A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane
1
vote
1answer
441 views
Generating Map Tiles for MGRS Grid Graticule
I'm possibly a bit out of my league here, but ready to get my hands dirty. I want to generate map tiles for a MGRS grid graticule similar to http://tiles.mapbox.com/mapbox/map/afghanistan-mgrs.
I ...
4
votes
1answer
757 views
Distances in {Plate Carrée projection - EPSG:4326 - WGS84}
So,
"4326 is just the EPSG identifier of WGS84" [3], indeed http://spatialreference.org/ref/epsg/4326/html/ says it is a GEOGraphic Coordinate System:
GEOGCS["WGS 84",
DATUM["WGS_1984",
...
2
votes
1answer
440 views
Projection ETRS89 (Ellipsoid: GRS80) 6-Degree Zone 33 to UTM33N - WGS84
Hi I'm having trouble to reproject a shape file in Qgis.
The projection is supposed to be "ETRS89 (Ellipsoid: GRS80) 6-Degree Zone 33" and I would like to project it to UTM33N - WGS84 (EPSG 32633).
...
2
votes
3answers
166 views
Are there WMS servers providing maps of UTM zones, actually in the zone projection?
There are lots of EPSG:4326 (lat lon) services out there but if one has to use an UTM projected map as base layer to display utm scenes, are there any WMS endpoints publicly available for that?
2
votes
2answers
202 views
C++ coordinate class that automates projection?
Can anyone point me to a C++ class for representing coordinates that automatically handles projection transforms? What I'm thinking of is something that would allow me to create vars that incorporate ...
1
vote
2answers
234 views
How to shift the Map a little bit?
I'm having trouble with two maps, both UTM33N/WGS84. They should be exactly on top of each other but there is a slight shift between them of probably a few hundred meters or so.
I Tried to adjust ...
1
vote
2answers
303 views
Re-initializing OpenLayers Map with different projection
Is it possible to re-initialize OpenLayers Map with a different projection ?
Scenario:
OL Map with projection 4326 is created, along with click, measurement, drawing handlers.
A button to switch to ...
2
votes
2answers
350 views
LonLat Points to Grid of Polygons in PostGIS
I'm going to preface this with it's my first time using PostGIS.
I'm starting out with a 5 km x 5 km grid cell in which I know the center point lon/lat (SRID=4326). I'm trying to create a polygon for ...
1
vote
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 & ...
1
vote
1answer
425 views
Reprojecting a shape to UTM33
I still have trouble reprojecting shape files :(
I would like to reproject it to UTM33N / WGS84 (EPSG 32633) I think the projection of the shape might be Pulkovo 1984/ Gauss-Krüger Zone 4 (EPSG ...
3
votes
2answers
508 views
How to calculate how long an arc second is for a given long/lat?
The title says it all, really. I am wondering what area is covered by a dataset which is one arc second wide.
Thanks,
Rob
1
vote
1answer
927 views
How to correctly specify coordinate system?
Using QGIS v. 1.9 (1.7 does not seem to be available for Ubuntu Linux 12.04), do the following:
Create new project, specify coordinate system by clicking on button in bottom right hand corner, ...
3
votes
2answers
478 views
Display two layers with OpenLayers at once
How can i display two layers with diferent projections at once? For example i have layer with EPSG:70076 and OSM layer.
3
votes
3answers
345 views
Convert Nasa's Blue Marble into a cubic projection
I'm looking for a free tool to convert the cylindrical projection map of the Earth's surface that you can get from Nasa (under the Blue Marble project):
...
3
votes
2answers
155 views
How do you change the prime meridian of a map?
I am working with the Natural Earth world map as a SHP file, but when I try to change the prime meridian (PRIMEM) of the coordinate system
...
5
votes
3answers
640 views
Using arcpy what is the most efficient way of projecting a selection from a large data set?
I have a large data set X(x1-xn) from which I must select consecutively the attributes A(a1-an) from X.fieldsSRC or X.fieldDST and project the selections.
