Abstract
Sources of errors in laser Doppler velocimeter are studied by calculating interference image produced by diffraction images of two beams come out at their convergence region. About 4% error is caused by an omission of fringe at the summit of each beam in the both 1/4 ends of the measuring region. The other about 6% error is caused by interference fringes generate on two beams outsides of the measuring region. These errors may be incompletely removed by hi-pass filtering of the measured signal. The more complete countermeasure than the former is to raise the threshold of effective fringes
