<HTML dir=ltr><HEAD><TITLE>Re: [Gvsig_english] BIG problems with reprojecting AGD66 to GDA94</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Hello, Simon:</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>I renamed the gsb file to 'a66_national.gsb' because I don't like white spaces, brackets,etc. I used gvSIG 1.1.2, not gvSIG 1.9. I have now tried 1.9 and I think it does not work, though a similar gsb grid for Spain does work.</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Another option (out of gvSIG) is using the FWTools package ( <A href="http://fwtools.maptools.org">http://fwtools.maptools.org</A> ). It provides a series of text-mode tools to be started from a DOS-style window or terminal if you are using Linux. You can use the grid with it too. This worked for me:</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>EPSG:4202 to EPSG:4283</FONT></DIV>
<DIV dir=ltr><FONT face="Courier New" color=#000000 size=2>ogr2ogr -f "ESRI Shapefile" -s_srs "+proj=longlat +ellps=aust_SA +nadgrids=./a66_national.gsb +wktext" -t_srs EPSG:4283 target_4283.shp source_4202.shp</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>EPSG:4283 to EPSG:4202</FONT></DIV>
<DIV dir=ltr><FONT face="Courier New" color=#000000 size=2>ogr2ogr -f "ESRI Shapefile" -s_srs "+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +nadgrids=./a66_national.gsb +wktext" -t_srs EPSG:4202 target_4202.shp source_4283.shp</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Shapefiles and grid need to be in the same folder. Notice that the two last parameters are <output_file> <input_file></FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=3>Regards,</FONT></DIV>
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<DIV><FONT face="Courier New" size=2><FONT face="Times New Roman" size=3>Juan Lucas Domínguez Rubio<BR></FONT>---</FONT></DIV>
<DIV><FONT face="Courier New" size=2><FONT face="Courier New" size=2><FONT face="Courier New" size=2>Prodevelop SL, Valencia (España)</FONT></DIV>
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<DIV><FONT face="Courier New" size=2>Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR></FONT><A href="http://www.prodevelop.es/"><FONT face="Courier New" size=2>http://www.prodevelop.es</FONT></A><BR><FONT face="Courier New" size=2>---</FONT></DIV></FONT></DIV></FONT></DIV>
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<FONT face=Tahoma size=2><B>De:</B> gvsig_internacional-bounces@listserv.gva.es en nombre de Simon Cropper (Botanicus Australia Pty Ltd)<BR><B>Enviado el:</B> mar 01/12/2009 6:22<BR><B>Para:</B> Users and Developers mailing list<BR><B>Asunto:</B> Re: [Gvsig_english] BIG problems with reprojecting AGD66 to GDA94<BR></FONT><BR></DIV>
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<P><FONT size=2>Hi Juan Lucus,<BR><BR>I followed your instructions in gvSIG Version 1.9 (Build 1253) and it<BR>does not work.<BR><BR>The only difference is that when I select transformation the following<BR>drop down list appears -- notice that "NT v2 grid file" appears rather<BR>than "Grids" as in your video. I only see 'Grids" if I use gvSIG Version<BR>1.1.1 (Build 1022), but even so, if I repeat you tutorial it still does<BR>not work.<BR><BR>Note also that the GRID file is named differently. The link I pointed to<BR>allows me to download "A66 National (13.09.01).gsb". I notice that you<BR>have "A66 National" in your video. Where did you get your Grid File?<BR>None of the links I provided point to a "A66 National" file - maybe it<BR>is in a different format. Also why is my version showing NT v2 format<BR>grid file, and yours is not?<BR><BR>That fact that you can get it to work is encouraging. In the nutshell<BR>the question is why is my setup different than yours.<BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR>Cheers Simon<BR><BR>Simon Cropper<BR>Botanicus Australia Pty Ltd<BR>PO Box 160, Sunshine, Victoria 3020.<BR>P: 9311 5822. M: 041 830 3437.<BR>mailto: scropper@botanicusaustralia.com.au<BR><<A href="mailto:scropper@botanicusaustralia.com.au">mailto:scropper@botanicusaustralia.com.au</A>><BR>web: www.botanicusaustralia.com.au <<A href="http://www.botanicusaustralia.com.au/">http://www.botanicusaustralia.com.au</A>><BR><BR><BR><BR>Juan Lucas Dominguez Rubio wrote:<BR>> Excuse me, Simon. The Australian GSB grid file does work in gvSIG:<BR>> <BR>> <A href="http://www.youtube.com/watch?v=eDfgMFlUnWo">http://www.youtube.com/watch?v=eDfgMFlUnWo</A><BR>> (full screen recommended)<BR>> <BR>> From EPSG:4202 to EPSG:4283: choose the left radio button (Layer SRS -<BR>> EPSG:4202) as seen in the video.<BR>> From EPSG:4283 to EPSG:4202: choose the right radio button (View SRS -<BR>> EPSG:4202).<BR>> <BR>> Regards,<BR>> <BR>> <BR>> Juan Lucas Domínguez Rubio<BR>> ---<BR>> Prodevelop SL, Valencia (España)<BR>> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR>> <A href="http://www.prodevelop.es/">http://www.prodevelop.es</A> <<A href="http://www.prodevelop.es/">http://www.prodevelop.es/</A>><BR>> ---<BR>><BR>> ------------------------------------------------------------------------<BR>> *De:* gvsig_internacional-bounces@listserv.gva.es en nombre de Simon<BR>> Cropper (Botanicus Australia Pty Ltd)<BR>> *Enviado el:* lun 30/11/2009 1:36<BR>> *Para:* Users and Developers mailing list<BR>> *Asunto:* Re: [Gvsig_english] BIG problems with reprojecting AGD66 to<BR>> GDA94<BR>><BR>> Juan Lucas,<BR>><BR>> Thanks for the feedback. So that others are able to follow the thread<BR>> and have the outcome at their disposal I will repeat what has been<BR>> stated so far both in this email and other that you have sent me.<BR>><BR>> *OBSERVATION A*<BR>><BR>> If you are using the reprojection tool and converting between systems in<BR>> the same datum then the tool will work.<BR>><BR>> This means if you are converting between AGD66 GEO <=> AGD66 AMG55 <=><BR>> AGD66 VicGrid there are no problems.<BR>><BR>> This also applies for GDA94 GEO <=> GDA94 MGA55 <=> GDA94 VicGrid.<BR>><BR>> *OBSERVATION B*<BR>><BR>> It is necessary to 'transform' a dataset if you are changing between<BR>> datums. That is, moving between AGD66 to GDA94 or back the other way.<BR>><BR>> The regional transformation parameters for Victoria are published by the<BR>> Intergovernmental Committee of Surveying and Mapping in the GDA94<BR>> Technical manual Version 2.3, Amendment 1<BR>> (<A href="http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf">http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf</A>).<BR>><BR>> The parameters *DO NOT WORK IF PLUGGED INTO THE REPROJECTION TOOL AS IS,<BR>> YOU NEED TO CHANGE THE SIGN (+/-) OF VARIOUS VALUES DEPENDING ON YOUR<BR>> DESIRED OUTCOME !* This is done by manually transforming the vector<BR>> files by typing in the following values under the various situation<BR>> specified.<BR>><BR>> The following values can be used to _correctly reproject one file to<BR>> another file_. Note you need to ensure the signs before the various<BR>> values are correct.<BR>><BR>> _*File2File: AGD66 => GDA94*_<BR>> Dx = 119.353<BR>> Dy = 48.301<BR>> Dz = -139.484<BR>> Rx = -0.415<BR>> Ry = -0.26<BR>> Rx = -0.437<BR>> Sc = 0.613<BR>><BR>> _*File2File: GDA94 => AGD66*_<BR>> Dx = -119.353<BR>> Dy = -48.301<BR>> Dz = 139.484<BR>> Rx = 0.415<BR>> Ry = 0.26<BR>> Rx = 0.437<BR>> Sc = -0.613<BR>><BR>><BR>> If you are _reprojecting of the fly_. The values are reversed.