Convert WGS84GEO coordinates to HK80GEO coordinates

WGS84GEO_TO_HK80GEO(latitude, longitude)

Arguments

latitude	latitude in decimal degrees
longitude	longitude in decimal degrees

Details

This function uses the simplified relationship between WGS84GEO and HK80GEO. See Page C4 on the explanatory note.

Value

latitude

latitude in decimal degrees

longtitude

longitude in decimal degrees

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.

Examples

options(digits = 15)
WGS84GEO_TO_HK80GEO(22.322172084,    114.141187917)
#>           latitude        longitude
#> 1 22.3236998617778 114.138743472556
#### $latitude
#### [1] 22.3236998617778
#### 
#### $longitude
#### [1] 114.138743472556

#### Answer from the online conversion tool
#### http://www.geodetic.gov.hk/smo/tform/tform.aspx
#### 22.323701767,  114.138734989