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7

I bet it may be the slight discrepancy between Esri's WKT definition of 26915 and the OGC WKT version. I think the only real difference is in the name (NAD83 / UTM zone 15N vs NAD_1983_UTM_Zone_15N). You could try making a copy of the shapefile, then replace the PRJ file text with the Esri version linked above.


6

One could use either kind of latitude to locate points on the WGS 84 ellipsoid (used by the NED) or any other ellipsoid, but "everybody knows" that the values will always be given as geodetic latitudes. However, it is surprisingly hard to find an authoritative statement to that effect! Before we go on, it helps to understand that although a datum like the ...


4

The question asks for a rigid motion of the object on an idealization of the earth's surface. For ellipsoids the only continuous families of rigid motions possible are rotations around the earth's axis. But for a spheroidal model there is a three-dimensional family of rigid motions and they can move an object from any location to any other (for two ...


4

Usually the Project Geoprocessing Tool is all you'd need. If you don't want a permanently saved projected dataset you could write to in_memory. In Python, if you set the output featureset to arcpy.Geometry() you can use result.getOutput(0) to get a simple projected Geometry object back.


4

The projection part of the .prj file declares units as meters, so that is what you get. If your data is in degrees, you have to use a .prj file for EPSG:4326: GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]] without any projection information. Looking at the ...


3

Yes, you are right. Finnish nautical maps printed 2002 or before are all based on KKJ coordinated system. KKJ coordinates may differ from GPS-coordinates (WGS84) as much as 200 meters. Starting from 2003 have all new nautical charts been published in EUREF-FIN (appr. WGS 84). These new nautical charts apply international INT chart symbols. Because shallow ...


3

The map object will take on the projection of the first layer you add to it, in the case of your code, the streets basemap is 102100 (web mercator). You have two options to solve this: Use your own basemap service that is in your 102726 projection so that the points from the web service show up in the correct place. Stick with arcgis online basemaps, ...


3

These coordinates are expressed in Military Grid Reference System (MGRS). Thanks Andre for the hint!


3

First, use Define Projection (from the Data Management / Projections and Transformations toolbox). The metadata specifies NAD 83 in decimal degrees, so, GCS_North_American_1983. This gives the shapefile some spatial reference data. After that, you can use Project to turn it into whatever projected coordinate system you want.


2

Those are not not latitude and longitudes. It's (likely) going to be some Projected Coordinate System. The easiest way to figure out which would be to look in the metadata (if it came with any) or contact the agency. They'll know what coordinate system it is. Edit: If for whatever reason you can't get this information from them, I'd start your search ...


2

Finding the "right" projection is a rather time-consuming process. The best way would be to ask the map creator (if he still lives), but I guess this is not the answer you want. So take a look at available map projections, e.g. at http://www.radicalcartography.net/index.html?projectionref, and compare the shape of the degree grid with your example. At ...


2

The coordinates are rather high, so I made a first guess at ft-US units. EPSG:32165 NAD83 / BLM 15N (ftUS) does a good job:


2

Yes it is just the same. Web Mercator goes by 3 different srids (900913 and 3857 being two of them). I'm puzzled you don't have it. 3857 as I recall has been packaged with PostGIS for quite some time. Which PostGIS version are you running? SELECT postgis_full_version();


2

The problem is almost certainly with the "Sphere_Mercator" data. This projected coordinate reference system (CRS) is using a sphere-based geographic CRS. ArcGIS doesn't have any predefined geographic/datum transformations that convert to or from a sphere. The data may have been built on the sphere, or it might have been built on WGS 1984 and then projected ...


2

You might have used Set CRS for layer. This does not reproject any coordinates. Change it back to the original value, and use Save As ... using a different file name and EPSG:4326 as CRS.


1

Use crs function. If r is your raster: crs(r) <- "+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0" Of course, you need to be sure it is the correct projection for your raster.


1

The best tool for coordinate conversion is GDAL's cs2cs. The Lo 22/19 coordinate system is defined by EPSG code 29379, so the command line should be: cs2cs +init=epsg:29379 +to +init=epsg:4326 namibia_in.txt >>namibia_out.txt with this input file namibia_in.txt: 55435.89 -498157.28 Note that your coordinates are named Y;X but have to be ...


1

The Define Projection tool only changes the associated projection, it does not modify the geometry of the feature or shapefile. (Useful if you get data with no associated projection. Not useful if you're trying to transform to a different coordinate system.) Since you ran this before running Project (which mathematically transforms the data into a different ...


1

Another way to determine what coordinate system it is in (if you have some reasonable guesses) would be to load some existing data with the projection defined and then load the data with the coordinates and change the coordinate system of the data frame (right click the "Layers" data frame) to what you think it might be. Reasonable guesses would be the ...


1

As you mention ArcGIS: You could create a fishnet (Note: the link is for ArcGIS 10.0) for your surface und use the resulting polygons to calculate the number of points inside them. Make sure to choose the right projection, as Andre Joost already pointed out. It sounds like you would need to choose an equal area projection.


1

The answer is given in the metadata. Geographic coordinate system Horizontal datum of NAD83, except for AK which is NAD27 Both versions of NAD (North American Datum) are geodetic systems.


1

I had the same issue using eVis. I first thought it was due to using the Dutch coordinate system (EPSG 28992). After selecting a feature with the Event ID-tool the map centered on 0,0, which in this case is somewhere near Paris. The problem was that I was using a Multipoint layer from my PostGIS database. After converting to Point geometries (single-part ...



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