<div dir="ltr"><div>Thank you very much.</div><div>The relief was made with a GNSS receiver (not from me). The people that made it are working for a society that handle municipal waste water and sewers. They use the GNSS as a "tape meter" (with full respect for the employees that must follow the orders from the boss even if they are not qualified).</div><div><br></div><div>I will try to make the same thing with my GNSS to see what QGIS will say to me. I would like to understand. I'll let you know.<br></div><div><br></div><div>Thank you again, <br></div><div>Manolo<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Jun 29, 2023 at 3:35 PM Greg Troxel <<a href="mailto:gdt@lexort.com">gdt@lexort.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Manolo Terranova <<a href="mailto:manoloterranova@gmail.com" target="_blank">manoloterranova@gmail.com</a>> writes:<br>
<br>
> EPSG 32632<br>
<br>
The zip had a shapefile tagged as 32632, with (per ogrinfo):<br>
<br>
Name: String (16.0)<br>
Code: String (60.0)<br>
Northing: Real (18.5)<br>
Easting: Real (18.5)<br>
Elevation: Real (18.5)<br>
OGRFeature(Ponti):0<br>
Name (String) = cs004<br>
Code (String) = pn<br>
Northing (Real) = 5030233.30810<br>
Easting (Real) = 631584.78631<br>
Elevation (Real) = 103.18448<br>
POINT ZM (631584.786313961 5030233.30810281 147.350793083198 1371918614)<br>
<br>
OGRFeature(Ponti):1<br>
Name (String) = cs005<br>
Code (String) = pn<br>
Northing (Real) = 5030233.28520<br>
Easting (Real) = 631584.74959<br>
Elevation (Real) = 103.17660<br>
POINT ZM (631584.749590836 5030233.28520391 147.342911031097 1371918631)<br>
<br>
OGRFeature(Ponti):2<br>
Name (String) = cs006<br>
Code (String) = pn<br>
Northing (Real) = 5030235.54719<br>
Easting (Real) = 631549.52750<br>
Elevation (Real) = 103.27301<br>
POINT ZM (631549.527499332 5030235.54718945 147.438223647885 1371918715)<br>
<br>
The first two points are perhaps the same place, and the third is ~35m<br>
away. The M value is unlabeled, but obviously timeval, 22 June 2013 1630 UTC<br>
ish.<br>
<br>
That is a 2D CRS: WGS 84 / UTM zone 33N. It has no altitude. So having<br>
a Z value does not make sense, but that may be because "POINT M" is not a<br>
thing, at least in Postgis:<br>
<a href="https://postgis.net/docs/ST_MakePoint.html" rel="noreferrer" target="_blank">https://postgis.net/docs/ST_MakePoint.html</a><br>
<br>
So:<br>
<br>
How did you obtain this data?<br>
<br>
Was it autonomous GPS? SBAS differential? RTK? PPP?<br>
<br>
What is the basis of your belief that the data is in 32632?<br>
<br>
[ Standard rant: It is just about inconceivable that you could have<br>
made measurements in the WGS84 ensemble, but perhaps you did RTK and<br>
that reference station only has ensemble coordinates :-) ]<br>
<br>
Where did the Z values come from?<br>
<br>
Why did you store the data in a 2D CRS if it is 3D data? Or if it is<br>
not 3D data, why isn't the Z field consistently 0 or some other undef<br>
codepoint?<br>
<br>
Where did the easting/northing/elevation values come from? The<br>
easting/northing look copied from the POINT values.<br>
<br>
What do you think the altitude of the points ought to be, in the datum<br>
used as HAE, as WGS84 Orthometric Height, or some other orthometric<br>
height datum?<br>
<br>
Overall, the basic issue is your data, not anything about qgis. You<br>
need to understand that measurement pathway and be able to answer the<br>
"why/how" and "I'm skeptical; show me the evidence" questions. If<br>
someone gave you the data file without explaining that, ask them the<br>
above questions. Feel free to tell them the Internet said to be<br>
difficult!<br>
<br>
<br>
<br>
</blockquote></div>