A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane

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5
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2answers
112 views

Transformation parameters for Everest datum to WGS84

I have a shapefile with the following projection information: ...
1
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1answer
105 views

Lambert Conformal Conic Projection Inverse Transform after Fitting Ellipse to Noisy LLA Data

I'm using Python and Basemaps to convert some Lat Lon data to the LCC projection and back again. Since it is noisy data representing the footprint of a satellite, I am filtering it and fitting an ...
6
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3answers
135 views
+50

What coordinate system is this netCDF raster?

I obtained a netCDF raster file, but I couldn't get any metadata to get the name of the coordinate system the raster has been built on. The raster itself doesn't have any coordinate system embedded. I ...
6
votes
1answer
462 views

Determining Natural Origin for a GeoTIFF file (Lambert Conic)

I am trying to display an existing GeoTIFF file (from the FAA WAC set) in an application that requires the GeoTIFF NaturalOriginLongitude tag (FalconView 5.1.1). There are some older files in that set ...
1
vote
1answer
18 views

I can't get my OpenLayers radar overlay to display correctly

I've tried to overlay a radar image on my map so that I can show the current radar for the United states. However, whenever I load the map, I can't seem to get the projection to look correct. Here's ...
0
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0answers
15 views

Is there a formula for calculating 2D map distance from 3D information?

Using ThinkGeo, I have a Lat/Lon coordinate, and a distance of .1 miles. The .1 miles represents the radius of a circle and I'm trying to draw this radius around the lat/lon coordinate. The map units ...
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1answer
80 views
+50

How to update projection of layers in Geoserver using gsconfig

Im using following code to find projection of layer from geoserver.catalog import Catalog cat=Catalog("http:// localhost:8080/geoserver/rest") myResource = cat.get_resources(store='storeName', ...
0
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1answer
14 views

Why Geowebcache is locking all system?

My story is like this about geowebcache. I am useing geoserver 2.5.x and GeoWebCache version 1.5.2, build 1.5.x. OS is ubuntu. I can not found geowebcache.xml file in server. But there is a file ...
0
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2answers
43 views

I am looking for a direct long. to X lat to Y map of earth

Occasionally I like to drop raw coordinate data into excel and do a scatterplot. It comes out quite a bit like cylindrical projection but not quite. The distortion near the poles is a bit more ...
1
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2answers
503 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
4
votes
2answers
120 views

Why is the Google Maps circle shape not matching to the distance calculated with PostgreSQL?

I am running a PostgreSQL 9.1 Database with PostGIS 1.5 extension. Several coordinates are stored in there with type GEOMETRY (SRID 4326). I'm building a web-application with Google Maps Javascript ...
0
votes
1answer
107 views

Scaling x,y coordinates in proj4

This question was asked before, but without answer. Let's say we have mercator map with given resolution (for simplicity in centimeters). Now let's get coordinates of (lat,lon) = (50, 15): $ proj ...
0
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1answer
18 views

Overlaying two shapefiles and projecting one of them from Geographic to Projected Coordinate System? [duplicate]

I am trying to project a shapefile which is in Geographic Coordinate System i.e. Geocentric Datum of Australia 1994 to a Projected coordinate system i.e. Map Grid of Australia Zone 55 using GDA 94 ...
2
votes
1answer
101 views

Reprojecting MODIS Ice Sea Temperature products with gdalwarp

I have problems projecting MODIS Ice Sea Temperature (IST) products to EPSG:3031 (Antartic Polar Stereographic) using gdalwarp. The product I'm working with is MOD29E1D, documented here, p33: The ...
1
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1answer
17 views

Openlayers 3 circles from geojson not working with layer tile source different from TileWMS

I am working with openlayers 3 with a layer from mapbox or openstreetmap and I need to draw some circles on it. I am able to print the circles with a view with a projection EPSG:4326, but then I have ...
3
votes
0answers
23 views

Is there a way to expose Spherical Mercator Lat Lon in Google Map API?

The map tiles in the Google Maps are in Spherical Mercator projection (srid 900913), but in the API the methods report coordinates in Lat/Lon WGS84, e.g. map.getCenter(). Is there a way to return the ...
3
votes
3answers
198 views

Which equal-area projection to use for UK?

