To generate a spectrogram, click on the CONTINUE button below. You will be presented with the Spectrogram Date Selection form for entering the date of interest. Clicking on the Continue button on this form will take you to the Spectrogram Viewer. There, you will be able to specify the satellite, start time, and duration for the spectrogram. You can also choose whether or not to annotate the spectrograms with dayside regions and nightside crossings and to produce the image with either black or white background.

It may takes about one to two minutes to receive your spectrogram. The image will be displayed in PNG (Portable Network Graphics) format with the size you specified. A larger image may take longer to transmit than a smaller one.

Note:
The glat and glon displayed on the spectrogram were determined using the NORAD routines for the satellite number contained within the data file.

Caution:
The low-energy ion heads on F13 and F15 did not work as well as expected, and the counting statistics are not as good as most other DMSP satellites. Nonetheless, evidence indicates that the particle data from these satellites is generally reliable.