[Qgis-user] CRS / reprojection problems

[Matt Boyd]

Kosza replied to me and suggested I try epsg 4283 instead of epsg 4938

Is it usual to have 2 CRS with the same name, one of which appears to be
projected and the other not, I don't think I've seen this before. There
still seems to be something odd about 4938, but I don't see any reason to
use it so it shouldn't bother me.

Here's where I can learn something. Does anyone know what the deal with
this is? I can see a need for a different projections, but is there
supposed to be a better way of naming it that I didn't pick up on, am I
going to need to remember epsg codes form now on?

Thanks
Matt

On Wed, May 22, 2019 at 11:51 PM Nicolas Cadieux <
nicolas.cadieux at archeotec.ca> wrote:

> Hi,
> Right clicking on the layer in the layer panel and changing the projection
> to the correct one should then fix the problem.  Tell me if it’s still a
> problem and I will also look at the data.
> Nicolas
>
> Le 22 mai 2019 à 03:34, <b.j.kobben at utwente.nl> <b.j.kobben at utwente.nl> a
> écrit :
>
> Sorry to have to disagree with you, but there is something wrong with your
> data. If I load the "lineations_GDA94" it claims to be a projected data,
> and the units are clearly meters (numbers like -42854769,3100060 in the
> coordinate readout). But if you check, you'd find that  QGIS thinks the
> units are degrees:
>
>
>
> <image001.png>
>
>
>
> Treating the meter cooridnates as degrees works as long as no reprojection
> is needed, but will mess up things when combining it with other data...
>
>
>
>
>
> --
>
> Barend Köbben
>
>
>
>
>
> On 22/05/2019, 05:54, "Qgis-user on behalf of Matt Boyd" <
> qgis-user-bounces at lists.osgeo.org on behalf of mattslists at gmail.com>
> wrote:
>
>
>
> Hi Nicolas and Alexandre,
>
> I'm pretty sure that I've done as much as I can to make sure I haven't
> screwed up the projections. I used to make those mistakes years ago when I
> was first learning, lately the mistakes I've made are because I haven't
> been paying attention... I'm pretty sure I'm paying attention this time.
>
>
>
> This is a link to some data and a qgis file I'm using as an example
>
>
> https://unimelbcloud-my.sharepoint.com/:f:/g/personal/boydmc_student_unimelb_edu_au/EuUzfUvxA6NGmZOuYo8_fmkB0AvLldzBmXwq68mdwZvmcw?e=Ake4Qi
>
>
>
> lineations_MGA54_projected is the shapefile with the correctly projected
> information layer. - Known good data
>
>
>
> If I change to a geogrpahic / unprojected coordinate system, for example
> GDA94, this layer is not displayed and the canvas is blank.
>
>
>
> If I export the lineations_MGA54_projected data to a new file as
> unprojected GDA94 option, the re-projected data is wrong.
>
>
>
> Thanks for your help
>
>
>
> Matt
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Tue, May 21, 2019 at 11:37 PM Nicolas Cadieux <
> nicolas.cadieux at archeotec.ca> wrote:
>
> Hi,
>
> 99 % of the time, the data is the problem because it’s in the wrong crs.
> Right click on the problem layer in the layer panel and change the layer
> crs to what is should be.  Use a google or other base map from quickmap
> plugin.  That should permit you to find the correct CRS.
>
> Sometimes, crs will have problems reprojecting across some latitudes or
> longitude (like projections make for the poles).  In that case,
> reprojecting the data using the “save as” option will solve the problem.
>
> Nicolas
>
> > Le 20 mai 2019 à 21:53, Matt Boyd <mattslists at gmail.com> a écrit :
> >
> > Hi QGISers,
> > I'm having an issue with reprojecting things in QGIS.
> > Installer OSGEO64W
> > Latest version and LTS both have same issue.
> >
> > Issue:
> > reprojection just isn't working. If I load a data set with decimal
> degrees and another with a projected coordinate system the data (points /
> lines / polygons) will only display if the basemap is in the same
> projection system.
> >
> > This is happening across 2 PCs, (windows10) and the LTS and latest
> versions of QGIS. Has anyone got some troubleshooting tips?
> >
> > Thanks
> > Matt
> > _______________________________________________
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> > Qgis-user at lists.osgeo.org
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>
>
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