| 摘要 |
PURPOSE:To approximate the variance of position measurement due to the variance of measured values to that due to the variance on a base line independently of the magnitude of the divergence of lines of positions in the position measurement system having a filter for position measurement which performs the averaging processing of the output of a radio navigator. CONSTITUTION:An index smoothing filter 2 for position measurement consists of a multiplying circuit 20 which multiplies measured data from a loran 1 by a coefficient 1-alpha, an adding circuit 21, a delay circuit 22 which delays the output of the adding circuit 21 till the next data acquisition, and a multiplying circuit 23 which multiplies the output of the delay circuit 22 by a coefficient alpha and feeds back the result to said adding circuit 21, and the output of the adding circuit 21 is the filter output. A degree (h) of divergence of lines of positions is obtained in an (h) calculating circuit 6 on a basis of the position measurement result obtained in a position measuring circuit 3 and station positions stored preliminarily in a memory 5. The coefficient alpha of the filter 2 is obtained in an alpha calculating circuit 7 on a basis of this degree (h) of divergence. The coefficient of the filter for position measurement is increased for a high degree of divergence of lines of positions and is reduced for a low degree of divergence of them, and thus, the averaging processing is performed. |
