Convert HK80UTM coordinates to HK1980GRID coordinates

Convert HK80UTM coordinates to HK1980GRID coordinates

HK80UTM_TO_HK1980GRID(N, E, zone)

Arguments

N	Numeric, Northern coordinate in meters
E	Numeric, Eastern coordinate in meters
zone	zone, UTM zone, either 49 or 50 for Hong Kong.

Details

This function converts the coordinates to HK80GEO first, and convert the intermediate results 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_HK80UTM

Examples

#### The similar conversion is not available at 
#### http://www.geodetic.gov.hk/smo/tform/tform.aspx
#### The accuracy is unknown
options(digits = 15)
HK80UTM_TO_HK1980GRID(N = 2471279, E = 205494, zone = 50)
#>                  N                E
#> 1 820146.559739826 832856.283711548