ENHANCEMENT OF SHIPBOARD ADCP DATA WITH DGPS POSITION AND GPS HEADINGMEASUREMENTS

Navigation errors contribute substantially to errors in shipboard ADCP data. Position measurement errors require long averaging intervals to reduce their effect, and heading errors produce systematic bias in un derway data. With Differential GPS (DGPS) position fixing and GPS atti tude measurement, each of these errors can be reduced to 1 cm/s for 10 -min ADCP data. DGPS pseudorange corrections produced almost continuou s coverage with 4-m rms errors at a range of 2000 km from a reference station; even at 4500 km from a reference station the data were worthw hile. GPS heading measurements were used to reveal the deficiencies in a gyrocompass over a 24-h period. Although coverage was not quite con tinuous, linear interpolation of gyrocompass error was sufficient to f ill the gaps. Copyright (C) 1996 Elsevier Science Ltd.