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4

Trying to find a solution, I've changed OpenLayers.js file, provided by plugin authors (which had 'Release 2.11' version in his body and was placed at ~/.qgis2/python/plugins/openlayers_plugin/weblayers/html folder in my system) to last 2.13.1 version from official OpenLayers site (pay attention, 2.+ version!). Just download the archive, extract to ...


4

The geographic coordinates systems (also called lat/long) are defined by 3 features : a datum, a prime meridian (most of the time, it is Greenwich) and a unit (most of the time, it is degree). The EPSG code help to unambiguously identify a geographic coordinate sytem (you can find the description on spatial reference.org) GEOGCS["WGS 84", ...


4

Georeferencing is a process where you define which coordinates your image covers. It'll write in the coordinate system of the data frame. Therefore, it does not specify which coordinate system you use, only which coordinates it covers. The tool Define projection (under Data Management --> Projections and transformations) can be used on both vector and ...


4

I'll use spherical coordinates as defined here on Wikipedia which uses phi and theta (which is probably your lambda). Phi is the angle from the north pole. Hence if the WGS84 point is 10.0.0N, phi will be 80 degrees. For a point in the southern hemisphere, say 12.30.00S, phi will be 90 + 12.5 = 102.5 degrees. Theta is just the longitude in degrees, if the ...


4

You could calculate ST_Area on a geography type. Since you have data with WGS84 (SRID=4326), you can add a simple geography cast, e.g. SELECT ST_Area(geom::geography) which will return area in m² on a curved surface (sphereoid by default). This should be pretty close to the true surface area, without requiring any projection. It would be interesting to ...


4

The northern two-thirds of Georgia should be pretty good, because the South Carolina coordinate reference system is Lambert conformal conic-based. Thus, the standard parallels extend through Georgia too. I ran a point at 31N 85W through the National Geodetic Survey's SPC program to see what the distortion would be. Note: South Carolina's zone is 3900. It ...


3

In Settings -> Options -> CRS tab, you can select to Prompt for CRS for new layers. That should avoid the automatic assigning of wrong projections.


3

PRJ files define the projection of the shapefile. To create one define the projection in ArcCatalog either by using the tool Define Projection or right click on the layer and select properties (there's a whole dialog there). It would also be sufficient to copy the prj file from your input and rename it to match the shape file. Considering you're doing this ...


3

I am unclear why you prefer the name to the factory code. You can use the srid and there is no fuss with spaces/underscores. For projected systems: http://resources.arcgis.com/en/help/main/10.2/018z/pdf/projected_coordinate_systems.pdf For geog. Systems: http://resources.arcgis.com/en/help/main/10.2/018z/pdf/geographic_coordinate_systems.pdf If you are ...


3

To determine whether an arcpy SpatialReference object is projected or geographic use the property type: geoSR = arcpy.SpatialReference(4326) print geoSR.type Geographic projSR = arcpy.SpatialReference(28356) print projSR.type Projected


3

Every set of coordinates stored inside SDE.ST_GEOMETRY is stored as a compressed array of 8-byte long integers. The IEEE floating-point to integer conversion is performed by subtracting the coordinate reference X_OFFSET (or Y_OFFSET, or Z_OFFSET, or M_OFFSET) and multiplying by the XYUNITS (or Z_SCALE or M_SCALE). The process is reversed when querying for ...


3

The short answer is no, the projection used by the USGS varies with product (map series), application (paper vs web vs GIS data), and department/region/whatever. If you really want some detail, they publish a document on projections called Map Projections: A Working Manual you can find at http://pubs.er.usgs.gov/publication/pp1395


3

To find out the right CRS, create a new project in QGIS with project CRS set to EPSG:3857, load Google or OpenStreetMap background from the Openlayers plugin, and look where your data is placed. If you set the Layer CRS of your data to EPSG:32749 WGS 84 / UTM zone 49S, your data will be placed in the right position (at least the same place a Google search ...


2

The +datum=nad27 parameter overrides the +towgs84 parameter. GDAL can only do grid shift, or Helmert/Molodensky transformation, but not both. Since the grid is more correct in most cases, the developers decided to skip the 3-/7-parameter transformation if both options are given. The transformation for NAD is stored in several grid files, which can be found ...