<BR>><BR>> *_View Projection=AGD66; File Projection=GDA94_*<BR>> Dx = 119.353<BR>> Dy = 48.301<BR>> Dz = -139.484<BR>> Rx = -0.415<BR>> Ry = -0.26<BR>> Rx = -0.437<BR>> Sc = 0.613<BR>><BR>> _*View Projection=GDA94; File Projection=AGD66*_<BR>> Dx = -119.353<BR>> Dy = -48.301<BR>> Dz = 139.484<BR>> Rx = 0.415<BR>> Ry = 0.26<BR>> Rx = 0.437<BR>> Sc = -0.613<BR>><BR>><BR>> What is frustrating is that these values need to be entered every time<BR>> you make a change. Very laborious and also prone to typographical errors.<BR>><BR>> The GDA Technical Manual indicates that this 'rough' transformation has<BR>> an accuracy of about 1 metre. The observations made by Juan Lucas<BR>> supports this claim. I also found that in points I checked the values<BR>> were <1m from the reference points created using the transformation grid<BR>> and that the transformation work for latitude-longitude as well as<BR>> northing-easting.<BR>><BR>> *OBSERVATION C*<BR>><BR>> Although a transformation grid is available, apparently in the correct<BR>> format, this grid does not work with gvSIG.<BR>><BR>> *OBSERVATION D*<BR>><BR>> Although I am not happy that the transformation grid does not work as my<BR>> reprojected points are not exactly the same as the reference points, the<BR>> question is whether I am in any better position if I use ArcView (the<BR>> pseudo-reference point at the moment). The answer is NO. I reprojected<BR>> the same source using ArcView and found that points in the two<BR>> reprojected files were <1cm apart. Not exactly the same but close enough<BR>> that the gvSIG measure tool did not register the difference (although it<BR>> did plot them in different locations if you zoomed in enough). I suspect<BR>> that the two points differ because the ArcView procedure uses an earlier<BR>> version of the Regional Transformation Parameters.<BR>><BR>> *MY SUGGESTIONS*<BR>><BR>> *Suggestion 1.* The reprojection tool should produce and error, or at<BR>> least a warning, if the source file and destination files are not in the<BR>> same datum letting the user know that it is necessary to select an<BR>> appropriate transformation. The impression you get when selecting a<BR>> source DATUM-COORDINATE combo and a destination DATUM-COORDINATE combo<BR>> that the system is automatically sorting this issue out.<BR>><BR>> *Suggestion 2.* Someone should look at the transformation grid produced<BR>> by the Intergovernmental Committee of Surveying and Mapping and figure<BR>> out why it does not work. gvSIG can't truly become an international<BR>> package if files apparently in the correct format don't work, and that<BR>> values (in this case rotation values published in the literature) have<BR>> to have their signs reversed in gvSIG to get the transformation to work<BR>> properly.<BR>><BR>> *Suggestion 3.* OK, a work around has been found but it is not simple or<BR>> quick. Manual values need to be entered, but these vary depending on the<BR>> situation (see above), and they need to be entered every time you<BR>> conduct a reprojection. It would be advantageous if manually entered<BR>> data could be saved and subsequently picked from a list. This would<BR>> speed up the process and avoid typographical errors resulting in the<BR>> incorrect reprojection of data.<BR>><BR>> Thanks Juan Lucas for your feedback on this issue.<BR>><BR>> Cheers Simon<BR>><BR>> Simon Cropper<BR>> Botanicus Australia Pty Ltd<BR>> PO Box 160, Sunshine, Victoria 3020.<BR>> P: 9311 5822. M: 041 830 3437.<BR>> mailto: scropper@botanicusaustralia.com.au<BR>> <<A href="mailto:scropper@botanicusaustralia.com.au">mailto:scropper@botanicusaustralia.com.au</A>><BR>> web: www.botanicusaustralia.com.au<BR>> <http://www.botanicusaustralia.com.au <BR>> <<A href="http://www.botanicusaustralia.com.au/">http://www.botanicusaustralia.com.au/</A>>><BR>><BR>><BR>><BR>> Juan Lucas Dominguez Rubio wrote:<BR>> > Hello, Simon.