I have a functioning arcpy script that does ...
2
votes
1answer
85 views
Is there an arcpy boolean check for whether an EPSG or prj is supported by arcmap?
I'm writing a tool and essentially I found out that arcmap defaults an epsg to 0 if it sees that the projection is not supported against the predefined projections.
2
votes
1answer
147 views
Automate database conversion from NAD83 to Web Mercator
A NAD83 database is updated daily while a Web Mercator clone is only update when time is available. Looking to automate this process of
Copying Layers
Projecting them to Web Mercator
Placing in ...
3
votes
2answers
501 views
How do I get the distance meter value between two geometries in PostGIS?
I have a simple question about calculating distances in PostGIS.
I would like to get the distance between two geometries. I am using this sid : 4269 in meters
what i am doing now is this : ...
0
votes
1answer
475 views
I can project from UTM (zone 10) into State Plane (Oregon), but I can't do the reverse — why not?
I have an air photo with the following xy coordinate system name:
NAD_1983_StatePlane_Oregon_North_FIPS_3601_Feet_Intl
and the following in the description field:
Projection:
...
1
vote
0answers
206 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 ...
1
vote
1answer
1k views
How to change the projection of a UTM-georeferenced raster in Quantum?
I have a project file in Quantum which contains some shapefiles and rasters that are properly georeferenced. However, I have started using GeoTiffs which are in UTM - WGS84 that don't seem to be ...
1
vote
1answer
337 views
When I import polygon kml layer, how do I change projection and offset to correct for GMT wrap?
I created a polygon in Google Earth and saved to kml. After importing as a vector layer, where the polygon crosses the prime meridian, the polygon wraps around the world.
So far, I have figured out ...
0
votes
2answers
2k views
How to create custom coordinate system in ArcGIS?
I have a series of control points with xy coordinates in both NAD83 UTM and in a local grid.
How can I go about creating a new projection file in ArcGIS 10 for the local grid?
Thanks
3
votes
0answers
238 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, ...
17
votes
7answers
513 views
Spatial reference for dummies?
Can anyone recommend a good reference or tutorial that explains the principles of spatial references, projections, and coordinate systems? We are a small team of programmers working with GIS ...
1
vote
0answers
110 views
How to show an array of 2d points/polygons in Polymaps (Cartesian coordinate system)
I need to display these 2d points/polygons (Cartesian coordinate system) on Polymaps with GeoJson layer.
I do not use the other layers.
Do I need to convert xy coordinates to the lat lon? If so, how?
...
2
votes
1answer
1k views
How to convert decimal degrees units to km in R?
I am trying to figure out how I can transform my unit of length from decimal degree to km when I import the following simple ArcGIS polygon shape. Ultimately, I would like to have this information ...
3
votes
1answer
549 views
How to perform datum transformation in ArcGIS server REST API exportmap
I have a ArcGIS server 10.0 mapcontext in one projection (swedish grid sweref99 TM) which uses its own datum, also named Sweref99 . When I use the REST API's map service export function I want to ...
2
votes
1answer
232 views
Is it possible to automatically set CRS of Rasters from PRJ file?
I am trying to learn my colleagues to display measured data (ASCII) in maps relatively easily. I can prepare project, color and symbology style for the point layer and background map.
I also found ...
1
vote
1answer
280 views
Looking for help identifying projections and reprojecting
Hi there at the new forum,
I'm still struggling with projections in qgis. The "Vogelschutzgebiete" reprojection worked. But these ones seem to be tougher:
...
0
votes
0answers
48 views
What projection is this [duplicate]
Possible Duplicate:
QGIS - Hell of time with CRS and vector intersect
The tax assessor parcels layer I referred to in my first post gives this as its projection:
+proj=lcc ...
10
votes
2answers
180 views
How do I determine the projection of a paper map?
If I'm reading a paper map how do I determine what projection was used to draw the map if such information is not explicitly labelled on the document?
Online it is easy to find resources (for ...
