Riometer Data Format

IPS holds Riometer data come from four stations. they are Casey, Davis, Mawson and Macquarie Islands. Originally, Riometer data are binary daily file. Available Riometer data file on IPS webaite and FTP server are converted text files. Each text riometer file name starts with "ri" followed by year, month and day, and extension is three letter station name abbreviation and '.gz".

e.g. ri080301.cas.gz is a text Riometer data file for 1st of march 2008, Casey station.
First line of each file is a short description of the file, Followed by data record lines, each line has six fields, they are hour, munute, second, Raw(DU), QDC(DU) and Absorption(dB) with one record every 10 seconds.

In these riometer data sets, DU stands for "digital units". The analog riometer output is converted to digital data at the point of data collection (i.e. at the Antarctic bases), so we never see the original analog values here. The conversion process involves adding an analog offset (-5V) to put the riometer signal near the middle of the A to D dynamic range (+/-5v), applying a gain of x2, then converting to a signed 12-bit digital value. The possible range of digital values is then ± 2048 bits, or DU.

Following is a part of the text riometer file ri080301.cas.gz.