Convert the HK80GEO coordinates to HK1980GRID coordinates

Convert the HK80GEO coordinates to HK1980GRID coordinates

HK80GEO_TO_HK1980GRID(latitude, longitude)

Arguments

latitude	latitude in decimal degrees
longitude	longitude in decimal degrees

Details

This functions uses equation 1,2,3 in the explanatory note (page C9) to convert the HK80GEO coordinates into 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_HK80GEO

Examples

options(digits = 15)
HK1980GRID_TO_HK80GEO(820351.389, 832591.320)
#>           latitude        longitude
#> 1 22.3237017196981 114.138734989417
#### $latitude
#### [1] 22.3237017196981
#### 
#### $longitude
#### [1] 114.138734989417

####  Answer from the online conversion tool
### 22.323701767
### 114.138734989