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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1answer
34 views

What projection to use to get a game map into QGIS?

I have built and maintain a SWTOR game map atlas. At the moment, it's all static jpg maps, but I would like to get the info into an actual GIS software to get more functionality and make my website ...
0
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0answers
18 views

reproject satellite orbit values from irregular grid to regular grid

I have a ncdf file containing measurements covering a satellite orbit. The ncdf contains the corresponding latitude / longitude fields but they ar irregularly spaced. I tried rasterizing the values ...
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0answers
12 views

QGIS to Leaflet Projection Weirdness

I've been using the mmqgis tool to create a hex grid. It loads up in QGIS looking good, but when I save it as geojson and load it up in leaflet it gets stretched (see attached). It starts life as ...
0
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1answer
20 views

ArcGIS: Goode Homolosine Projection and Inconsistent Extents

I recently posted about a problem in ArcGIS using the Goode Homolosine (Land) projection with the Project Raster tool HERE. The problem was related to a bug with that tool, and a workaround solution ...
2
votes
1answer
406 views

USGS GeoTiff extent via GDAL

I have 2006 land cover GeoTiff from the USGS site (for a county in VA, USA). The projection is Albers Conical Equal Area Units. The download came with an HTML metadata file that tells me the geo ...
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1answer
29 views

Copy GeoTIFF metadata to TIFF using ArcPy

I have conducted some image manipulation on GeoTIFFs in a program and the resulting TIFFs now have no spatial information attached. Their x,y origins are (0,0). Since these processed images are of ...
2
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1answer
597 views

Help converting projection/coordinates to Google Earth

I'm trying to program a GPS style tracker for a simulation game but I'm having a hard time figuring out how to transform the game's coordinates into Google Earth's. The game's world is flat and has ...
2
votes
1answer
858 views

Converting shapefile in NAD27 from meters to decimal degrees to match xy data?

I have a shapefile of a boundary (polygon) that has the following projection: NAD_1927_UTM_Zone_11N Projection: Transverse_Mercator False_Easting: 500000.00000000 False_Northing: ...
2
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4answers
775 views

How to find and apply reprojection parameters?

I have a data set in one projection, and a shapefile in another, and I am trying to combine the two. I am using Python. I apologize for posting a "help me transform coordinates" question on this site ...
2
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1answer
507 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
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2answers
270 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 ...
24
votes
3answers
583 views

Why are Data Projections relevant?

Why is it useful to store data in unusual projections and datums? I understand the value of projections as output constructs, because of distortion, etc: that much is justifiable. However, I don't ...
4
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1answer
53 views

How to center a user-defined CRS on an area of interest?

My study extent in central Iran straddles two UTM zones (39 and 40): I would like to create a user-defined CRS in Transverse Mercator projection with central meridian inside this area. Through ...
6
votes
1answer
573 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
38 views

Projected raster data has inconsistent extent but not shapefile

I want to calculate the average value of a raster file within each polygon boundary of my shapefile. Because I want to preserve area I wish to use the Goode Homolosine (Land) projection. The original ...
1
vote
2answers
648 views

How to create a Winkel-Tripel map of countries with different colors?

I need a good quality rasterized world map, Winkel-Tripel projection, in which all countries have different (random?) colors. No borders, text, grid or anything else on the map. Is GIS the right way ...
0
votes
1answer
37 views

GDAL -SQL or -where options

ogr2ogr -overwrite -t_srs EPSG:3978 -f "ESRI Shapefile" -sql "SELECT * FROM 'Layer Name' WHERE FIELD_NAME = 'A CLASS'" dst.shp src.shp help me out here - looking to 1) reproject a shape and 2) ...
2
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1answer
44 views

Proj4 for EPSG3857

I am using leaflet and the R library sp. The CRS from my leaflet map is EPSG3857 - WGS84 Web Mercator. I am retrieving the coordinates of my current map view with getBounds(). For further calculations ...
0
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1answer
555 views

Transforming between epsg:3857 and Google Maps Tile coordinates

Hio, I used to use a simple python project (https://github.com/hrldcpr/mercator.py) to convert between wgs84 and google maps tile coordinates. This project doesn't have a license, and looks like it ...
0
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0answers
30 views

Using the projection of a layer variable to project another in ModelBuilder in ArcGIS (vector version) [closed]

I have several shapefiles in a folder (Folder X) with different coordinate systems (Proj 1 - eg. SAD69_UTM_Zone_21, SAD69_UTM_Zone_24) and another shapefile (shapefile 2) with another specific ...
2
votes
0answers
28 views

Converting from flat earth to WGS84 with python

I'm looking to move from basic 2d Cartesian coordinate system into WGS84. I know my starting coordinates, however all intermediate points are x/y/z points. of an origin 0,0,0 . Mathlab has a ...
0
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1answer
283 views

Displaying a map in EPSG:26915 projection in open layers 3

My GIS experience is limited to having worked on several Geospatial Humanities projects. That is to say that I still struggle significantly with the technology (and terminology) in getting to my goal. ...
2
votes
3answers
51 views

How to find the extent of (many) EPSG CRSes?

I want to map the geographic extents / bounding boxes of a lot of EPSG CRSes. At least, those with a rectangular geographic extent. For example, take epsg:2004, visiting that page shows the extent ...
0
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2answers
28 views

How to define a coordinate reference system with rotation in GeoServer?

I am using GeoServer and have a layer in EPSG:900913 ("Google Mercator"). I need to "rotate" the map around certain point (say, 1500000, 7000000) by certain degree (say, 30 degrees clockwise). How ...
0
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1answer
29 views

How to convert shapefile of India into a system with longitude and latitude system?

