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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3
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2answers
136 views

Which SRIDs to use for what tasks?

I try to understand the idea behind the different Spatial Reference Identifiers. I understand that the different SRIDs identify different projection views on the earth and that they are important for ...
5
votes
2answers
222 views

Coordinate/projection system issue in ArcGis 10.3

I am new in this community and I am also a new user of ArcMap. I am facing a problem, my shapefiles are in a GCS WGS 1984 and I have to add a new shape file that is in a projected coordinate system ...
1
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0answers
47 views

Sinusoidal Projection and ArcInfo Sphere Datum Woes

I am using published forest loss data (found here: http://glad.geog.umd.edu/indonesia/data2014/index.html) that uses the ArcInfo Sphere datum with a sinusoidal projection. I am seeking to transform a ...
1
vote
1answer
91 views

Bringing multiple non-projected CAD .dwg files over to ArcMap as a projected ESRI .shp

Is there a streamlined method to bring over CAD .dwg files that have unknown coordinate systems into ArcMap as ESRI .shp files and project the coordinate system of each new .shp accordingly? I have ...
2
votes
1answer
33 views

Why does not equal computing line in `OpenLayers` with `ArcGIS` when i use measure control?

My map projection is: "EPSG:900913" ,Display projection is "EPSG:4326" and units is "m", however does not equal the length is calculated in OpenLayers with ArcGIS, in fact Openlayers show the length ...
1
vote
1answer
90 views

Understanding precision of ArcGIS geodatabases?

I would like to know how precision is handled in ArcGIS software. Is it using a real Computer Algebra System engine, an arbitrary precision library or do others tricks to handle precision ?
2
votes
1answer
127 views

How to make slope map from elevation map in Lat/Long?

I have an elevation raster map of the world, in Lat/Long. When I make a slope map, the results of the raster cells will be either 0, or values close to 90. The problem seems to be that the Slope ...
2
votes
1answer
113 views

Natural Earth doesn't render well in Robinson World projection

QGIS Pisa 2.10.1 Mac Pro, Mac OS I don't seem to be able to create a simple World Map using the Natural Earth Dataset and the Robinson World projection, unless I zoom in. What could be the problem?
0
votes
1answer
134 views

Use lamber 93 imageOverlay with leaflet on top of OSM tiles layer

I'm trying to use a lambert 93 image overlay on top of an Open Street Map title layer. var map = L.map('map'); L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', { }).addTo(map); var coords = { ...
1
vote
0answers
59 views

Data not showing in QGIS when connecting to Oracle

I have an Oracle XE 11g spatial database that is connected to a web map. All the layers of the web map are stored in the database and they work just fine. I sometime need to edit some of the layers in ...
0
votes
0answers
69 views

Does Leaflet handle TopoJson in OSGB EPSG:27700 projection?

I already have a Leaflet map showing custom base map tiles in British OSGB projection, EPSG:27700 (using the Proj4Leaflet plugin). I would like to overlay some nationwide admin boundary data in the ...
0
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0answers
44 views

Old MIller projections Bipolar Oblique Conic Conformal/Oblated Stereographic definitions?

I'm attempting to georeference and warp some old toposheets that are various old projections including the following: Miller Oblated Stereographic Projection Bipolar Oblique Conic Conformal What's ...
2
votes
3answers
329 views

How to create a Projection from a CRS string using pyproj?

I'm trying to convert between two coordinate systems using pyproj: import pyproj p1 = pyproj.Proj("+init=EPSG:4326") p2 = pyproj.Proj("""PROJCS["NAD27 / California zone II",GEOGCS["...
1
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0answers
48 views

GPS point elevation vs Contours layer elevation

I have some survey grade GPS points whose elevation is approx 55 feet lower than my contours layer elevations. I am using 1 ft contours and comparing point elevations with contours in the same ...
2
votes
3answers
310 views

What is the altitude difference between WGS84 and NAD27 Zone II?

I have a point cloud in a piece of software and have exported the point in both WGS84 and NAD27 State Plane California Zone II (in US survey feet). The WGS data looks like this, with elevation in ...
4
votes
2answers
362 views

Map projection process for three-dimensional point cloud

I have some points given in ECEF coordinates (or LatLongAltitude based on WGS84, which is interchangable in my understanding). Currently I am working on a mapping software which allows to visualize ...
0
votes
0answers
31 views

Project (Data manager) plus Add XY results in new data being rotated

I have point data in decimal degrees. When I want to convert to local UTM data I have going through the usual Project (Data Manager) to project from LAT/Long to UTM and then when I add XY to the new ...
0
votes
1answer
43 views

Batch reproject shapefiles in subdirectories

I have a catalog tree and in every folder I have a number of shapefiles, images and mxd files. The shapefiles are all in Greek Grid projection system (EPSG: 2100). What I want to do is to batch ...
1
vote
2answers
136 views

Why does the OpenLayers plugin override the predefined projection?

