|Authors||Vahid Rezaali , Alireza A. Ardalan, Naser Abdi|
|Journal||Journal of Geospatial Information Technology|
|Paper Type||Full Paper|
|Journal Grade||Scientific - research|
|Journal Country||Iran, Islamic Republic Of|
Highly accurate parameters for velocity and direction of marine current are of utmost importance in marine studies. To achieve this, accurate and calibrated current meters should be used. The direction parameters or “heading” resulted from marine current meter is measured by the aid of a compass mounted on the device. This, as well as the velocity parameter should be properly evaluated and margin of error calculated. In this paper GNSS receivers have been utilized to calibrate the compass on a marine current meter. In this method, two GNSS receivers have been installed on a buoy and then connected to a current meter. The buoy then has been pulled on a lake in a specified direction. In this method two GNSS receivers mounted on buoy using carrier phase observations have been positioned relative to a reference station and by defining a local level coordinate with the reference station as the origin, from rotation the baseline created between the two receivers to this station, heading angle has been calculated. To verify the accuracy of the calculated heading angle, criterion such as satellite geometry, solving phase ambiguity and multipath error in kinematic positioning is evaluated. Heading angles of the buoy was determined with a standard deviation 48.2760" and were compared with the headings of current meter that mean difference between heading from compass current meter and GNSS heading 26'46" is determined and calibration equation is presented for current meter compass.
tags: heading angle, GNSS, relative kinematic, marine current meter, current meter calibration