Some analysts use a third party software package to produce their bearing data. Unfortunately, for towed array data the package calculates the absolute bearing using the current platform heading, not the heading for the platform was following when it was at the current array centre.

But, since the packagea already outputs a data-file containing the relative bearing we're able to do our own calculation of absolute bearing, using a better value for ownship heading.

The data is in two columns, elapsed seconds since the epoch, and the relative bearing in Degreees, like this:

            1263297600.000000, 69.00
            1263297840.000000, 67.85
            1263298080.000000, 65.63
            1263298320.000000, 63.33