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wrote:
You need to know at least the name of the projection and various
parameters that are specific to the grid you are using. You might be
able to find the projection by looking at www.epsg.org; that has a
directory of projections and parameters in use in various parts of
the world. Once you've found that, a software package called "proj"
will allow you to do the conversions - it's a command-line program,
but it is very effective.
Paul Cooper
>I have got X,Y coordinates in a local metric system, of which I know:
>- origin (0,0) gps coordinates
>- angle between the Y axis and the North
>Can you give me any web site about which you're talking that can help
>me solving this problem?
>- origin (0,0) gps coordinates
>- angle between the Y axis and the North
>Can you give me any web site about which you're talking that can help
>me solving this problem?
You need to know at least the name of the projection and various
parameters that are specific to the grid you are using. You might be
able to find the projection by looking at www.epsg.org; that has a
directory of projections and parameters in use in various parts of
the world. Once you've found that, a software package called "proj"
will allow you to do the conversions - it's a command-line program,
but it is very effective.
Paul Cooper
> > You =A0can refer =A0to a couple =A0 of =A0websites =A0to get =A0it done=
, some C
> > source codes are =A0also posted that can do the job . But it really
> > depends on the location of the co-ordinates , datum , projection
> > because the method of conversion varies depending on each of them.
> > depends on the location of the co-ordinates , datum , projection
> > because the method of conversion varies depending on each of them.
> I have got X,Y coordinates in a local metric system, of which I know:
> - origin (0,0) gps coordinates
> - angle between the Y axis and the North
> Can you give me any web site about which you're talking that can help
> me solving this problem?
> - origin (0,0) gps coordinates
> - angle between the Y axis and the North
> Can you give me any web site about which you're talking that can help
> me solving this problem?
If you know the exact lat and lon of your origin, then you can compute
everything that you need using great circles.
Proj.4 has very accurate great circle calculations (assuming that you
have or can compute an accurate distance and direction to each point
of interest from your known origin). See, for instance:
http://trac.osgeo.org/proj/wiki/man_geod
Home page:
http://trac.osgeo.org/proj/wiki
> > > You =A0can refer =A0to a couple =A0 of =A0websites =A0to get =A0it do=
ne , some C
> > > source codes are =A0also posted that can do the job . But it really
> > > depends on the location of the co-ordinates , datum , projection
> > > because the method of conversion varies depending on each of them.
> > > depends on the location of the co-ordinates , datum , projection
> > > because the method of conversion varies depending on each of them.
> > I have got X,Y coordinates in a local metric system, of which I know:
> > - origin (0,0) gps coordinates
> > - angle between the Y axis and the North
> > Can you give me any web site about which you're talking that can help
> > me solving this problem?
> > - origin (0,0) gps coordinates
> > - angle between the Y axis and the North
> > Can you give me any web site about which you're talking that can help
> > me solving this problem?
> If you know the exact lat and lon of your origin, then you can compute
> everything that you need using great circles.
> Proj.4 has very accurate great circle calculations (assuming that you
> have or can compute an accurate distance and direction to each point
> of interest from your known origin). =A0See, for instance:http://trac.osg=
eo.org/proj/wiki/man_geod
> everything that you need using great circles.
> Proj.4 has very accurate great circle calculations (assuming that you
> have or can compute an accurate distance and direction to each point
> of interest from your known origin). =A0See, for instance:http://trac.osg=
> Home page:http://trac.osgeo.org/proj/wiki
The reference system I'm using is not a "standard" system, it is
"local", developed for referring objects respect its origin.
I was able to transform local X,Y meters coordinates using the "Lat/
lon given radial and distance" formula:
http://williams.best.vwh.net/avform.htm#LL
- Opinion about buying a Gps
- Garmin GPS
- 2009-12-15
>> source codes are also posted that can do the job . But it really
>> depends on the location of the co-ordinates , datum , projection
>> because the method of conversion varies depending on each of them.