The Research And Produce Of Using Super Long Baseline To Calibrate Invar Wire

With development of science, mapping devices are going to be high precise andautomatic, and the traditional invar baseline wire still has its position because it hasstrong points such as stable data result, reliability, anti-disturbance from outside etc.compared with electronic total station or laser range finder at the precise measurementof long distance in countryside. But present domestic invar baseline wire can onlycalibrate below24m because of limitation of baseline length.This project comes from the project of “Application and Extension Research of50m Super Long Baseline” from General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China which bases on the superlong baseline platform built by Shanghai Institute of Measurement and TestingTechnology. This project aims at solving the problem of weak signals and unstablereading of dual frequency laser interferometer which happen at the calibration of invarbaseline wire because of environment condition of super long baseline laboratory,meanwhile also solving the problem of no necessary supporting device of calibrationinvar baseline wire to original super long baseline, after analyzing the technicaldevelopment of dual frequency interferometer and strong and weak points of presentsuper long baseline. This project designs the schemes of solving laboratoryenvironment problems and main calibration supporting equipment of invar baselinewire, and also completes calibration of large range invar wire under the condition ofonce assembly in order to avoid sector by sector measurement in the condition ofshortage of long guide way.This project completes following items.(1) Analyzed engineering technical difficulties of precision control ofenvironment temperature and humidity of large spacious laboratory and gave schemeof sector by sector control of temperature and humidity, meanwhile gave how to makelaboratory to meet environment requirements by the cleansing way etc., in thecondition of which environment of original50m super long baseline laboratory islower than the calibration requirements.(2) Designed a set of optical imaging system on air floating slider of super longbaseline using industrial camera, which can solve scale aiming problem at the calibration of invar baseline wire.(3) Designed and made supporting plane boss structure and fixed rolling wheeltension structure of invar baseline wire to support invar baseline wire while it is beenexpanded at the calibration of invar baseline wire.(4) Designed temperature sensor supporting system and suspension bracket ofsupporting temperature compensation and correction sensors, and completed real timeobservation of temperature compensation of dual frequency laser range finder systemin order to improve precision of calibrating data.(5) Designed and made three digital display panel in order to make laboratorystuff to real time observe dual frequency data of laser interferometer.This project gives full proofs that the whole device meets design requirements ofproject completely through validation of testing data and assessment of the stability,repeatability and accuracy of the whole device and analysis of related measurementuncertainty assessment on the base of completing design scheme, engineeringrebuilding and hardware design. It also states the application and extension researchof super long baseline to the other appliances.