[GRASS5] Use of LINZ grid file

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   entire email cc Paul Kelly, others upon request;
   cc PROJ.4 list if it is of use to anyone there]

Here is some correspondence between me & Land Information New Zealand.

micro-executive summary:
.. we can distribute the New Zealand NTv2 grid file with GRASS if we like ..

I did try using the .gsb file with the 5.0 CVS snapshot of GRASS as per Paul's instructions, but couldn't get it to work properly. But I can't get cs2cs to work with it now either, so I'll have to sort that out first. (file not found)
I did have it working with cs2cs a couple of weeks back though..?

see:
http://www.linz.govt.nz/rcs/linz/pub/web/root/core/SurveySystem/GeodeticInfo/software/index.jsp
- ASCII version of the grid available for individual download
- Binary NTv2 .gsb file is in the GD2000it distribution
- NZGD2000 is WGS84 +/- < 0.10m

regards,
Hamish

=====================================================================
Begin forwarded message:

Date: Mon, 16 Jun 2003 13:28:41 +1200
Subject: Use of LINZ grid file

Hi Hamish,

As you have stated the LINZ web site does not explicitly state the
limitations on usage of the NTv2 distortion model between NZGD49 and
NZGD2000. However the implied limitations that apply to the C code are
also applicable to the grid file.

Therefore you can use the grid file for whatever purpose you like,
however the following (as you have quoted) applies:
* This software may be freely used and modified. It is provided as is,
* where is, with no guarantees as to its correct functioning. Land
* Information New Zealand accepts no liability for any consequences
* of the use of this software.

In summary, you are free to use the grid file in your software, however
LINZ accepts no responsibility or liablility for any consequences of its
usage.
I hope this helps.

Matt Amos

Matt Amos
Geodetic Specialist
Office of the Surveyor-General

Toitu te whenua
Land Information New Zealand

Website: http://www.linz.govt.nz

[...]

Hello -

I am collaborating with the developers of the Open-Source (free) GRASS
GIS software project[1]. Recent updates to the GIS include support for
datum transformations via the PROJ.4 library[2], which among other
things can be used to convert from WGS84 to NZGD49 and NZ Map Grid
within the GIS.

Browsing LINZ site, I found some transform data available for free
download[3], included both with the GD2000it software package (in
binary form) and on its own in ASCII format within file
"nzgd2kgrid9911.zip".

Specifically, those downloads provide a "distortion grid in NTv2
format".

As the latest versions of PROJ.4 (and thus GRASS GIS) now support NTv2
transformations, making NZMG now quite simple and accurate to use
along side lat-lon projects, we would like to redistribute a binary
version of the distortion grid standard with the GIS suite.

It is unclear to me from those software downloads what the licensing
disposition of the grid files are though.

The "source code in the C programming language that implements the
conversion between NZGD2000 and NZGD1949 using the NTv2 ASCII
distortion grid file" provided at the LINZ website states the
following:

* This software may be freely used and modified. It is provided as is,
* where is, with no guarantees as to its correct functioning. Land
* Information New Zealand accepts no liability for any consequences
* of the use of this software.
*
* Copyright: Land Information New Zealand 2001
* Author: Chris Crook

However, the required ASCII grid (a separate download) carries no such
notice. All "for more information" web links to LINZ within the
attached Readme file fail.

The GD2000it software license agreement[4] states in section 3.2
"Subject to clause 3.3 the Licensee shall not copy, alter, modify or
reproduce the Data without the Suppliers prior written consent."
Section 1 defines Data as "the transformation grid file and source
code".

Note that while the .gsb binary grid file is distributed with the
software, it must be loaded (with the equivalent of File->Load) the
first time the program is run, and thus the grid file may be free (to
LINZ) from the license obligations to Univeristy of Melbourne that the
the rest of the GD2000it software may be subject to.

Note also that if it is ok to use the the ASCII version of the grid
file but not the binary copy distributed with the GD2000it software,
the ASCII version may be easily converted by us into a binary form we
could use.