2
votes
2answers
680 views
Image tiling math
I've been looking at MapTiler for the logic on how to render an image
as tiles on a (google) map. Instead of storing the single tiles
locally in a folder structure I want to use Djatoka. I'm able to
...
1
vote
0answers
243 views
Geoserver tiles mismatch
I tried to get WMS tiles from geoserver like
/geoserver/gwc/service/tms/1.0.0/layername@EPSG%3A4326@png/15/19142/9530.png
or with another projection
...
3
votes
1answer
169 views
How would I go about re-projecting the Blue Marble raster maps into a robinson projection using free tools?
I would like to convert the NASA Blue Marble maps into a robinson projection.
2
votes
3answers
977 views
Rendering a shapefile with a custom projection in GeoTools
I have an image, a shapefile, and a method which can translate an x/y pixel location from the image into a latitude/longitude point or vice versa. I'm trying to use Geotools to render the shapefile on ...
2
votes
0answers
82 views
raster data expressed as percent
I downloaded NDVI greeness data from the USGS Integrated Vegetation Mapping Viewer. In the metadata it says that visual greenness values range from 0 to 100. My data is from the period ending 3/5/12 ...
1
vote
2answers
256 views
Geowebcache re-projection
I have one layer (raster geotiff image) published in geoserver with EPSG: 3011 projection. But I want this layer in EPSG 4326 projection for use it in google API web application. I have searched on ...
0
votes
2answers
60 views
Need Image with Sweref99_1800 projection/coordinate system
I need third party image tiles (probably world imagery) under sweref99_1800 projection and coordinate system (EPSG 3008). I found this link ...
2
votes
3answers
678 views
Why are the tile coordinates different in Google maps and Google earth?
I have a .NET application that typically uses the standard Google Maps JavaScript API V2. Within this application I am using a GTileLayerOverlay to add my own custom dynamic tile layer.
function ...
5
votes
2answers
1k views
How is EPSG:4326 data 'projected' in a 2D map?
I like to think I'm relatively well-versed in datums, projections, and coordinate reference systems, so if this is a stupid question I will suffer eternal shame.
OpenStreetMap data is stored in WGS84 ...
0
votes
0answers
63 views
Changing projection of base layer
normally we change projection of vector data for displaying it over google base map. Similarly is it possible to change the projection of base image tiles map? if yes, how we can do that, any ...
14
votes
2answers
536 views
Which world map projection allows comparing countries by shape and size?
The Mercator projection increases scale along with the latitude. Greenland seems larger than Australia, when in fact it is much smaller. The equal-area projections however stretch shapes away from the ...
5
votes
1answer
845 views
Mercator projection: problem with latitude formula
I'm trying to get the position of a coordinate on this map (source Wikipedia):
If I'm correct than the formula for the position of the latitude would be:
R * ln(tan(pi/4 + latitude / 2))
But ...
12
votes
3answers
5k views
Layers having the same coordinate system should overlap, but they don't. What's wrong?
I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
13
votes
1answer
1k views
How to define new custom projections in QGIS?
I'm trying to define a projection in QGIS. I want to add North America Albers Equal Area Conic. From the spatialreference site I copied the proj4 line:
+proj=aea +lat_1=20 +lat_2=60 +lat_0=40 ...
2
votes
1answer
559 views
How can I transform GCS_WGS_1984 to GCS_North_American_1983?
I need to convert a GCS_WGS_1984 data set to NAD_1983_UTM_Zone_14N. What transformation should I use?
2
votes
4answers
1k views
OpenLayers transform EPSG 27700 coordinate to Google 900913
Community,
I'm currelty capturing my mouse click event and trying to transform the coordinates into Long Lat. I need to get at the Long Lat as strings so I can build a url and throw it at Google ...
1
vote
0answers
126 views
I am getting a blank layer preview from geoserver after Quick Exporting my shapefile to postgis and then getting postgis to point to geoserver
What could be the potential problems? Looking at the layer's data fields/form the one thing that isn't filled is the Native SRS and its source, but I have already passed in the projection info as it ...
