1、附录 A VERTICAL ATMOSPHERIC REFRACTION COEFFICIENT TO DETERMINE NEW WAYS OF FRIST.interoduction A long time, trigonometric leveling observations in many types of geodetic measurement concept is considered a class of low precision, the reason for this is because of the vast numbers of measurements so f
2、ar have not found work well to eliminate the impact of a trigonometric leveling a major factor in the accuracy of the methods and measures, thus limiting this approach in the elevation measurement. We know that, in addition to observational error, the impact of trigonometric leveling is a major fact
3、or in the accuracy of the vertical atmospheric refraction and vertical deviation, when the distance is longer, the accuracy of trigonometric leveling is mainly affected by the effects of atmospheric refraction vertical. Therefore,Many workers have long been measured in the study to determine the ver
4、tical atmospheric refraction coefficient method. Long-term studies have shown that analysis of radio field as a result of the atmosphere of time and space with the rapidly changing, especially in recent changes in surface temperature gradient is very large, in order to establish a universal and prac
5、tical model to eliminate or accurate atmospheric correction of the effects of the vertical refractive index is very difficult and even almost impossible. In recent years, with the continuous development of measuring instruments and updating, especially the precision range finder trigonometric leveli
6、ng in the application, causing a number of scholars on the refractive index of Geodesy more in-depth research. SECOND, atmospheric vertical refraction coefficient We know that the density of light through the medium non-uniform refraction will occur, so that light into a complex of both curvature an
7、d torsion of space curves. In the survey, because the temperature in time and space changes in the density of the atmosphere have also taken place in time and space changes, so the speed of light waves, amplitude, phase and propagation direction are randomly generated impact. In light of such proper
8、ties, it is difficult to even make it almost impossible to use a general model useful to describe the light in。 This gas properties. On a particular area, the atmospheric density in a variety of different conditions, differences arising from the need to use ECTerms to describe the law, the same toke
9、n, the vertical atmospheric refraction coefficient is also necessary to determine the statistical laws. The emergence of the phenomenon of refraction, which was mainly due to light through the atmosphere because of uneven density, the non-uniformity are mainly distributed in the vertical direction,
10、with a wavelength of light shot out of the atmosphere, in the final analysis is the condition of the atmospheric density of the . Trigonometric leveling refraction of the impact can be attributed to atmospheric refraction on the vertical angle vertical or zenith distance observations of the effects
11、of atmospheric refraction effects of the vertical real-time field is always inevitably included in the vertical angle or zenith distance of the actual observations in.Therefore, the impact is always in the vertical angle or zenith distance observations of changes in size and directly reflected to th
12、e same function and form of participation in the calculation, which have an impact. Third, determine the atmospheric vertical refraction coefficient method At present, the determination of atmospheric refraction coefficient vertical approach more, past and present, many scholars have conducted resea
13、rch, given Refraction correction model for many, but these formulas are basically the use of meteorological elements measured refraction coefficient calculation, requiring a high degree of Angle measured at the same time observing a large number of meteorological data, it cost more, in practical wor
14、k, using less. In this paper, the vertical atmospheric refraction coefficient as random parameters, in the adjustment together with the solution of the main parameters. The selection of the parameters measured in accordance with the geographical area the case may be, you can set up a parameter regio
15、n can also be set up district election. The adjustment in this model, each station used to set a parameter to determine the method of measuring the average of the refraction coefficient. FOURH. Example An example is a triangle with 13-point elevation of the triangular control net (Network Tulio), in
16、 the surveyed area, O is known to its point, the set of the points of vertical deflection relative to zero, that is the point of gravity direction and the corresponding ellipsoid of the normal surface direction. In the example, because of the distance has reached the mm-level observations, we assume
17、 that there being no error in the adjustment does not consider its impact. The example of field work is carried out in June, is T3 theodolite measuring instruments, allowed the goal is to cross-foot base, the base apparatus and horizontal feet are put in the cement column 1.20m high. A total of 13 s
18、pecific points, 39 edges, and each side are at the same time of the observation, Vertical angle measurement using four back, observing the 9 hours of 17:00 a. 1. Atmospheric refraction coefficient of the approximation used to identify examples of this type to determine the refractive index of each s
19、ide of the approximation coefficients (rounded down to the nearest K negative value), and then calculated for each of the approximate average station. 2. Observing the right to determine the elevation difference Determined by trigonometric leveling the elevation, the accuracy with the side length va
20、ries, the longer the length, the greater the error, the lower accuracy, and secondly, to the observation of one-way observation elevation and elevation difference accuracy is not the same .In the network adjustment, in order to distinguish between the accuracy of elevation differences, on the need to determine the elevation of the right of observation.
