This is the gateway to our collection of Freja F2 FFT Plots. Enter either the desired Freja Orbit Number OR the date of interest. If an Orbit Number is entered, the date will be ignored. A list of all available plots will be generated, with the naming convention:

YY-MM-DD_HH_MM_NNNNNSS#.gif

!! There may be a slight delay (~10 seconds) while our server searches for your files.

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Note: Hit "Reset Entries" before entering subsequent dates to avoid unwanted snags.

Enter the Orbit Number :

OR:

Select a Year: 1992 1993 1994 1995 Month: January February March April May June July August September October November December and Day: 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

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Example: 95-01-01-02-20_10800pn1.gif-> is the F2 FFT Plot for 1 January, 1995, Freja orbit number 10800, as recoreded at the Prince Albert ground station (pn=Prince Albert, en=Esrange).

Plot Description

The top panel contains a 0-256 Hz frequency-time spectrogram made up of individual 512 point FFTs of spin-axis (z-axis) high-pass filtered (ac) magnetic field data. The high-pass filter has a 3 dB point at 1.5 Hz and an anti-alias filter at 256 Hz. The spectral power has been corrected for the high-pass filter attenuation at low frequencies (plots with FC=1 label under color bar). The spectrogram is color coded in units of log spectral density (nT2/Hz). The bottom panel contains the average spectral density in the frequency range from 5-30 Hz (green) and 30-255 Hz (red).