I have a bunch of UK polygons that are saved in my PostGIS database as WGS84 projection. I would like to calculate the area of these polygons using st_area. According to this answer I can save these ...
3
votes
2answers
2k views

Meridian convergence. True north, magnetic north and grid north

I'm having difficulty wrapping my mind around meridian convergence, the horizontal angular distance between true north and grid north. Say I want to determine if a feature lies to the east or west ...
3
votes
1answer
60 views

Openlayers 3 WMS Projection

I am working with both EPSG:4326 and EPSG:4230 in OpenLayers 3 and I am using my WMS service which only supports EPSG:4326 maps. What I need to do is show a map in EPSG:4326 and transform it to ...
1
vote
1answer
125 views

Trying to set NAD 1983 EPSG 102631 in QGIS

I was able to find the right coordinate system online NAD 1983 Alaska But now I don't know what to do. I can't find the coordinate system on QGIS. When I choose the one I think is correct it warps ...
1
vote
1answer
29 views

Coordinates freeze when I give a projection

I have recently begun to use arcmap and needed some guidance on a problem that I am facing. I have a district shape file with 200 districts with geographic coordinate system: GCS_WGS_1984. I need to ...
3
votes
1answer
18 views

Equatorial Scale

I have seen Equatorial Scale written along with the RF on the World Map in many Atlases, for eg., "Equatorial Scale 1:95 000 000". What does this Equatorial Scale mean and what is the significance of ...
1
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1answer
31 views

Parameters of Normal vs. Transversal cylindrical projections

I need to parameterize a cylinder that cuts the ellipsoid. One time in normal case   (eg. like Mercator) and one time in transversal case (eg. like Transversal mercator). So, in normal case the cut ...
2
votes
1answer
214 views

using PostGIS to calculate distance of a route over a large area

I'm new to PostGIS and looking to measure the distance of the Pacific Crest Trail which spans western North America from Canada to Mexico. I have a data set containing the lat lon and dates from GPX ...
0
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2answers
25 views

Unknown Coordinate System Cadastral?

I have point data from a proprietary source that came in a coordinate system I do not recognize. Here is an example: Lat: 35205357 Long: -11.15933 It looks like a combination of UTMs and ...
5
votes
1answer
702 views

Problems with lat long projection

Hi this seems like it should be an easy problem, but its been giving me a headache. I have a .xls spreadsheet with about 60,000 rows. Most of them have Latitude and Longitude. I simply want to ...
0
votes
2answers
53 views

How to link a shapefile with points to a shapefile with lines?

I have a shapefile with points (nodes) and a shapefile with lines (pipeline) which I have extracted from a water distribution network. I have been able to transform the points into the right ...
1
vote
1answer
41 views

QGIS 2.4.0 CRS reprojection creates empty files and goes generally nuts

I consider myself an intermediate GIS user but keep running in a problem with the newest QGIS version I cannot fix and wonder if it may be a bug or if I am just too stupid. The problem mostly centers ...
1
vote
1answer
102 views

Tiled raster image to be placed in an OSM/ Leaflet.js map

I have a mapoverlay in a custom projection which I need to add as a layer to an Openstreet map within a website. Since I was not able to change the projection earlier, I decided to manipulate the ...
9
votes
2answers
571 views

What happens to feature class when importing to feature dataset?

I am creating a model that needs to ensure that all input datasets end up in the same coordinate system (among other things). I was originally going to batch project all of the datasets whether they ...
9
votes
3answers
261 views

A global, grid-like projection for creating heatmaps

I'm putting together an application where I need to create a vector grid which will be used to store and display a heatmap. It has the following requirements: Can cover the entire planet. The vast ...
0
votes
0answers
18 views

Projection of COSMO-EU?

I have data points of COSMO-EU data stored in WGS84 coordinates. Now I try to transform them into coordinate system where the points becomming arranged to a regular grid. Does anybody knows the Proj4- ...
1
vote
1answer
45 views

Is there a way to change the QGIS default CRS?