I have two shapefiles of India. One is without PoK and other is with Pok. I want to convert the shapefile of India with PoK into a co-ordinate system with longitude and latitude (same as without PoK). ...
0
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0answers
17 views

Matching d3.js geo projection with pyproj Proj4

I am having trouble figuring out the correct notation for Proj4 projections with pyproj. I got the following projection in d3.js and I want to match it with pyproj on my backend to send a background ...
10
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5answers
180 views

Fisheye-like projection

I need a special projection for the purpose of effective presentation on a poster. I'd like to present the study area (Czech republic) in a context of whole Europe in such a way, that the Czech ...
0
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0answers
22 views

Project Raster: Resampling

Is this (optional) resampling technique in the Project Raster tool only being used if changing the grid resolution (cell size)? Or should I always select bilinear (or cubic) for continuous data even ...
1
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0answers
33 views

Projecting a world map on 6 segments to print on ball

Working with QGis and data from Natural Earth I would like to prepare a world map (1:50 000) for a globe that can be printed in 6 segments, which glued together build a ‘sphere’ (ball) according to ...
9
votes
2answers
201 views

Why do I get correct area and intersect area when use wrong projection?

I need to calculate areas and intersection areas for polygons (some real geographical objects like lake, city, country, e.t.c.). Polygons located in California, New Zealand, Russia.Anadyr, Sweden All ...
0
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0answers
26 views

Geographic Coordinate System NAD 1983 vs Projected Coordinate System NAD 1983 & Projections

I am working on a project utilizing free data from http://www.pasda.psu.edu/, specifically data from PennDot, 2015 Pennsylvania County Boundaries ...
1
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1answer
36 views

How should I work with Layers with different projections in openlayers-3?

I'm using openlayers-3.8.2. I have some ol.layer.Tile layers and ol.layer.Vector layers. The projection of ol.layer.Tile layers and ol.layer.Vector layers are different. ol.layer.Tile layers work with ...
2
votes
2answers
47 views

How can I convert points in EPSG:2956 to EPSG:4326 with pyproj?

I have some points in EPSG:4326 -110.28879750 64.46310187 405.49938863 -110.28879359 64.46310086 405.45967110 -110.28880175 64.46310446 405.93823604 -110.28880245 64.46310258 405.48060850 ...
0
votes
1answer
252 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
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2answers
957 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 ...
1
vote
1answer
58 views

Converting from kilometers to degrees distances?

We have geometries in a Postgis database with SRID WGS84 and we have found lookups directly in degrees to be much faster than in kilometres, because the database can skip the projections I would ...
0
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0answers
25 views

raster data and polyline shapefile do not line up

I am working on an ArcMap .mxd encompassing the state of new mexico. I have a shapefile of the state boundary with the following coordinate system GCS_North_American_1983 WKID: 4269 Authority: EPSG ...
1
vote
1answer
14 views

How to get geodetic area? rgeos::gArea doesn't seem to work. Or area-preserving projection

I need to get an area of different polygons at continental scale (like third of Africa etc.). Usual functions like rgeos::gArea work only in the projection units. Is there any function which works ...
0
votes
1answer
15 views

Measuring different values in latlong Geotiff whether OTFR enabled or not

I'm using a GeoTiff file in QGis that has no projection per-se (it uses lat-long coordinates) and WGS84 datum. Further it has an x pixel size of 2.40475e-07 degrees and a y pixel size of ...
2
votes
2answers
61 views

Is there a way to get undistorted maps in R (when using the OpenStreetMap package)?

When I download a large map within R (using the OpenStreetMap package) and I reproject the map (ideally to +proj=longlat), the map will always turn out distorted, making country labels etc. near the ...
1
vote
1answer
202 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
2answers
274 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 ...
0
votes
1answer
29 views

Map Projection - Why don't we draw things out

I have been reading about different map projections and kind of understand where the problem lies. And also, most of the problem was that the old cartographers did not have any other tool other than ...
4
votes
1answer
143 views

How do I find/define a projection that gives me exact relative positions inside an area?

Assuming that a set of positions are all inside a 5km square area: How do I find/define a projection to reproject the positions, so that the relative positions between the now reprojected positions ...
0
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0answers
43 views

How to choose a projection for area measurement on building to continental scales?

I have many geographical objects described as polylines, polygons, multipolygons. All objects are in WGS84. Object could be: a building, stadium, park, street, highway, city, state, even country and ...
1
vote
1answer
29 views

Atlas with different projections in QGIS

I have created an atlas -- i.e. a map with a layer defining some regions of interest -- in QGIS. I can render maps of each region using the "atlas" feature of the print composer, but I want to show ...
0
votes
3answers
80 views

How to set a coordinate transformation GRID

Does anyone know how to set a coordinate transformation in qgis so I can measure the distances in meters or kilometers? If anyone has a clue, would be just great. Thanks!
2
votes
3answers
285 views

How are ESRI WKT projections different from OGC WKT projections?

Does anyone know the precise list of differences between esri wkt and ogc wkt projection format strings? I know there are various tools to help convert from esri wkt to ogc wkt, incl gdal utilities ...
3
votes
2answers
1k views

How to understand GeoTIFF tags?

I'm trying to understand GeoTIFF info, but not getting far. For instance, using listgeo with one file I can get this output: Geotiff_Information: Version: 1 Key_Revision: 1.0 ...
0
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1answer
36 views

MapInfo Point Object Dialogue is different to Info Tool's Transformed XY

A MapInfo Professional 11.0.3 user has re-projected data from AGD84 Zone 50 to WGS 84. However when they select a point and look at the point objects's X and Y, they are different to what's reported ...