Transverse Mercator Parameters

Hi

have a map I want to use with Orux Maps which uses Transverse Mercator projection. I converted the image from ECW to PNG so OruxMaps Desktop can use it using Gdal.

Code:

$ gdalinfo sk5521.ecw
Driver: ECW/ERDAS Compressed Wavelets (SDK 3.x)
Files: sk5521.ecw
Size is 6377, 9197
Coordinate System is:
PROJCS["MGA55",
    GEOGCS["GEOCENTRIC DATUM of AUSTRALIA",
        DATUM["GDA94",
            SPHEROID["GRS80",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",147],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",10000000],
    UNIT["Meter",1]]
Origin = (452046.125000000000000,5666193.879999999888241)
Pixel Size = (31.750000000000000,-31.750000000000000)
Corner Coordinates:
Upper Left  (  452046.125, 5666193.880) (146d26'42.07"E, 39d 9' 7.69"S)
Lower Left  (  452046.125, 5374189.130) (146d25'22.55"E, 41d46'57.72"S)
Upper Right (  654515.875, 5666193.880) (148d47'16.37"E, 39d 8'23.07"S)
Lower Right (  654515.875, 5374189.130) (148d51'32.38"E, 41d46' 8.78"S)
Center      (  553281.000, 5520191.505) (147d37'42.59"E, 40d28' 2.08"S)
Band 1 Block=6377x1 Type=Byte, ColorInterp=Red
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287
Band 2 Block=6377x1 Type=Byte, ColorInterp=Green
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287
Band 3 Block=6377x1 Type=Byte, ColorInterp=Blue
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287

When I select the projection 'Transverse Mercator' I am asked for 5 parameters.

1. Should I just fill in the parameters as shown below?
   
2. What is 'k'?

Code:

Latitude Origin: 452046.125000000000000
Longitude Origin: 5666193.879999999888241
k: ??????????
False East: 500000
False North: 10000000

Cheers
Richard

r1chard wrote:Hi

have a map I want to use with Orux Maps which uses Transverse Mercator projection. I converted the image from ECW to PNG so OruxMaps Desktop can use it using Gdal.

Code:

$ gdalinfo sk5521.ecw
Driver: ECW/ERDAS Compressed Wavelets (SDK 3.x)
Files: sk5521.ecw
Size is 6377, 9197
Coordinate System is:
PROJCS["MGA55",
    GEOGCS["GEOCENTRIC DATUM of AUSTRALIA",
        DATUM["GDA94",
            SPHEROID["GRS80",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",147],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",10000000],
    UNIT["Meter",1]]
Origin = (452046.125000000000000,5666193.879999999888241)
Pixel Size = (31.750000000000000,-31.750000000000000)
Corner Coordinates:
Upper Left  (  452046.125, 5666193.880) (146d26'42.07"E, 39d 9' 7.69"S)
Lower Left  (  452046.125, 5374189.130) (146d25'22.55"E, 41d46'57.72"S)
Upper Right (  654515.875, 5666193.880) (148d47'16.37"E, 39d 8'23.07"S)
Lower Right (  654515.875, 5374189.130) (148d51'32.38"E, 41d46' 8.78"S)
Center      (  553281.000, 5520191.505) (147d37'42.59"E, 40d28' 2.08"S)
Band 1 Block=6377x1 Type=Byte, ColorInterp=Red
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287
Band 2 Block=6377x1 Type=Byte, ColorInterp=Green
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287
Band 3 Block=6377x1 Type=Byte, ColorInterp=Blue
  Overviews: 3188x4598, 1594x2299, 797x1149, 398x574, 199x287

When I select the projection 'Transverse Mercator' I am asked for 5 parameters.

1. Should I just fill in the parameters as shown below?
   
2. What is 'k'?

Code:

Latitude Origin: 452046.125000000000000
Longitude Origin: 5666193.879999999888241
k: ??????????
False East: 500000
False North: 10000000

Cheers
Richard

Hi, Richard;

You have to use:

PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",147],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",500000],
PARAMETER["false_northing",10000000],

lat origin --> 0
lon origin --> 147
k-->0.9996
false east --> 500000
false north --> 10000000

orux

Thanks!