<BR>> ><BR>> > I have done a test with a view in EPSG:4202 and two shapefiles (a<BR>> > target shapefile in EPSG:4202 and a source shapefile in EPSG:4283)<BR>> > extracted from your DBF. After adding the target shapefile (same<BR>> > projection as the view) I have added the source shp trying a variety<BR>> > of transformations. When you add it to the view, gvSIG lets you choose<BR>> > among eleven available "EPSG transformations" between those two EPSG<BR>> > codes. The one that gives me the best result is the first one:<BR>> ><BR>> > Transformation code: 1278<BR>> > Name: AGD66 to GDA94 (1)<BR>> > (we are actually doing the inverse transformation (GDA94 to AGD66) but<BR>> > the algorithm seems to be aware of this and does it well)<BR>> ><BR>> > I have measured the distance between the obtained coordinates<BR>> > (transformed source shp) and the expected coordinates (target<BR>> > shp) for 5 random points and I get these errors:<BR>> ><BR>> > 1.2 m<BR>> > 0.9 m<BR>> > 1.57 m<BR>> > 0.88 m<BR>> > 0.96 m<BR>> ><BR>> > I have also looked into some pdf files and I have found these<BR>> > parameters (AGD66 to GDA94) for Victoria and NSW:<BR>> ><BR>> > <A href="http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf">http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf</A><BR>> ><BR>> > Dx = -119.353<BR>> > Dy = -48.301<BR>> > Dz = 139.484<BR>> > Rx = -0.415<BR>> > Ry = -0.26<BR>> > Rx = -0.437<BR>> > Sc = -0.613<BR>> ><BR>> > Since we are doing the inverse transfomation, we should reverse the<BR>> > sign for each parameter, but I don't get good results.<BR>> ><BR>> > I have also read somewhere that in Australia and the US, the rotation<BR>> > parameters have the inverse meaning than in Europe (big ???), so I<BR>> > tried these parameters (reversing the ones above except for the<BR>> > rotation parameters):<BR>> ><BR>> > Dx = 119.353<BR>> > Dy = 48.301<BR>> > Dz = -139.484<BR>> > Rx = -0.415<BR>> > Ry = -0.26<BR>> > Rx = -0.437<BR>> > Sc = 0.613<BR>> ><BR>> > And indeed, I get significantly smaller errors for those 5 points:<BR>> ><BR>> > 0.7 m<BR>> > 0.15 m<BR>> > 0.75 m<BR>> > 0.8 m<BR>> > 0.25 m<BR>> ><BR>> > Those 7 parameters can be entered with the "manual transformation"<BR>> > option. I didn't get the grid to work either, sorry, although the<BR>> > format seems to be one supported by gvSIG. And I have not done any<BR>> > tests with non-geographical SRS.<BR>> ><BR>> > Regards,<BR>> ><BR>> > Juan Lucas Domínguez Rubio<BR>> > ---<BR>> > Prodevelop SL, Valencia (España)<BR>> > Tlf.: 96.351.06.12 -- Fax: 96.351.09.68<BR>> > <A href="http://www.prodevelop.es/">http://www.prodevelop.es</A> <<A href="http://www.prodevelop.es/">http://www.prodevelop.es/</A>><BR>> <<A href="http://www.prodevelop.es/">http://www.prodevelop.es/</A>><BR>> > ---<BR>> ><BR>> > ------------------------------------------------------------------------<BR>> > *De:* gvsig_internacional-bounces@listserv.gva.es en nombre de Simon<BR>> > Cropper (Botanicus Australia Pty Ltd)<BR>> > *Enviado el:* sáb 28/11/2009 7:36<BR>> > *Para:* Users and Developers mailing list<BR>> > *Asunto:* [Gvsig_english] BIG problems with reprojecting AGD66 to GDA94<BR>> ><BR>> > Hi Guys,<BR>> ><BR>> > I am having problems getting the reproject tool to work as expected with<BR>> > Australian Projections/Datums.<BR>> ><BR>> > If I create a shapefile in AGD66 then reproject the file to GDA94 using<BR>> > the reproject tool, the points are moved but only ~20m rather than 204<BR>> > metres northeast of the original position. If I use the resulting GDA94<BR>> > file in the AGD66 View and tell the program, it reprojects on the fly<BR>> > and the points overlap.