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| author | Frank Warmerdam <warmerdam@pobox.com> | 2002-12-09 16:01:02 +0000 |
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| committer | Frank Warmerdam <warmerdam@pobox.com> | 2002-12-09 16:01:02 +0000 |
| commit | 27c197f9da8005a2fd58bb8d902beb0864a2916b (patch) | |
| tree | 84dad4b3cca6d7e2adc3ce71333f432b22dd323c /html | |
| parent | f8e9a822d7e9166b9925f75ba36bb7aa75afc3c1 (diff) | |
| download | PROJ-27c197f9da8005a2fd58bb8d902beb0864a2916b.tar.gz PROJ-27c197f9da8005a2fd58bb8d902beb0864a2916b.zip | |
added prime meridian support
git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1041 4e78687f-474d-0410-85f9-8d5e500ac6b2
Diffstat (limited to 'html')
| -rw-r--r-- | html/gen_parms.html | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/html/gen_parms.html b/html/gen_parms.html index 045eecf6..bc59b116 100644 --- a/html/gen_parms.html +++ b/html/gen_parms.html @@ -1,4 +1,4 @@ -<html> +w<html> <head> <title>PROJ.4 - General Parameters</title> </head> @@ -20,6 +20,47 @@ Virtually all coordinate systems allow for the presence of a false easting meters even if the coordinate system is some other units. Some coordinate systems (such as UTM) have implicit false easting and northing values.<p> +<h2><a name="pm">pm - Prime Meridian</a></h2> + +A prime meridian may be declared indicating the offset between the prime +meridian of the declared coordinate system and that of greenwich. A prime +meridian is clared using the "pm" parameter, and may be assigned a symbolic +name, or the longitude of the alternative prime meridian relative to +greenwich. <p> + +Currently prime meridian declarations are only utilized by the +pj_transform() API call, not the pj_inv() and pj_fwd() calls. Consequently +the user utility <b>cs2cs</b> does honour prime meridians but the <b>proj</b> +user utility ignores them. <p> + +The following predeclared prime meridian names are supported. These +can be listed using the cs2cs argument <b>-lm</b>.<p> +<pre> + greenwich 0dE + lisbon 9d07'54.862"W + paris 2d20'14.025"E + bogota 74d04'51.3"E + madrid 3d41'16.48"W + rome 12d27'8.4"E + bern 7d26'22.5"E + jakarta 106d48'27.79"E + ferro 17d40'W + brussels 4d22'4.71"E + stockholm 18d3'29.8"E + athens 23d42'58.815"E + oslo 10d43'22.5"E +</pre> + +Example of use. The location long=0, lat=0 in the greenwich based +lat/long coordinates is translated to lat/long coordinates with Madrid +as the prime meridian. <p> + +<pre> + cs2cs +proj=latlong +datum=WGS84 +to +proj=latlong +datum=WGS84 +pm=madrid +0 0 <i>(input)</i> +3d41'16.48"E 0dN 0.000 <i>(output)</i> +</pre> + <h2><a name="towgs84">towgs84 - Datum transformation to WGS84</a></h2> Datum shifts can be approximated by 3 parameter spatial translations (in |