Satellites and current measurement: Caveat emptor

This paper briefly describes the major sources of errors and pitfalls to be encountered in using satellite techniques to measure ocean currents. Although several developing techniques are mentioned, the paper concentrates on radiometric and altimetric satellite remote sensing measurements and the use of spaceborne data collection and location systems to track quasi-Lagrangian drifters. While the total errors attributable to these techniques are found not excessively large (order centimeters per second), it is concluded that spacecraft measurements are most appropriate for sampling large-scale, low-frequency phenomena.