1. If the national unified 3-degree zone projection is adopted and the longitude of any local point is known as L, the formula for calculating the 3-degree zone number n where it is located first is:
N = int(L/3 +0.5)。 Note: int () is an integer function in EXCEL, that is, it directly intercepts integer bits.
Knowing the serial number of the local 3-degree belt, calculate the longitude L0 of the central meridian of the local 3-degree belt, and the formula is: L0 = 3n.
2. If the national unified 6-degree band projection is adopted, and the longitude of any local point is known as L, the formula for calculating the number n of 6-degree bands where it is located first is:
N=int((L+3)/ 6 +0.5)。 Note: int () is an integer function in EXCEL, that is, it directly intercepts integer bits.
Knowing the serial number of the local 6-degree belt, calculate the longitude L0 of the central meridian of the local 6-degree belt, and the formula is: L0= 6N-3.
3. If local coordinates are used, it is recommended to consult the local surveying and mapping qualification unit or the administrative department of surveying and mapping to see whether the local coordinate system adopts 3-degree central meridian or 6-degree belt, or adopts specific meridian for projection.
Extended data:
RTK system is mainly composed of a reference station, several mobile stations and data communication system. In RTK working mode, the reference station transmits its observation values and station coordinate information to the rover station through the data link.
The mobile station not only receives the data from the reference station through the data link, but also collects the GPS observation data, and forms differential observation values in the system for real-time processing, giving centimeter-level positioning results, which takes less than1s.
With the appearance of GPS technology and the wide application of RTK positioning technology, digital mapping with GPS RTK positioning technology can make up for the limitation of the control range of the station. In digital mapping, the combination of GPS RTK positioning technology and total station operation can not only avoid the layout of control network, but also greatly improve the efficiency and accuracy of mapping and achieve good results.
Baidu encyclopedia-central meridian