Analysis Of Refractive Error In The Troposphere

With the increasing demand of the precision of various radio tracking systems, refractive correction methods are also continuously improved. From the initial method (equivalent earth radius method) to the present general method (radial tracking method), all of them are can't satisfy the increasing demand for the precision. Therefore, the research of radio refractive correction methods is the key of improving the precision of various radio tracking systems.The prerequisite of radio refractive correction is the space-time characteristic and model of the refractive index, main space variation of which is represented by the spherical stratified model, with uneven characteristic in the level and random uneven characteristic of the turbulence in the meantime, and main time variation of which is represented by the changes in the year, season, day and night. Beause of the stable statistics characteristic of refractive index model, the correction is based on the average distributed model, under the condition of common precision, such as the linear model, the index model, the tridivision model and so on. But in the the condition of very high precision, those methods aren't fit, it need to get the sectional drawing of refractive index by measured data in real time and on the spot.The paper is drawed by many important theories and technologies. First, atmospheric structure and characteristic of the troposphere are introduced in the paper. Then, the relationship between meteorological parameters and refractive index in the troposphere is analyzed. In the following, the refractive effect and the refractive index model in the troposphere is elaborated. Then, based on the spherical stratified model, the model of troposphere refractive index in the region of Chengdu is builded, and the refractive error charts are shown. Next, the refractive error is corrected by some simple correcting methods, like equivalent earth radius method,...