Clarification and/or written consent to redistribute would be greatly
appreciated, as having full, built-in, highly accurate support for NZ
datums and projections in a GIS suite that is freely available for
unlimited student and home use, as well as to those without the
US$20,000 in their budget for a comparable proprietary system, would
be a real boon to many Kiwis.

thanks for your help,
Hamish

[1] http://grass.itc.it
[2] http://www.remotesensing.org/proj
[3]http://www.linz.govt.nz/rcs/linz/pub/web/root/core/SurveySystem/Ge
odeticInfo/software/index.jsp
[4] Help->Contents->Technical Information->GD2000it Licence Agreement

Hello Hamish

On Mon, 23 Jun 2003, H Bowman wrote:

micro-executive summary:
.. we can distribute the New Zealand NTv2 grid file with GRASS if we like ..

Looks good and it seems to work so I have added it to the GRASS CVS.

I did try using the .gsb file with the 5.0 CVS snapshot of GRASS as per
Paul's instructions, but couldn't get it to work properly. But I can't
get cs2cs to work with it now either, so I'll have to sort that out
first. (file not found)
I did have it working with cs2cs a couple of weeks back though..?

cs2cs doesn't look in the current directory by default; you need to use
+nadgrids=./nzgd2kgrid0005.gsb for example, but I think you knew that.

If you run g.setproj in GRASS and select the nzgd49 datum, it should now
offer you the choice of using the grid for your datum transformation
parameters. You will need to have the latest PROJ.4.4.7 installed and have
compiled GRASS using the --with-proj option to the configure script. (The
version of PROJ that comes with GRASS won't work with NTv2 files.)

Also (this may be of interest to PROJ people as well), I didn't get any
feedback on my NTv2 file for France yet. Is it useful to anybody and / or
does it work?
It is at
http://www.stjohnspoint.co.uk/gis/france.htm

Paul Kelly

On Mon, Jun 23, 2003 at 06:52:12PM +1200, H Bowman wrote:

Here is some correspondence between me & Land Information New Zealand.

First: Thanks for the effort, these things are important.

micro-executive summary:
.. we can distribute the New Zealand NTv2 grid file with GRASS if we like ..

Does the data come with all the the necessary freedoms
for everybody to use, modify, adapt and publish it?

We might need a public or written statement.
The general statement below for the software does not
explicitely allow redistribution. It would be better if they
were using a known Free Software license (like X11 license in this case).

The email about the license could be interpreted as
that you (or we), but not everybody else gets that permission,
it would be better of they stated the conditions more clearly
in the distribution archive or on the website.

  Bernhard

see:
http://www.linz.govt.nz/rcs/linz/pub/web/root/core/SurveySystem/GeodeticInfo/software/index.jsp
- ASCII version of the grid available for individual download
- Binary NTv2 .gsb file is in the GD2000it distribution
- NZGD2000 is WGS84 +/- < 0.10m

=====================================================================
Begin forwarded message:

Date: Mon, 16 Jun 2003 13:28:41 +1200
Subject: Use of LINZ grid file

As you have stated the LINZ web site does not explicitly state the
limitations on usage of the NTv2 distortion model between NZGD49 and
NZGD2000. However the implied limitations that apply to the C code are
also applicable to the grid file.

Therefore you can use the grid file for whatever purpose you like,
however the following (as you have quoted) applies:
* This software may be freely used and modified. It is provided as is,
* where is, with no guarantees as to its correct functioning. Land
* Information New Zealand accepts no liability for any consequences
* of the use of this software.

In summary, you are free to use the grid file in your software, however
LINZ accepts no responsibility or liablility for any consequences of its
usage.

