A library for performing conversions between cartographic projections.
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1answer
51 views
Lambert projection with one or two standard parallels and proj4
I'm sure there is a gap in my understanding, but I haven't been able to identify where it is, nor how to fill it. My issue is this:
I'm transforming lon lat coordinates into a lambert conformal ...
3
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0answers
50 views
How can I specify a spatial reference system which has a north pole different than the standard north pole?
I have a geographic spatial reference system (i.e., latitude and longitude) which has a north pole that is not the usual north pole: it's the magnetic north pole at approximately 70.30 degrees north, ...
3
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0answers
242 views
How to define Winkel Tripel in proj 4.8.0?
I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as
+proj=wintri
But that definition string does not work. Is this a bug in my proj version, ...
2
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0answers
57 views
Proj4 inconsistent longitude after projection
All coordinates expressed in this question are (longitude, latitude), the default for proj4. London is at (-0.1460838, 51.5170986), and San Francisco is at (-122.419302, 37.775549). According to the ...
2
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0answers
253 views
Projecting point in Leaflet from EPSG 900913 (same as 3857) to EPSG 2232 with proj4js returning unexpected results
I have a leaflet map from which I want to be able to query an api that accepts x y values in EPSG 2232 as inputs. Leaflet doesn't handle point transformations like Open Layers does so I am trying to ...
2
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0answers
63 views
Proj4s.js Library Transformation Accuracy Documentation
I am using proj4s.js for transforming between coordinate systems for a GIS web application. Is there any documentation out there on transformations accuracy provided by the library?
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43 views
How can I fix badly specified geographic coordinate system with units in arc-seconds?
Check out this depth-to-rock soil data. It is linked from here. The spatial reference system is a latlon, but the units are arcseconds. I could not reason out how to override the SRS even after ...
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0answers
103 views
proj4's omerc projection (cs2cs) broken?
When I project longitude -60, latitude 0 to mercator, I get the
expected answer:
> echo "-60 0" | cs2cs +proj=lonlat +to +proj=merc
-6679169.45 0.00 0.00
However, when I project it to ...
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0answers
136 views
On the usage of Proj4Js->tmerc.js
I am using "proj4js & open layers" for my mapping.
I got projection & datum (which is based on "Transverse Mercator") of a local plane and
this plane is part of a grid which returns ...
1
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0answers
237 views
Conversion From Transverse Mercator To Longitude & Lattitude
I have to transform (7-parameters datum transformation) coordinates from northings & eastings to lattitude & longitude.
Following are details of source coordinate system(i.e. northings & ...
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0answers
207 views
How do I use Proj4js or other technique to make custom map projections with google.maps.Projection?
I'm using Google's Projection class to try to convert my map projection from the default spherical mercator to something like Lambert Conformal Conic. I was previously adapting the code from this ...
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0answers
115 views
Proj4js can't handle 90/180degree transformations from 4326
So if you try to do a transform like this
Proj4js.transform( new Proj4js.Proj( 'EPSG:4326' ),
new Proj4js.Proj( 'EPSG:3857' ),
new Proj4js.Point( -180, -90 ) ...
0
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0answers
22 views
How to set GDAL/cs2cs/proj to use NTv2 grid shift file when using EPSG codes?
I am using the GDAL API for Python for a script that takes only EPSG codes for inputs to specify source and target coordinate systems.
While the cs2cs command seems to handle quite well ...
0
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0answers
56 views
converting instructions to proj4 string for WRF-NMM E-grid
I'm looking for proj4 string for the WRF-NMM weather model projection.
This gris is called Arakama rotated E-Grid.
I spent many time looking on the internet. Here's the only practical thing I found.
...
0
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0answers
64 views
How do I determine programmatically what values to add to the proj4js constructor for a CRS or SRS such that I can iteratively render proper overlays
I think this is primarily a GIS based question as far as for example:
var crs = L.CRS.proj4js('EPSG:2154',
'+proj=lcc +lat_1=49 +lat_2=44 +lat_0=46.5 +lon_0=3 +x_0=700000 ...
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0answers
70 views
Proj4js accuracy compared to Proj4
Is there any lost of accuracy in reprojecting using Proj4js in the browser (compared to using server side Proj4 in Mapserver ) ?
