HGPS

measured with Simrad ES60 and Olex HGPS to the right.
HGPS also eliminates the effect from tide, seawaves and vessel depth in water. This combination makes the user able to perform exact and repeatable sea floor survey, and acheive a high resolution sea floor map using a single beam echosonder.
For best possible result, roll/pitch sensor and an echosounder with high ping rate is recommended.