Research On Pointing Accuracy Stability Of Vehicle-borne Photo-electronic Theodolite

With the rapid development of the aviation industry and the need for long-rangetarget detection, the requirements of pointing accuracy and mobility of the newtheodolite are also increasing. In order to meet the needs of motorized tracking andmeasurement, the development of the traditional fixed optical measurementequipment to the direction of motion platform. This article based on a motionplatform optical measurement equipment-vehicle-borne photo-electronic theodolite,discussed the error factors of the pointing accuracy and the stability,and using themeasured data for experimental verification, proved the correctness of this article.Pointing accuracy as an important technical indicators for theodolite, because ofthe factors of the machinery manufacturing, machining assemble, use error, encodererror, atmospheric refraction error and deformation error, so there are some errors inthe theodolite, there for the pointing accuracy of the theodolite are reduced. Whenthe theodolite working for a long time, the vehicle platform and structure will have adeformation because of the changes in environmental temperature, this willinfluence the pointing accuracy and stability of the theodolite.First, this article analysis the main errors which influence the pointing accuracyof the theodolite, and using the theory of the coordinate transformation, derivationthe error formula of vertical axis tilt caused by vehicle platform deformation andhorizontal axis tilt,sighting axis tilt caused by ctructure deformation. Secondly, usingthe star data, compare and analysis three model of the pointing error correction,concluded that the structure model was the best model for currently. Then, in the realenvironment, using the electronic level and temperature sensor measuring the oneday deformation of platform and the temperature in different parts of the structure,and using Matlab and Ansys Workbench12.0calculated the deformation of theplatform and structure. The last, analysis the influence of deformation to the pointingaccuracy which caused by temperature changes, and conducted an experimental verification for vertical axis tilt, proved that compensating the errors caused bydeformation, it can ensure that the theodolite can have a long-period and stabilitypointing accuracy.