GB/T 17943-2025Specification for astrogeodetic surveying (English PDF)

3.1

The theory and method of determining the astronomical longitude, latitude and azimuth of a point on the ground by observing the celestial coordinate position of a celestial body at a certain moment.

Note. Geodetic and astronomical surveying is mainly used for ground reference system orientation, vertical deviation determination, engineering orientation and plane survey control network direction error control.

The tasks include. determining vertical deviation for establishing national and regional geoid models; providing orientation parameters for establishing ground coordinate systems;

It provides a directional reference for engineering construction and a azimuth reference for calibrating the geographic meridian at a specified location.

3.2

The Jet Propulsion Laboratory of the United States compiled the data based on ground-based optical and radio technology and the orbits of spacecraft around celestial bodies in the solar system.

The solar system ephemeris includes the parameters of the position, speed, mass, shape and attitude of the sun, moon, earth and various planets.

Note. In.1997, the International Astronomical Union (IAU) designated the DE405 ephemeris as the dynamical realization of the International Celestial Reference System.

3.3

The total station electronic tachometer is used to measure the time and altitude angle of stars evenly distributed in each quadrant passing through the approximate contour circle to determine the astronomical

Longitude, latitude method.

3.4

A method of observing the North Star (star) and recording the clock time to determine the sidereal hour angle and obtain the astronomical azimuth of the ground target.

3.5

A digital camera that is composed of an optical telescope, an imaging device, a precision inclinometer, a rotating platform, etc., and is used to take images of stars at the zenith of the station.