First, the type of rangefinder error
The infrared rangefinder has the advantages of high degree of automation, fast ranging speed and high accuracy. However, if the instrument is used improperly or poorly maintained, the performance of the instrument may change early, resulting in reduced accuracy. The aging of electronic components is also an important reason for the decrease in the accuracy of the instrument and the change in the instrument constant. In order to grasp the performance indicators of each instrument, use the instrument reasonably, and measure high-quality data, the instrument must be fully tested regularly.
There are many errors in ranging, including aiming error, amplitude and phase error, centering error, period error, and error caused by signal-to-noise ratio. There are occasional errors and systematic errors. Although the aiming errors are accidental, they also have certain regularity. A good surveyor should know the performance of the instrument he has, so that he can use the instrument to observe in the smallest error area of the instrument.
Second, the generation of rangefinder aiming error
Aiming error refers to the inconsistency of the distance measurement results when different positions of the beam emitted by the rangefinder are used for measurement, and the distance measurement deviation, that is, the error of the uneven phase of the light-emitting tube or the modulator, is mainly due to GaAs ) Caused by uneven phase of the light beam from the LED. The beam emitted by gallium arsenide is ideally in the same range as the arc tube on the curved surface with the same phase. Similarly, the distance measured using any position of the light beam is also the same, but it is not the case. The phase of each point on the curved surface equidistant from the arc tube is not the same, and the phase with the same phase is an irregular curved surface. In order to use different positions of the beam to measure distance, the results obtained are different. The difference between the two is the aiming error caused by the uneven phase.
Calibration of the rangefinder
From the isophase curve and isointensity curve, it can be seen that the aiming error distribution is more uniform, but in order to improve the observation accuracy better, when aiming the prism, aim at the part with the smallest error-the best area. In order to reduce the aiming error, on the one hand, it is necessary to improve the manufacturing process of the modulator or the luminous tube and improve the uniformity of its spatial phase. Taking into account that the cause of the assured deflection of the aim is caused by the telescope's aiming error and the transmitting and receiving optical axes are not parallel to the telescopic collimation axis. The former is accidental and the latter is systematic. Therefore, when using the instrument, the parallelism of the three axes should be checked and corrected frequently to find the best observation area in order to improve the observation accuracy.