US 11,754,713 B2
Range finding apparatus and control method
Hidemi Noguchi, Tokyo (JP); and Junichi Abe, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 16/762,492
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Dec. 5, 2018, PCT No. PCT/JP2018/044683
§ 371(c)(1), (2) Date May 7, 2020,
PCT Pub. No. WO2019/116980, PCT Pub. Date Jun. 20, 2019.
Claims priority of application No. 2017-240773 (JP), filed on Dec. 15, 2017.
Prior Publication US 2021/0041561 A1, Feb. 11, 2021
Int. Cl. G01S 17/36 (2006.01); G01S 7/487 (2006.01); G01S 17/10 (2020.01); G01S 17/87 (2020.01); G01S 17/32 (2020.01)
CPC G01S 17/36 (2013.01) [G01S 7/487 (2013.01); G01S 17/10 (2013.01); G01S 17/32 (2013.01); G01S 17/87 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A range finding apparatus comprising:
a first processor to generate a plurality of range finding signals, wherein at least two of the range finding signals are used in range finding methods that are different from one another;
a modulator to generate a modulation signal by adding a training signal before each of the generated range finding signals, and to generate transmission light by performing a combination of quadrature modulation and polarization modulation on an optical carrier wave by using each of the generated range finding signals and by using the training signal, wherein the combination used in generating the transmission light for each generated range finding signal is different;
a first optics to transmit the generated transmission light;
second optics to receive, as reflection light, the transmission light as reflected by an object to be measured; and
a second processor to extract reception signals respectively corresponding to the range finding signals by demodulating the reflection light by using the training signal included in the reflection light, to compute a distance to be measured by using any one or more of the extracted reception signals, to determines a parameter to be used for polarization separation or quadrature demodulation by using the reflection light in a period in which the training signal is included, and to perform the polarization separation or the quadrature demodulation on the reflection light in the period including the range finding signal by using the determined parameter.