VLF emissions as high as ~200 kHz at ~10:30 UT. The 9 kHz and 14 kHz lines (18 kHz folded about 16 kHz) are the fluxgate drivers that are seen because the magnetometer booms are still stowed.

The magnetometer booms were deployed on orbit 25 ~19:00 UT. Below is a plot of the fluxgate and search coil survey raw data. Fluxgate is ~2 nT per bit.

Below is an auroral crossing made by the FAST satellite after the magnetometer boom deployment. The top plot is a spectrogram of the 21" search coil signal in the 0 to ~16 kHz frequency range computed on-board. The bottom plot is the 0 - 2 MHz spectra. We interpret the emissions as near-lower hybrid frequency whistler waves in the auroral zone. The space craft position was ~70 deg N Lat., ~100 deg. W Long., and ~1700 km altitude.

We have also converted the on-board Fast Fourier Transform data from the 21" search coil (top plot) to audio. The frequency has been compressed by a factor of 8 while the time has been compressed by a factor of 4 in the audio file. Because of the noisy nature of the audio, we recommend that you decrease the volume when you play this sound file.

Below is a southern crossing made by the FAST satellite after the magnetometer boom deployment. The top plot is a spectrogram of the 21" search coil signal in the 0 to ~ 16 kHz frequency range computed on-board. The bottom plot is the 0 - 2 MHz spectra. We interpret the emissions in the top plot as near-lower hybrid frequency whistler waves in the auroral zone and magnetospheric hiss.

We have also converted the on-board Fast Fourier Transform data from the 21" search coil (top plot) to audio. The frequency has been compressed by a factor of 8 while the time has been compressed by a factor of 16 in the audio file. Because of the noisy nature of the audio, we recommend that you decrease the volume when you play this sound file.

FAST related links

FAST home page at NASA/Goddard Space Flight Center

FAST home page at Space Science Laboratory - U.C. Berkeley

FAST magnetometer home page at UCLA

FAST VLF Survey Plots - Online JPEGs

Robert J. Strangeway
Institute of Geophysics and Planetary Physics / UCLA
Los Angeles, CA 90024-1567
Telephone: (310) 206-6247
FAX: (310) 206-3051
Internet e-mail: strange@igpp.ucla.edu
NSI/DECnet e-mail: FSCARF::STRANGE

IGPP/UCLA Space Physics Center home page     IGPP/UCLA FAST home page     Bob Strangeway's home page

Last modified: September 2nd, 1996.