[PROJ] Problem converting to State Plane Coordinates

[Kristian Evers]

Wayne,

I am not that familiar with the state plane coordinate reference systems but I do know my way around PROJ.
One obvious mistake you are making is the “+nad83:4302”. That is not a valid parameter (proj ignore
parameters it doesn’t recognize). What you are looking for is “+init=nad83:4302”:

$ echo -111.4342412778 40.6680408972 | proj +init=nad83:4302
505560.31       2259209.08

The use of +init-based CRS-descriptions is deprecated though. In modern PROJ this would done with cs2cs
using CRS definitions from the EPSG registry (or the like). I only looked briefly for the correct EPSG-code to
use but couldn’t find one that matches. Someone more familiar with the state plane system can probably
do that easily.

projinfo will tell you have to set up the same transformation using the fully expanded projstring:

$ projinfo +init=nad83:4302
PROJ string:
+proj=lcc +datum=NAD83 +lon_0=-111d30 +lat_1=40d39 +lat_2=39d1 +lat_0=38d20 +x_0=500000 +y_0=2000000 +no_defs

WKT2:2019 string:
CONVERSION["PROJ-based coordinate operation",
    METHOD["PROJ-based operation method: proj=lcc datum=NAD83 lon_0=-111d30 lat_1=40d39 lat_2=39d1 lat_0=38d20 x_0=500000 y_0=2000000 no_defs"]]

In this case it is simply a projection, so you don’t need a pipeline to express this transformation.

/Kristian


From: PROJ <proj-bounces at lists.osgeo.org> On Behalf Of wayne at truwayllc.com
Sent: 12. august 2020 01:44
To: proj at lists.osgeo.org
Subject: [PROJ] Problem converting to State Plane Coordinates

Hello,

I just compiled proj 7.1.0 on my machine and the examples I’ve tried from the Proj website seem to work. I’m trying to convert from Lat/Long coordinates to State Plane zone 4302 (Central Utah). After a bit of searching I found what appears to be the correct syntax to enter the state plane zone "+nad83:4302”. I tried starting with a simplified set of arguments as follows...


$ echo -111.4342412778 40.6680408972 | proj +proj=utm +nad83:4302 +ellps=WGS84
-5286420.10         12245588.21


The expected result (from a tie sheet) is 505560.312 2259209.082


If I Try the same syntax to translate to UTM zone 12 I get a more reasonable result


$ echo -111.4342412778 40.6680408972 | proj +proj=utm +zone=12 +ellps=WGS84
463296.98             4501998.16


What am I doing wrong here?


I would be particularly interested in seeing how to do this with the more modern PROJ pipeline syntax.




Thanks,


Wayne Anderson
wayne at truwayllc.com<mailto:wayne at truwayllc.com>
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