Matt Amos
Geodetic Specialist
Office of the Surveyor-General

Toitu te whenua
Land Information New Zealand

Website: http://www.linz.govt.nz

> I am collaborating with the developers of the Open-Source (free) GRASS
> GIS software project[1]. Recent updates to the GIS include support for
> datum transformations via the PROJ.4 library[2], which among other
> things can be used to convert from WGS84 to NZGD49 and NZ Map Grid
> within the GIS.
>
> Browsing LINZ site, I found some transform data available for free
> download[3], included both with the GD2000it software package (in
> binary form) and on its own in ASCII format within file
> "nzgd2kgrid9911.zip".
>
> Specifically, those downloads provide a "distortion grid in NTv2
> format".
>
>
> As the latest versions of PROJ.4 (and thus GRASS GIS) now support NTv2
> transformations, making NZMG now quite simple and accurate to use
> along side lat-lon projects, we would like to redistribute a binary
> version of the distortion grid standard with the GIS suite.
>
> It is unclear to me from those software downloads what the licensing
> disposition of the grid files are though.
>
> The "source code in the C programming language that implements the
> conversion between NZGD2000 and NZGD1949 using the NTv2 ASCII
> distortion grid file" provided at the LINZ website states the
> following:
>
> * This software may be freely used and modified. It is provided as is,
> * where is, with no guarantees as to its correct functioning. Land
> * Information New Zealand accepts no liability for any consequences
> * of the use of this software.
> *
> * Copyright: Land Information New Zealand 2001
> * Author: Chris Crook
>
> However, the required ASCII grid (a separate download) carries no such
> notice. All "for more information" web links to LINZ within the
> attached Readme file fail.
>
>
> The GD2000it software license agreement[4] states in section 3.2
> "Subject to clause 3.3 the Licensee shall not copy, alter, modify or
> reproduce the Data without the Suppliers prior written consent."
> Section 1 defines Data as "the transformation grid file and source
> code".
>
> Note that while the .gsb binary grid file is distributed with the
> software, it must be loaded (with the equivalent of File->Load) the
> first time the program is run, and thus the grid file may be free (to
> LINZ) from the license obligations to Univeristy of Melbourne that the
> the rest of the GD2000it software may be subject to.
>
> Note also that if it is ok to use the the ASCII version of the grid
> file but not the binary copy distributed with the GD2000it software,
> the ASCII version may be easily converted by us into a binary form we
> could use.
>
>
> Clarification and/or written consent to redistribute would be greatly
> appreciated, as having full, built-in, highly accurate support for NZ
> datums and projections in a GIS suite that is freely available for
> unlimited student and home use, as well as to those without the
> US$20,000 in their budget for a comparable proprietary system, would
> be a real boon to many Kiwis.
>
>
> thanks for your help,
> Hamish
>
>
> [1] http://grass.itc.it
> [2] http://www.remotesensing.org/proj
> [3]http://www.linz.govt.nz/rcs/linz/pub/web/root/core/SurveySystem/Ge
> odeticInfo/software/index.jsp
> [4] Help->Contents->Technical Information->GD2000it Licence Agreement

On Mon, 23 Jun 2003, Bernhard Reiter wrote:

Does the data come with all the the necessary freedoms
for everybody to use, modify, adapt and publish it?

We might need a public or written statement.
The general statement below for the software does not
explicitely allow redistribution. It would be better if they
were using a known Free Software license (like X11 license in this case).

The email about the license could be interpreted as
that you (or we), but not everybody else gets that permission,
it would be better of they stated the conditions more clearly
in the distribution archive or on the website.

'It would be better........' but it's adequate the way it is, right?
Should we have a special text file in the directory where the grid shift
files are stored, explaining the licensing conditions for each one?

The USA and Canada files were added last year I think and probably they
also are provided under some similar free distribution terms.

Maybe someone can undertake to check this up and collect all the terms /
conditions into one file.

Paul

On Mon, Jun 23, 2003 at 04:55:12PM +0100, Paul Kelly wrote:

On Mon, 23 Jun 2003, Bernhard Reiter wrote:

> Does the data come with all the the necessary freedoms
> for everybody to use, modify, adapt and publish it?
>
> We might need a public or written statement.
> The general statement below for the software does not
> explicitely allow redistribution. It would be better if they
> were using a known Free Software license (like X11 license in this case).
>
> The email about the license could be interpreted as
> that you (or we), but not everybody else gets that permission,
> it would be better of they stated the conditions more clearly
> in the distribution archive or on the website.

'It would be better........' but it's adequate the way it is, right?

Thinking a few more minutes about it, I believe the email you've got
might be okay and "use freely" can reasonably interpreted as
permission to distribute and publish modifications.

Should we have a special text file in the directory where the grid shift
files are stored, explaining the licensing conditions for each one?

The USA and Canada files were added last year I think and probably they
also are provided under some similar free distribution terms.

Maybe someone can undertake to check this up and collect all the terms /
conditions into one file.

This would be important, yes.

Everybody checking stuff into the CVS (for the official part of the
sources) should be responsible
that the license is compatible with the license of GRASS.
If the license is difference from the GNU GPL, it needs to be
documented properly.