What direction is the heading on my LD900?

The LD900 GNSS heading direction is computed from GNSS 1 to GNSS 2, with the accuracy of the solution largely determined by the distance (or baseline) between both antennas. The larger the baseline, the better the heading precision will be. Veripos recommend a minimum baseline of two metres:

If the GNSS antennas are mounted along the vessel centreline, with GNSS 2 being the furthest forward antenna, the GNSS heading would closely reflect the vessel’s heading. In the below example, a small heading alignment correction (C-O) may be required after calibration:

If GNSS 1 and GNSS 2 are installed perpendicular to vessel centreline with the GNSS 1 on the port side and GNSS 2 on the starboard side, a larger correction offset (C-O) is required in the navigation software to align the GNSS heading to Vessel heading, as the GNSS heading is approximately +90 degrees greater than the vessel heading. The C-O offset can be entered in the navigation software or the LD900, however, care should be taken not to enter this offset in both systems.