Hot answers tagged

10

From the links posted as comments I identified a couple of misconceptions I had about projections and gathered this quick summary. It should be mentioned that many projections don’t truly preserve any attribute. Their intent is typically to minimize all types of distortion thereby not eliminating it in any specific property. Jack of all trades, master of ...


7

The second layer seems to be in degrees, although the SRS tells something else. So you might set EPSG:4326 WGS84 with Set Layer CRS. The result looks reasonable:


5

Solved: My map's data frame is in NAD_1927_StatePlane_New_Mexico_East_FIPS_3001. When I added the NAD83 UTM data I had assumed it was spatially accurate "on the fly" not knowing that, as @Vince, pointed out, when using "on the fly" projection for NADCON the transformation must be specified manually. After re-adding the NAD83 UTM data and manually ...


5

I think these are Northern Irish postcodes. Confirm this by checking the code of those in the sea. There's probably also other NI postcodes overlapping England and Wales, and wrongly located. Do you have Belfast (BT) postcodes? If you are using OS CodePoint data, then there's a country code field. Any locations coded as Northern Ireland have coordinates in ...


4

I suggest to use UTM zone 35. The points fall inside the Zambia borders: For UTM Zone 34 and 36, the points would be outside of the country, shifted horizonatlly into the next UTM zone. The "Grid" could be some local kilometer-wide grid for finding streets and places. It seems to be build from a Northing coordinate, "c" and an Easting coordinate in ...


4

Zambia falls in the UTM zones 34 and 35 (quick check on Google Earth). The grid most probably refers to a grid of map sheets. Looking at the X in the coordinates, the points should fall within zone 34. The X in zone 35 does not go over ~684,000 (again, this is based on looking at GE). My answer is based on the information you provided and looking at GE. ...


4

This is the Lo system used in southern Africa. You mentioned that it's Lo 19/WGS 84. I suspect it's really Hartebeesthoek94 / Lo19. Hartebeesthoek94 should be almost equivalent to WGS 84. The EPSG code, or well-known ID (WKID), is 2048 but Esri software doesn't support that WKID because the axes order and directions are positive west, positive south and ...


3

You've got so many lat-long points to georeference it probably doesnt matter much what you use. I just created eight points at some graticule grid points and warped the raster to EPSG:4326 (lat-long). The results look pretty good. If what you really wanted to do was assign the correct CRS of the original image to it then you'd have to work out what the ...


3

Your assumption of linear conversion is wrong. In Transverse Mercator, only the central meridian is straight northward, all others are bended. So 11.5 vs 12 degrees makes a difference. Besides Gabon 2010, there is a Gabon 2011 coordinate system, with this proj.4 parameter string: +proj=tmerc +lat_0=0 +lon_0=11.5 +k=0.9996 +x_0=1500000 +y_0=5500000 ...


3

I suggest to remove projection information in R output raster and open it in ArcGIS. If successful, define projection from within latter. I applied this trick with vectors coming from MapInfo to ESRI products. Slight difference in projection naming by these two packages had devastating result with points being 200 m away from their true position. Good ...


2

This should work: crs = originalLayer.crs().authid() # without () after originalLayer layer2 = QgsVectorLayer("Point?crs={0}".format(crs), "auxlayer", "memory")


2

Import your csv file into QGIS (Layer > Add Layer > Add Delimited Text Layer...) Select the relevant CRS if prompted If not prompted, right-click the point layer, select Save As... then choose ESRI Shapefile as format, and select the relevant CRS: Note: always use the Save As... option when converting to different a CRS.


2

las2las flightline_002.las --a_srs EPSG:32632 doesn't modify flightline_002.las. Rather, it creates a new file called output.las with the spatial reference information. output.las is the default value of the -o [ --output ] option available in las2las. To specify the new filename, use the following construction: las2las --a_srs EPSG:32632 ...


2

Those are probably geographic coordinates, probably WGS84. Try it with http://projfinder.com/


1

No. Leaflet does not implement fancy reprojection. You will have better luck if you manually reproject your data from EPSG:4326 into EPSG:3857, and then use the EPSG:3857 coordinates into a Leaflet map with CRS.Simple. My tool of choice for reprojections is ogr2ogr, although you can do it in javascript only by using proj4js.


1

Do they both have a defined coordinate system? I think this occurs because although Arc can project data on the fly, this does not apply when the data is in two different coordinate systems or datums, such as NAD 1927 vs NAD 1983. You need to apply a transformation. See related. I would recommend choosing a coordinate system and projection, and re-project ...


1

Typically, if there is no Coordinate System indicated, a local datum is used. When i draw those, I look for statements in the legal description that indicate what the local datum might be. This could be, for example: Commencing at the southeat corner of Soandso's Addition, as the same is platted and recorded in the office of the Recorder, Thence North ...


1

Looks like ESRI decided to define their own projection parameters: http://osgeo-org.1560.x6.nabble.com/Question-about-Krovak-projection-and-ESRI-XY-Plane-Rotation-parameter-td4291471.html There has also been some discussion on the GDAL list recently: http://comments.gmane.org/gmane.comp.gis.gdal.devel/42132 I suspect the raster package is applying some ...


1

Another way to work with the images using the GUI is: First in a new project add the .hdf as a raster and select which band do you want to work with. QGIS will set a new user defined CRS with a number, for example in my case USER:100008. Go to Raster>Projections>Warp(Reproject). You will reproject each one of the bands given an different output name for ...


1

I have recently had to perform the same transformation. I picked apart the formulas in the spreadsheet at http://www.ga.gov.au/scientific-topics/positioning-navigation/geodesy/geodetic-techniques/calculation-methods#heading-4 and have put together a Matlab function which can handle this, which is also vectorised to help chug through as many coordinates as ...


1

EPSG:28992 is projected system, not geographical so you cannot call SetWellKnownGeogCS() for it. You need to define both ellipsoid (GeogCS) and projection method (ProjCS) for projected systems. For UTM projection you can set both explicitly: proj = osr.SpatialReference() proj.SetProjCS("UTM 30N (WGS84)") proj.SetWellKnownGeogCS("WGS84") proj.SetUTM(30, ...



Only top voted, non community-wiki answers of a minimum length are eligible