测绘工程外文翻译文献
测绘工程外文翻译文献
(文档含中英文对照即英文原文和中文翻译)
原文:
Conversion of existing mapping results to the China
Geodetic Coordinate System 2000
China is a vast area of the country, due to historical reasons, China's adoption of the Beijing 54 coordinate system, such as Xi'an 80 coordinate system coordinates. With the mapping technology known as 2000, China established a national geodetic coordinate system of the earth coordinate system. This will be the extent possible, on China's achievements have b
测绘工程外文翻译文献
een converted to the new mapping coordinates a variety of theoretical methods to be learning from industry peers.
1.Definition of the China Geodetic Coordinate System
2000
1. National Geodetic coordinate system is defined to include the origin of coordinates, three axes of direction, scale, and the earth ellipsoid four basic parameters of the definition. China Geodetic Coordinate System origin to include the oceans and atmosphere whole Earth's center of mass; China Geodetic Coordinate System Z axis pointing to the original Epoch 2000.0 of the Earth's direction, the epoch of the point by the International Bureau of time epoch 1984.0 set the initial point for the projections, the time evolution of orientation relative to the crust does not guarantee the global residual rotation, X-axis pointing to the original point of reference Greenwich meridian and the Earth equatorial plane (epoch 2000.0) of the intersection, Y-axis and Z axis, X axis to the right hand orthogonal coordinate system. With general relativity in the sense of scale. China Geodetic Coordinate System used in the earth ellipsoid parameters values are: Long axle a＝6378137m Flat rate f=1/298.257222101
Gravitational constant GM＝3.986004418×1014m3s-2 Angular velocity ω＝7.292l15×10-5rad s-1 Other parameters as follows: Short radiusb(m) Polar radius of curvaturec (m) 6356752.31414 6399593.62586 测绘工程外文翻译文献
The first eccentricity e Squared of first eccentricity e2 Second Eccentricity e? Squared of Second Eccentricity e?2 1/4The length of the meridian circle Q(m) The average radius of ellipsoid R1(m) The same surface area of the sphere radius R2(m) The same volume of radiusR3(m) Ellipsoid in the proper position U0(m2s-2) Dynamic shape factor J2 Spherical harmonic coefficients J4 Spherical harmonic coefficients J6 Spherical harmonic coefficients J8 m??2a2b/GM 0.0818191910428 0.00669438002290 0.0820944381519 0.00673949677548 10001965.7293 6371008.77138 6371007.18092 6371000.78997 62636851.7149 0.001082629832258 -0.00000237091126 0.00000000608347 -0.00000000001427 0.00344978650678 9.7803253361 9.8321849379 9.7976432224 9.8061977695 The Equator’s value of normal gravity γe Polarized normal gravity valueγp Mean normal gravity γ Latitude45 degrees of the normal gravity valueγ45° 2. The method of Point and coordinate’s
transformation
(1) Model selection
The scope of national and provincial choose two-dimensional coordi
测绘工程外文翻译文献
nate conversion seven parameter transformation model; provincial level below the three-dimensional coordinate conversion option or four-parameter model for planar four-parameter model. For the relatively independent plane coordinate system and the China Geodetic Coordinate System links four parameters model can be used flat or polynomial regression model. Coordinate transformation model detailed in Part VI of this guide.
(2) Coincidence point selection
Coincidence coordinates can be used in the two coordinates are the results of the point coordinates. But in the end overlap point needed to determine the conversion parameters according to the calculated coincidence coordinate residuals, according to the size of the residuals to determine if the residual error is greater than 3 times removed in recalculate the coordinate conversion parameters until satisfied precision so far; used to calculate the number of transformation parameters and conversion Coincidence size of the region, but not less than five.
(3) Calculation of model parameters
Coincidence identified with the coordinates of the coordinate conversion model model parameters using least squares method.
(4)Accuracy assessment and validation.
Coordinate transformation with the above model must meet the corresponding precision indicators, specific indicators and assessment of accuracy assessment methods, see the annex to relevant content. Select some coincidence as an external check point, is not involved in conversion parameter calculation, calculating the transformation parameters using the conversion point coordinates are compared with known coordinates of the external check. Should be selected at least six evenly spaced points on the coordinate transformation coincides accuracy check.
(5) Coordinates of the midpoint of the database conversion model parameter calculation of regional selection
测绘工程外文翻译文献
Xi'an coordinate system for the 1980 database, using national data of a set of model parameters to meet the 1:5 million and 1:25 million scale database conversion accuracy; with the national data of the model parameters of the six regional meets 1 : 10 000 scale database conversion accuracy. For the 1954 Beijing coordinates database conversion, using the national data of the model parameters of the six regional meets, and 1:25 million, 1:5 million scale database conversion accuracy; by (2 ° × 3 °) to Calculation of model parameters to meet the 1:1 million scale database conversion accuracy.
3.1:2.5-1:25 Million conversion of the database
(1)Basic scale topographic maps by country Framing organization's database
Basic scale topographic maps by country sub-site organizations graphics data (DLG,DEM,DRG),based on the following program to convert.
1.1:2.5-1:10million DLG conversion of the database
(2)1954 Beijing coordinate system1:2.5-1:10 million DLG conversion of the database
A,according to the appropriate regional scale sub-division of lots, two steps complete the coordinate transformation. First to ellipsoid transform, re-scale maps using the corresponding region of X, Y coordinates of the coordinate shift amount of shift;
B,according to 2000 National Geodetic coordinates corresponding to the scale of the standard profile data and Drawing cutting edge of the region maps the data in the blank area adjacent maps use additional data;
C,add the 2000 National Geodetic coordinates in grid square layer, delete the original square grid where the data layer;