2

NAD27 EPSG:4267 and WGS84 EPSG:4326 are both CRS with lat/lon degrees. The extent of your layer is in a projected CRS, but the projection information does not reflect that. The most common pitfall in QGIS is to use Set CRS for Layer, which changes the CRS, but not the coordinates. You have to switch that back, or delete the layer and reload the original, ...


2

I think there may be a bug in QGIS save as. This is from QGIS 2.6.0 (Brighton): The easiest way to export a shapefile to a new coordinate system in QGIS is to right click on the shapefile and select 'save as' then in the dialog select Selected CRS which pops up a dialog and then select the 'to' CRS (in your case WGS84): Using the method employed in ...


2

In Settings -> Options, CRStab, select Prompt for CRS for new layers. Then you can choose WGS84 when loading the delimited text file. The other file should remain in BNG. Don't use Set CRS for Layer to change it. This will NOT reproject your coordinates. Instead, use Save As... on the delimited text layer, choose a different filename and BNG as CRS. ...


2

I just entered the coordinates into Google maps. If you change them to 35.205357, -111.59330 it puts you in the Flagstaff area. So The coordinates may have just had their decimal places in the wrong places or missing.


2

Vincenty's formula (ellipsoid based) is more accurate than haversine (sphere based). Also, lat and long are usually expressed in degree, but your coordinates are not in 0-180, therefore you could be in another system than expected.


2

PostGIS typically expects coordinates in longitude-latitude or E-N order. Looking at the second example from postgis.org/docs/ST_AsGML.html, it seems there is some flipping of coordinates: -- Flip coordinates and output extended EPSG (16 | 1)-- SELECT ST_AsGML(3, ST_GeomFromText('POINT(5.23423 6.34535)',4326), 5, 17); st_asgml -------- <gml:Point ...


2

I would prefer EPSG:3035. The ESRI codes might not be available on all platforms: EPSG:2163 has a different lon_0 leading to a distortion of the map:


2

In QGIS, goto Settings -> Custom CRS, and Copy from existing CRS. take a lcc projection based on WGS84, like EPSG:3762 +proj=lcc +lat_1=-54 +lat_2=-54.75 +lat_0=-55 +lon_0=-37 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs and replace the values to your system: +proj=lcc +lat_1=17.5 +lat_2=19.5 +lat_0=12 +lon_0=-102 +x_0=2500000 +y_0=0 +ellps=GRS80 ...


2

Those input points are not in urn:ogc:def:crs:OGC:1.3:CRS84, since that is (roughly) WGS84 lon / lat, and (taking the first point): [ 383707.21875, 9211513.0 ] is not a reasonable lon / lat combination. What QGIS is (probably) doing in converting that point to -52.78125,9211513.0 is taking 383707 and wrapping it around a few times (383707.2185 - 1066 * 360 ...


1

Actually it would work as both are about ~~~~ the same latitiude but use the Euro version http://spatialreference.org/ref/esri/102013/


1

KML coordinates are in EPSG:4326 by definition. WKT lacks any concept of CRS whatsoever, encoding just the geometry type and its coordinates. So there is nothing within the format's themselves that would allow you to force coordinates into EPSG:4326. However, as virtually all other terrestrial coordinate systems will use meters (or incredible, as it may ...


1

You haven't defined your spatial reference. Your tool has passed a spatial reference object to your script as a parameter, but you script does not do anything with it. Simply passing it to your script does not define the spatial reference. 2 options: Don't pass a spatial reference. Instead set the Output Coordinate System in the Environments... -> Output ...


1

Finding the center is not as simple as you think. take an example square in EPSG:4326: Transform it into World Mercator, and the center is somewhere else: In Lambert conformal conical, it is not yet a rectangle: And same for azimutal equidistant: So be careful if you think of a "simple" rectangle and its center point. The world is not a plane! My ...


1

Thanks Joseph and AndreJ for responding. Just in case anyone reads this and is interested, I found another work around. I loaded the delimited layer (which had the lat longs), saved it with a CRS of British National Grid. Then reopened this layer and created a query where I created 2 new fields, one with the x coordinate and the other the y coordinate (in ...


1

The latitude value could be 35 20 53.57 while the longitude value could be -111 59 33. Or they could both be decimal degrees, with the appropriate insertion or change of position.


1

It sounds like it would be more practical to make a polygon if you need a very wide, geographically consistent "ribbon." I suggest that you buffer your original line and style that instead. If you play around with styles you should be able to hide the fact that it's a polygon rather than a line.



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