| 摘要 |
PCT No. PCT/EP92/00848 Sec. 371 Date Dec. 11, 1992 Sec. 102(e) Date Dec. 11, 1992 PCT Filed Apr. 15, 1992 PCT Pub. No. WO92/18876 PCT Pub. Date Oct. 29, 1992.For distance measurement using the reflected beam principle a transmission wave is transmitted with a periodically frequency modulated transmission frequency. The echo wave reflected at the target has a reception frequency which is periodically frequency modulated in the same manner, there being a transit time dependent frequency difference between the transmission frequency and the reception frequency, such frequency difference being the distance frequency which is determined as measure of the distance of the target from the transmission/reception location. Using a constant reference frequency the transmission frequency and the reception frequency are converted in a common mixer to give a transmission/reception intermediate frequencies mixture, which includes a transmission intermediate frequency formed by conversion of the transmission frequency using the reference frequency, and a reception intermediate frequency formed by conversion of the reception frequency using the reference frequency. The distance frequency is determined from the frequency difference between the transmission intermediate frequency and the reception intermediate frequency, and the transmission intermediate frequency comprised in the transmission reception intermediate frequencies mixture is utilized for correction of the frequency modulation of the transmission frequency. For this purpose the arrangement for implementing the method comprises a correction channel which is connected with the output of the common mixer parallel to the measurement channel.
|
