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location Redlands, CA
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visits member for 4 years, 6 months
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I've been working with map projections and datum transformations for years, including in ArcView GIS, ArcInfo 7 and up, MapObjects, and ArcGIS.


1d
comment ESRI/Mapinfo MGA56 prj vs QGIS MGA56 prj
Esri originally wrote out the 2nd number (...3295) then later decided to make it more true to double precision so we now write out (...33). In our testing, we found no differences in results using either number.
1d
answered Latitudes and Longitudes in Atlas
Mar
31
comment UTM ED 50 transformation to WGS84
I just wanted to confirm that you are setting a tfm in ArcMap. Some people don't realize that ArcMap doesn't automatically set a particular geographic/datum transformation.
Mar
30
answered Meter Coordinates to decimal Coordinates
Mar
30
comment UTM ED 50 transformation to WGS84
Are you also setting the same transformation in ArcMap?
Mar
30
comment Wetterzentrale maps georeferencing - coordinate system?
Guess: north pole-centered stereographic with a central meridian/longitude of origin around -20.
Mar
27
reviewed Edit Programmatically grouping multiple layers into separate groups using QGIS?
Mar
27
revised Programmatically grouping multiple layers into separate groups using QGIS?
grammar & spelling
Mar
27
comment Reprojecting from Lambert Conformal Conic into EPSG:3857?
No problem! To convert the lat/lon values to the LCC coordinate system, you have to label them at lat/lon in the cs2cs statement. Right now you're saying they're in 3857 which is a projected coordinate system. It should start with "+proj=latlong +a=6371200 +b=6371200...". with the same sphere radius as the LCC system.
Mar
25
comment Adding VBA code to ArcMap
resources.arcgis.com/en/help/install-guides/arcgis-desktop/10.2/…
Mar
25
comment Reprojecting from Lambert Conformal Conic into EPSG:3857?
Your input values of your first cs2cs statement are lat/lon not EPSG:3857. And they're probably relative to the sphere that you're referencing, not WGS84 (EPSG:4326).
Mar
25
comment Different SRID problem
Now posted on geonet as well.
Mar
25
comment Are there different EPSG codes for 6 digit, 7 digit and 8 digit UTM Zone32 coordinate systems (CRS)?
The N32 is for a ProjCRS that has axis order easting-northing. Its name in EPSG is now: ETRS89 / UTM zone 32N (zE-N) and we're (esri) behind-the-times. Traditionally, Germany has used northing-easting axis ordering, but some authorities have requested easting-northing order.
Mar
25
comment Converting from an x-y coordinate system to latitude/longitude
A better utility from the same group (with more explanation) is at whoi.edu/marine/ndsf/utility/NDSFutility.html
Mar
24
reviewed Reviewed Add point button missing from CartoDB?
Mar
24
comment Add point button missing from CartoDB?
What software, including version, are you using?
Mar
20
comment Erroneous location when converting from a GCS_WGS_1984 to UTM
Are you trying to match these up to a Web Mercator base map? If so, try using 3857 for the output coordinate system.
Mar
20
comment National Bridge Inventory (NBI) data coordinate system
Once you've converted the DMS to decimal degrees, I would use NAD 1983, a geographic coordinate system.
Mar
20
comment National Bridge Inventory (NBI) data coordinate system
There's no hemisphere information. Probably assuming positive west longitudes. Here's a sample in Alaska: 55074800131341800. Thus latitude = 55 07 48 and longitude = 131 34 18. The trailing zeroes could mean it's DDMMSS.ss and DDDMMSS.ss.
Mar
19
comment Re-projecting point data using ArcMap
The tools in ArcGIS for these steps are to use the georeferencing toolbar for the png file (you'll need to have some control points whose CRS and coordinates are known) and the spatial adjustment toolbar for the points. You may find that the latter isn't working that well and then decide to redigitize the points.