The “program.txt� file is a plain text file containing a three or four column table. Empty lines are ignored, comments starting with a ‘#’ as well. The numbers in the table are parsed as floating point numbers which only may consist of decimal digits, one decimal point ans an optional leading ‘-’ if negative. The columns must be separated by an arbitrary number of space or tabulator characters. They have the following meanings:

1. time stamp — The time stamp must be a Julian date with the time of day coded as a fraction of a day. Example: The Julian date for the common base of most computer clocks (1970-01-01 00:00:00) is 2440587.5
2. azimuth angle — The azimuth angle in degrees
3. elevation angle — The elevation angle in degrees
4. polarization angle — The polarization angle in degrees. This column is optional, no polarization pointing is commanded if this column is missing.

The example below shows an excerpts of a program tracking file containing azimuth and elevation angles

2459145.02083333           159.5000              32.2000
2459145.02222222           159.6000              32.2150
2459145.02361111           159.7000              32.2300
2459145.02500000           159.8000              32.2450
.
.
.
.
2459145.48194444           192.7000              37.1800
2459145.48333333           192.8000              37.1950
2459145.48472222           192.9000              37.2100
2459145.48611111           193.0000              37.2250

Memory space is very limited in the ACU-ODM. The file size is limited to 64 Kbytes, being equivalent to about 12 days of AZ/EL data in 10 minutes intervals.