PROJ.4 and local coordinate systems

[joeri.theelen]

Hi,

Is it possible to use PROJ.4 or any of its related tools to transform coordinates from a local carthesian system into another local carthesian system (thus both are not earth related).

I inherit lots of datasets in many different formats for an archaeological site, with coordinates measured in two different local systems (shift in time). I managed to get the transformation parameters to transform sets of coordinates between both systems, with minor error. By transformation, I mean translation, rotation and dilation (scale factor) of the X/Y coordinates only, not height.

I also managed to get the transformation parameters from both local systems to the UTM system in use in that area. Thus, transforming from local to UTM to local would be an option as well.

Can anybody help me with this? I know programming such a tranformation would be trivial, but I need the power and flexibility of a tool like "cs2cs" to cope with the many different formats I am facing.

Thank you,
Joeri

[Maciej Sieczka - old]

joeri.theelen pisze:

> Is it possible to use PROJ.4 or any of its related tools to transform
> coordinates from a local carthesian system into another local carthesian
> system (thus both are not earth related).
>
> I inherit lots of datasets in many different formats for an archaeological
> site, with coordinates measured in two different local systems (shift in
> time). I managed to get the transformation parameters to transform sets of
> coordinates between both systems, with minor error. By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.
>
> I also managed to get the transformation parameters from both local systems
> to the UTM system in use in that area. Thus, transforming from local to UTM
> to local would be an option as well.
>
> Can anybody help me with this? I know programming such a tranformation would
> be trivial, but I need the power and flexibility of a tool like "cs2cs" to
> cope with the many different formats I am facing.

Joeri,

As *it seems* there is no such functionality in PROJ, maybe you would be
ineterested in GRASS v.transform [1] module. You can load ASCII data
into GRASS with v.in.ascii.

[1]http://grass.osgeo.org/grass64/manuals/html64_user/v.transform.html

Maciek

--
Maciej Sieczka
www.sieczka.org
_______________________________________________
Proj mailing list
Proj@...
http://lists.maptools.org/mailman/listinfo/proj

[support.mn]

Hello,

> By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.

there is the possibility to use datums. What you just wrote is a datum
definition. You define a datum for both systems relative to the wgs84
and proj-4 should automatically transform your coordinates.. ??

if the coordinate values do not match to any standard, just define your
own false easting and false northing values so that the resulting values
are better.. ??

Regards: Janne.

-------------------------------------

"joeri.theelen" <joeri.theelen@...> kirjoitti:

>
> Hi,
>
> Is it possible to use PROJ.4 or any of its related tools to transform
> coordinates from a local carthesian system into another local carthesian
> system (thus both are not earth related).
>
> I inherit lots of datasets in many different formats for an archaeological
> site, with coordinates measured in two different local systems (shift in
> time). I managed to get the transformation parameters to transform sets of
> coordinates between both systems, with minor error. By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.
>
> I also managed to get the transformation parameters from both local systems
> to the UTM system in use in that area. Thus, transforming from local to UTM
> to local would be an option as well.
>
> Can anybody help me with this? I know programming such a tranformation would
> be trivial, but I need the power and flexibility of a tool like "cs2cs" to
> cope with the many different formats I am facing.
>
> Thank you,
> Joeri
> --
> View this message in context: http://www.nabble.com/PROJ.4-and-local-coordinate-systems-tp18943556p18943556.html
> Sent from the PROJ.4 mailing list archive at Nabble.com.
>
> _______________________________________________
> Proj mailing list
> Proj@...
> http://lists.maptools.org/mailman/listinfo/proj
>

_______________________________________________
Proj mailing list
Proj@...
http://lists.maptools.org/mailman/listinfo/proj

[joeri.theelen]

Maciek,

Thanks for the tip: I do not use GRASS (yet), but I looked for a similar transform module in SAGA GIS and found it. The module does what I need to transform my files containing shapes in different formats.

Kind regards,
Joeri

Maciej Sieczka wrote:

joeri.theelen pisze:

> Is it possible to use PROJ.4 or any of its related tools to transform
> coordinates from a local carthesian system into another local carthesian
> system (thus both are not earth related).
>
> I inherit lots of datasets in many different formats for an archaeological
> site, with coordinates measured in two different local systems (shift in
> time). I managed to get the transformation parameters to transform sets of
> coordinates between both systems, with minor error. By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.
>
> I also managed to get the transformation parameters from both local systems
> to the UTM system in use in that area. Thus, transforming from local to UTM
> to local would be an option as well.
>
> Can anybody help me with this? I know programming such a tranformation would
> be trivial, but I need the power and flexibility of a tool like "cs2cs" to
> cope with the many different formats I am facing.

Joeri,

As *it seems* there is no such functionality in PROJ, maybe you would be
ineterested in GRASS v.transform [1] module. You can load ASCII data
into GRASS with v.in.ascii.

[1]http://grass.osgeo.org/grass64/manuals/html64_user/v.transform.html

Maciek

--
Maciej Sieczka
www.sieczka.org
_______________________________________________
Proj mailing list
[e-mail]
http://lists.maptools.org/mailman/listinfo/proj

[joeri.theelen]

Janne,

Thanks for trying to help me out. Working with datum definitions is what I tried to avoid in the first place, as I thought it would be too complex and not accurate anough for the kind of data I am working with (high precision and very large scale). Following the advise from another reply to my question, I found a module to transform coordinates from one system to another (in SAGA GIS). This has nothing to do with "real" coordinate transformations, but it is exacly what I need.

Kind regards,
Joeri

support.mn wrote:

Hello,

> By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.

there is the possibility to use datums. What you just wrote is a datum
definition. You define a datum for both systems relative to the wgs84
and proj-4 should automatically transform your coordinates.. ??

if the coordinate values do not match to any standard, just define your
own false easting and false northing values so that the resulting values
are better.. ??

Regards: Janne.

-------------------------------------

"joeri.theelen" <[e-mail]> kirjoitti:
>
> Hi,
>
> Is it possible to use PROJ.4 or any of its related tools to transform
> coordinates from a local carthesian system into another local carthesian
> system (thus both are not earth related).
>
> I inherit lots of datasets in many different formats for an archaeological
> site, with coordinates measured in two different local systems (shift in
> time). I managed to get the transformation parameters to transform sets of
> coordinates between both systems, with minor error. By transformation, I
> mean translation, rotation and dilation (scale factor) of the X/Y
> coordinates only, not height.
>
> I also managed to get the transformation parameters from both local systems
> to the UTM system in use in that area. Thus, transforming from local to UTM
> to local would be an option as well.
>
> Can anybody help me with this? I know programming such a tranformation would
> be trivial, but I need the power and flexibility of a tool like "cs2cs" to
> cope with the many different formats I am facing.
>
> Thank you,
> Joeri
> --
> View this message in context: http://www.nabble.com/PROJ.4-and-local-coordinate-systems-tp18943556p18943556.html
> Sent from the PROJ.4 mailing list archive at Nabble.com.
>
> _______________________________________________
> Proj mailing list
> [e-mail]
> http://lists.maptools.org/mailman/listinfo/proj
>

_______________________________________________
Proj mailing list
[e-mail]
http://lists.maptools.org/mailman/listinfo/proj