What I am trying to say is: You import a shapfile into an empty QGIS and the QGIS environment gets the projection system of the imported shapefile. You import another shapefile into QGIS. The ...
0
votes
1answer
35 views

Reproject OpenLayers.Layer.OSM

In my map a set projection and displayProjection as EPSG:3763 and i can see my vector layers...they are EPSG:3763 Projections. Now i need a simple map behind my vector layers and i put this layer: ...
0
votes
0answers
44 views

How to get a mercator projection from a “disk photo”

I'd like to build a real 3d globe of Pluto using latest images made available from New Horizons. I know how to convert a mercator projection into a "12-gores" projection, suitable to be glued over a ...
0
votes
1answer
131 views

Are ArcGIS' UTM zone designations simplified?

I was recently given a document showing the UTM zones as they appear over the whole Earth. Each zone is 6 degrees longitude by 8 degrees latitude. A numbering system proceeds from 1 to 60 from -180 ...
0
votes
1answer
63 views

What is the type of EPSG of longitude/latitude (not Point) co-ordinates?

I want to know that what is the type of projection (900913, 4326 or so on..) of long/lat co-ordinates. I happen to come across a slight confusion while querying planet_osm_lines when I dump (...
0
votes
1answer
239 views

Shapefile extent units in decimal degrees but values in meters

I have a shapefile that had its geographic coordinate system defined as the projection NAD 83 UTM Zone 18. The scale of the layer was correct but it was at the wrong point in space. I redefined the ...
3
votes
3answers
108 views

How to overlay a map of Europe on a map of Australia?

I'd like to overlay the cities of Europe on Australia for distance/size comparison purposes using QGIS and I'm wondering how best to achieve this while preserving distance between the European cities?
2
votes
1answer
357 views

Create Circle and Marker on Click in OpenLayers

I want to create a marker and buffer around it with a given radius on map click event. Marker is displayed successfully but the polygon doesn't display. I guess there is problem in projection setting. ...
0
votes
0answers
58 views

Setting units for arcpy fishnet tool, given unprojected input

I'm trying to use arcpy to create a grid over each of a large number of metropolitan areas across the US. I'm iterating over each metro and trying to create a grid over each one using the "fishnet" ...
0
votes
1answer
54 views

Getting wrong values trying to convert to a latitude longitude system

By using listgeo I got the following information: PCS = 31468 (name unknown) If I am not mistaken this translates to DHDN / 3-degree Gauss-Kruger zone 4, and by using this site I got a proj4 string:...
1
vote
1answer
160 views

Using OSGB (ESPG: 27700) projection in Openlayers with MousePosistion

I am trying to display Ordnance Survey Grid references (ESPG:27700) on a set of BaseMaps with the MousePosistion control. From looking through the OpenLayers samples and this forum samples I have ...
1
vote
1answer
59 views

Choosing projection for calculating 2D 3D area in New Zealand?

I'm trying to use Surface Volume tool in ArcMap to calculate 2D and 3D area of a catchment. What would be the best projection to use and how do i check the maximum error of the estimation?
3
votes
1answer
140 views

Tilted projection in QGIS

I'm trying to add tpers projection as a custom projection in QGIS 2.10.1 In the Custom crs dialog I'm adding the proj.4 text: +proj=tpers +h=500000000 +lat_0=19 +lon_0=99 +x_0=0 +y_0=0 +a=6371000 +b=...
0
votes
0answers
31 views

Projection Discrepancy

I'm creating a system that pulls Longitude/Latitude data from the MapQuest hosted Nominatim service. I'm using OpenStreetMap/OpenLayers to display markers on a map. In order to compute the location to ...
3
votes
1answer
111 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
votes
0answers
41 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 ...
0
votes
0answers
33 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 4326,...
0
votes
1answer
47 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 ...
1
vote
1answer
141 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 ...
4
votes
1answer
81 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 ...
1
vote
1answer
259 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 ...
2
votes
1answer
153 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
votes
1answer
82 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
votes
0answers
97 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 ...
2
votes
3answers
115 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 (...
1
vote
2answers
224 views

Defining 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 ...
1
vote
0answers
82 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 ...
0
votes
0answers
77 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 ...
5
votes
1answer
302 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 ...
0
votes
0answers
71 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 http://www.pasda.psu.edu/uci/MetadataDisplay.aspx?...
12
votes
5answers
312 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 ...
2
votes
1answer
638 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 ...