Ranging method for real-time compensation of common link air refractive index

Abstract

The invention discloses a ranging method for real-time compensation of a common link air refractive index. The ranging method comprises the steps that femtosecond pulse fundamental frequency light isgenerated by a femtosecond optical frequency comb and transmitted to a frequency doubling unit, and thus frequency doubling light is generated through the frequency doubling unit; the fundamental frequency light is divided by a beam splitter into two paths of light beams which enter a reference light path and a measurement light path correspondingly, and the frequency doubling light is divided bythe beam splitter into two paths of light beams which enter the reference light path and the measurement light path correspondingly; the repetition frequency of the femtosecond optical frequency combis adjusted, the fundamental frequency light and the frequency doubling light obtain a first rough measuring distance and a second rough measuring distance through a time-of-flight method correspondingly, and the fundamental frequency light and the frequency doubling light obtain first accurate measuring distance and a second accurate measuring distance through an interference method correspondingly; and dispersion scale factors of the fundamental frequency light and the frequency doubling light are calculated, and the compensation distance of air refractive index compensation is calculated and obtained according to the first accurate measuring distance and the second accurate measuring distance. According to the ranging method, the influence of the air refractive index on the ranging precision is solved by measuring the optical distance corresponding to the two wavelengths.

Description

technical field [0001] The present invention relates to the technical field of femtosecond optical frequency combs, in particular to a real-time compensation ranging method for common-link air refractive index. Background technique [0002] As a cutting-edge technology, femtosecond optical frequency comb can be directly traced to the time reference, so its application in the field of distance measurement has excellent development prospects, and has the advantages of high measurement accuracy and long measurement distance. [0003] In practical applications, the ranging accuracy of the femtosecond optical frequency comb will be affected by the refractive index of the air in the use environment, and the air refractive index will change the propagation speed of the femtosecond optical frequency comb. The existing methods for measuring the refractive index of air and compensating for ranging accuracy are mainly direct methods. The direct method obtains the measured air refractiv...

AI Technical Summary

Problems solved by technology

The existing methods for measuring the refractive index of air and compensating for ranging accuracy are mainly direct methods. The direct method obtains the measured air refractive index value by arranging a certain number of sensors, and compensates the ranging results after averaging calculations. Although it can be achieved by Arrange more measurement points to improve the air refractive index measurement accuracy, but it is still unable to realize the air refractive index compensation of the whole path

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