Covert WGS84GEO geographical coordinates TO HK1980GRID coordinates

Covert WGS84GEO geographical coordinates TO HK1980GRID coordinates

WGS84GEO_TO_HK1980GRID(latitude, longitude)

Arguments

latitude	latitude in decimal degrees
longitude	longitude in decimal degrees

Details

This function convert the latitude and longitude to HK80GEO coordinates first, and converts the later to HK1980GRID coordinates.

Value

N

Northern coordinate in meters

E

Eastern coordinate in meters

References

Survey & Mapping Office Lands Department, Hong Kong Government (1995). Explanatory Notes on Geodetic Datums in Hong Kong, available at: http://www.geodetic.gov.hk/smo/gsi/data/pdf/explanatorynotes.pdf

Author

Jinlong Zhang

Note

The coordinates should be within the range of Hong Kong. Providing coordinates outside Hong Kong will lead to wrong results.

See also

HK1980GRID_TO_WGS84GEO

Examples

options(digits = 15)
HK1980GRID_TO_WGS84GEO(820351.389, 832591.320)
#>           latitude        longitude
#> 1 22.3221739419203 114.141179433862
### $latitude
### [1] 22.3221739419203
### 
### $longitude
### [1] 114.141179433862

### Answer from the online conversion tool
### http://www.geodetic.gov.hk/smo/tform/tform.aspx
### 22.322172084
### 114.141187917