caps2004183

Description of the Cassini CAPS IMS time-of-flight (TOF) raw data files:

In this directory we have the raw data binary files with name /TOF_200418300_U2.DAT, which covers 6 hours of data from 0 to 6 hours, which includes the time when Cassini was between the F and G rings, respectively. The useful data was from 2004-183T04:19:23 to 2004-183T04:44:27. The other data sets are for the rest of day 183 or July 1, 2004, SCET. The program tof_read.f90 reads these binary files and produces the text file tof-183.dat file which can be viewed using the standard text editor. A description of the TOF files is given in  /TOF_200418300_U1.LBL In that file it refers to the other file TOF_U2.FMT; this file gives a description of the headers in tof-183.dat. Opening the file tof-183.dat, the header from left to right is bcycle # = 1; the decimal time ET = 141912106.091; the time that was converted by the Spice Kernal routine TIMOUT from ET decimal time to UTC_STR = 2004-07-01T00:00:41;  next is the telemetry rate = 8000; collapse flag = 1 or sum nearby energy channels,; ST_START Channel = 0; ST_INTERVAL =  4 (every 4th word is taken starting at ST_START_CHANNEL); ST_ENERGY_COLLAPSE = 0 (sum adjacent energies); LEF_START Channel = 0; LEF_INTERVAL =  4 (every 4th word is taken starting at LEF_START_CHANNEL); LEF_ENERGY_COLLAPSE = 0 (sum adjacent energies); and ENERGY_STEP = 5 (There are 64 energy steps for the singles data (some not used, see ref in paper by Smith et al. (2017)), while 32 energy steps for the TOF Bcycle data (i.e., 64 collapsed to 32). You will then see the words ST_DATA: followed by 16 columns x 32 rows or 512 words of ST TOF data; this is the followed by LEF_DATA: followed by 16 columns X 32 rows or 512 words of LEF TOF data. You will then see the next energy step = 6 now but the same Bcycle = 1. Once you advance to the lower energy or highest energy step # = 32 after which Bcycle = 2 starts with energy step = 5; evidently 1-4 not being used. During this period there was noise in the telemetry so some of the data is missing.