I'm working in a UTM projection and bringing in dxf layers from a different program. The dxf files are all in the correct UTM coordinates already, but when I bring them in I need to change the CRS to ...
2
votes
2answers
375 views

How do I reproject one raster to match another's in GRASS

I have two raster layers, A and B, which have information about the same location but have different projections and datums. How can I reproject layer A to match the projection and datum of layer B? ...
0
votes
1answer
23 views

Creating a spatial reference in arcpy from projection name

I am using ArcGIS 10.2.2, Python 2.7. I want to create a spatial reference from the name of a projection, e.g. NAD_1983_BC_Environment_Albers, using the arcpy tool ...
0
votes
1answer
122 views

GDAL - projection from pixels to geo coordinates

I am using GDAL library in C++. On my dataset, I have obtained geo transform with GetGeoTransform to GT array (GCP is NULL). Than I use this values for this equation (Source): Xgeo = GT(0) + ...
1
vote
1answer
23 views

why am I getting a horizontal solid strip when projecting large image?

I am using Mapnik to create tiles on a tile server. I'm depicting sea level rise in North America using SRTM data, and it works fine in most of the continent. However, when zoomed out in my browser ...
2
votes
1answer
419 views

OpenLayers and custom Proj4 Projection

ok so I'm a newbee in using OpenLayers. I try to map some planetary data on my webMap server using OpenLayers. I defined a proj4 projection as follow: Proj4js.defs["MYDATUM"] = "+proj=longlat ...
0
votes
1answer
28 views

Converting datum?

I need to measure the distance (with the ruler) of points from two different layers. However, one layer is NAD83 and the other is NAD27. I also have a standard ESRI basemap downloaded. The issue I ...
0
votes
2answers
148 views

projection conversion from mercator to google maps format

Is this spTransform(Finland3, CRS("+proj=longlat +ellps=WGS84 +no_defs+ellps=WGS84 +towgs84=0,0,0 ")) the right way to project a shapefile with this projection coord. ref. : +proj=merc +lon_0=0 ...
2
votes
1answer
44 views

Python Geospatial Development Error

I'm working through some examples in the Python Geospatial Development book by Erik Westra. On page 439, about setting up a tile map server, he gives the following code for calculating a bounding ...
2
votes
2answers
46 views

Mapping Russia - Int'l dateline splitting polygon

I am having the issue where the International Dateline is splitting a polygon I am working with. I have a layer of the "Federal Districts" of Russia, and the eastern most federal district is being ...
8
votes
0answers
683 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, ...
5
votes
2answers
6k views

Coordinate system and projection for georeferencing Google Maps image in ArcGIS Desktop?

I have saved Google Maps image (not Google Earth) of area at latlon(17.692437,83.218689) by some method in jpeg format. It is an exact snapshot of the Google Maps. Now I need to geo-reference it to ...
1
vote
1answer
75 views

Definition of the WGS 84

Hi i'm having some trouble getting the following things straight with , does this make sense? EPSG:4326 WGS84 Coordinate system: WGS84 Datum/Ellipsoid: WGS84 Projection: longlat
3
votes
2answers
68 views

Influence of the scale factor on the projection

I'm currently reading documentation about map projections to understand the source code of the Proj4 project. The scale factor is named in a variety of sources I read. This sources explained its ...
1
vote
1answer
115 views

How to reproject from Clarke_1880_RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA?

I am unable to reproject Marseille shapefiles from Clarke 1880 RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA. I know that Clarke is a geographic coordinate system and it has no datum. I have tried ...
1
vote
0answers
41 views

How i can have the same xMin,yMin for vector files in Qgis 2.4

i have a .shp file(polygon) in EPSG:2100 - GGRS87 / Greek Grid and an other .shp(points) in the same system(EPSG:2100 - GGRS87 ) but different xMin,yMin. The first has xMin,yMin 583309.00,4152885.94 ...
2
votes
2answers
57 views

Is there an algorithm for transforming from CGCS2000 to WGS84?

Is there an algorithm that supports transforming from CGCS2000 coordinate to WGS84 coordinate? CGCS2000 is China Geodetic Coordinate System 2000. Any advice would be thankful!
2
votes
1answer
35 views

J2000 to WGS84 in QGIS?

How to transform Earth-Centered Inertial J2000 CRS to WGS84 CRS in QGIS? I searched J2000 in spatialreference.org, however nothing found. I don't know the proj4 string of J2000. Any advice would be ...