<BR>> ><BR>> > This shows (a) that the reproject on the fly facility works, and (b) I<BR>> > appear to have chosen the wrong projection.<BR>> ><BR>> > The problem is I have tried reprojecting northing-eastings,<BR>> > latitude-longitude, in EPSG and ESRI format but can't get the correct<BR>> > reprojection. I have been using EPSG:4202 for AGD66 geographicals,<BR>> > EPSG:4283 for GDA94 geographicals, EPSG:20255 for AGD/ AMG zone 55 and<BR>> > EPSG:28355 for GDA94/MGA zone 55. I have also tried ESRI: 28355 and<BR>> > ESRI:20255 with no luck.<BR>> ><BR>> > I have even downloaded the transformation grid but not been able to get<BR>> > this to work either.<BR>> ><BR>> > Can anyone help?<BR>> ><BR>> > Attached is a list of points in a table that are released by the local<BR>> > government apparently created by FME. This has the comparable<BR>> > coordinates in 4 commonly used projections for 160 distinct points<BR>> > across Victoria.<BR>> ><BR>> > Can anyone get the correct setting and procedure to get these points to<BR>> > superimpose when reprojecting on the fly and for the reproject facility<BR>> > to work correctly?<BR>> ><BR>> > I have also included some useful links to help the more industrious and<BR>> > knowledgeable to figure out what is wrong.<BR>> ><BR>> ><BR>> <A href="http://www.land.vic.gov.au/Land/lcnlc2.nsf/LinkView/9B33746B3D77040F4A256A250008E70A5B923E73477D6D65CA256E5F0013D73B">http://www.land.vic.gov.au/Land/lcnlc2.nsf/LinkView/9B33746B3D77040F4A256A250008E70A5B923E73477D6D65CA256E5F0013D73B</A><BR>> ><BR>> > <A href="http://www.icsm.gov.au/icsm/gda/gdatm/">http://www.icsm.gov.au/icsm/gda/gdatm/</A><BR>> ><BR>> > <A href="http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf">http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf</A><BR>> ><BR>> > Any help would be appreciated as I am trying to tick this off my list of<BR>> > things gvSIG can do, and was surprised to see when resulting reprojected<BR>> > files were compared to external reference documents they did not align.<BR>> ><BR>> > Any help would be greatly appreciated.<BR>> > --<BR>> ><BR>> > Cheers Simon<BR>> ><BR>> > Simon Cropper<BR>> > Botanicus Australia Pty Ltd<BR>> > PO Box 160, Sunshine, Victoria 3020.<BR>> > P: 9311 5822. M: 041 830 3437.<BR>> > mailto: scropper@botanicusaustralia.com.au<BR>> > <<A href="mailto:scropper@botanicusaustralia.com.au">mailto:scropper@botanicusaustralia.com.au</A>><BR>> > web: www.botanicusaustralia.com.au<BR>> > <http://www.botanicusaustralia.com.au<BR>> > <<A href="http://www.botanicusaustralia.com.au/">http://www.botanicusaustralia.com.au/</A>>><BR>> ><BR>> > ------------------------------------------------------------------------<BR>> ><BR>> > _______________________________________________<BR>> > Gvsig_internacional mailing list<BR>> > Gvsig_internacional@listserv.gva.es<BR>> > <A href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A><BR>> > <BR>> _______________________________________________<BR>> Gvsig_internacional mailing list<BR>> Gvsig_internacional@listserv.gva.es<BR>> <A href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A><BR>><BR>> ------------------------------------------------------------------------<BR>><BR>> _______________________________________________<BR>> Gvsig_internacional mailing list<BR>> Gvsig_internacional@listserv.gva.es<BR>> <A href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A><BR>> <BR>_______________________________________________<BR>Gvsig_internacional mailing list<BR>Gvsig_internacional@listserv.gva.es<BR><A href="http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional">http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional</A><BR></FONT></P></DIV></BODY></HTML>