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

learn more… | top users | synonyms (1)

1
vote
1answer
28 views

Alternative to Web Mercator projection that does not look too small on phone?

My issue with Web Mercator as a projection to use online is that I think it gives people an unrealistic perception of space. Greenland looking massive is a good example. One benefit of Web Mercator, ...
3
votes
1answer
47 views

What is the real distance between positions?

I'm trying to figure out what gives me the most accurate distance between positions: Measuring distance directly (using Geod.inv)? Measuring distance in 2D (after transforming to a known projected ...
3
votes
2answers
71 views

What is a suitable map projection for the entire state of Idaho?

I am working with some sample GIS data for Idaho. The data is in geographic coordinates but I want it in projected coordinates. I am unsure how to address the issue of projection as Idaho crosses ...
1
vote
1answer
20 views

Polygon Surface Area Calculator in different map projection(s)

I'm simply looking for an online tool or a utility to calculate the surface area of the same polygon (i.e shapefile) in different projection (projected and geographic projection system) systems. It ...
3
votes
0answers
41 views

Choosing projection for routes that fall within two UTM zones? [duplicate]

I'm creating charts for routes that fall within two UTM zones; 30S and 31S. The offshore routes are in the Alboran / Balearic Sea - connecting Spain to Algeria. What projection should I use?
13
votes
2answers
7k views

API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty ...
1
vote
1answer
23 views

Using map units to define radius of point feature in styles in QGIS: not getting it right

I have a point feature in a map which is in EPSG32723 (WGS84 - UTM zone 23s) and I need to style it as follows: A center point in red and a circle below it which has a particular size in meters. I ...
2
votes
1answer
593 views

OpenLayers and custom Proj4 Projection

I am trying to map some planetary data on my webMap server using OpenLayers. I defined a proj4 projection as follow: Proj4js.defs["MYDATUM"] = "+proj=longlat +a=1740000 +b=1740000 +units=m +no_defs"; ...
0
votes
2answers
719 views

OpenLayers WMS - TypeError: this.resolutions is undefined

I'm trying to setup a map with WMS and WFS Layers by using Geoserver. However, when I'm combining WFS and WMS (with some Google basemaps) together in one map I got following error in Firebug: ...
3
votes
0answers
42 views

Wrong area using Albers Equal Area Projection in GRASS for Java, Indonesia

I am just getting to know GRASS 7.0 and I am struggling finding a good projection to work on a spatial analysis of Java, Indonesia. I am new to the forum, so if information's are missing for a better ...
0
votes
1answer
26 views

Projection of WMS in MapInfo

I am using the OSM open Roads WMS layer that comes included with MapInfo. I have noticed that when I load this layer the projection of the Map window changes to 'Popular Visualization CRS.' All the ...
2
votes
2answers
784 views

How to transpose the lat/lon coordinates of a shapefile?

I need X to be Y and Y to be X (switching lat/long) within the polygon shapefile. If it were a point shapefile I know I could simply reverse the lat/long or x/y parameter and import from a table. I'm ...
2
votes
2answers
103 views

are these two proj4 utm projection strings equivalent?

I have a list of proj4 calls. Some of them have one format and some have another, I've been told they are equivalent. Is that so? If so, which one should I use? for example, for ETRS89 / UTM zone ...
0
votes
0answers
5 views

The effect of setting the reference system as “Unknown” when building stereo block

I couldn't figure out what is the effect of setting the reference system as “Unknown” when building stereo block in Erdas.
1
vote
0answers
137 views

Transforming zonal and meridional velocity from regular lat lon to rotated lat lon?

Like in Transforming regular lat/lon to rotated lat/lon? that was asked before, I am working with climate data and I need to transform zonal and meridional velocities (u and v) from regular lat lon ...
1
vote
0answers
41 views

Are ellipsoid and datum the same? [duplicate]

Are the datum and the ellipsoid the same? What is a Datum? The Earth is shaped like a flattened sphere. This shape is called an ellipsoid. A datum is a model of the earth that is used in ...
3
votes
1answer
1k views

How to set Scale Factor for Lambert Conformal Conic (LCC) projection in ArcGIS Desktop?

The projection for my state according to my country's Mapping Agency is in a specific Lambert Conformal Conic (LCC) projection. They have given values for the following parameters: False Easting ...
3
votes
1answer
18 views

GCS and PCS data misalignment in ArcMap when zoomed in

I have a shapefile in NAD83 UTM18 which I need to get into GCS NAD83. I tried both loading it into an empty GCS NAD83 feature class directly and the "project" tool. The results are the same - the ...
1
vote
0answers
27 views

Projection Issues - OpenLayers / MapServer / NAD83 State Plane FT

I am having projection issues with OpenLayers version 2.13 with MapServer and the Proj4 library. Pulling layers in NAD83 State Plane Feet projections on top of an OSM or MapQuest Base Map in Google ...
4
votes
1answer
35 views

Importing ESRI:102091 Monte Mario reference system

I am trying to import a dataset generated by my local council (Turin, Italy). The data appears on the map but it's slightly shifted and it doesn't match the Open Street map layer that CartoDB uses ...
1
vote
0answers
22 views

Converting coordinate obtained from google maps to be used with gdal_translate in java or cs2cs?

this is a follow on question from Geo-Referencing an image from google maps with gdal_translate I am trying to get cs2cs to work but I am getting the following error. My command is as follows: ...
3
votes
1answer
53 views

Geo-Referencing an image from google maps with gdal_translate

I am trying to geo-reference an image using gdal_translate in a command prompt. Currently I have the following gdal_translate.exe -of GTiff -a_nodata 0 --config GDAL_DATA "Config location" -a_ullr ...
2
votes
2answers
46 views

Convert NAD_1983_Georgia_Statewide_Lambert to NAD83

All I have a ESRI generated shapefile that uses: NAD_1983_Georgia_Statewide_Lambert Here is the projection information: ...
3
votes
2answers
467 views

Loading projection along with raster in R?

Why the operation myraster = raster("test.asc") does not load the associated projection file test.prj located in the same directory as test.asc? Does raster() need a specific argument? It seems ...
1
vote
1answer
70 views

Transform an image with projection EPSG:4326 to EPSG:3857

I have an image with known boundary and projection EPSG:4326 and want to overlay it to openstreetmap using Leaflet.js. I have tried using function imageoverlay, but the image is not aligned with the ...
7
votes
2answers
3k views

what is the best way to programmatically convert between WKT and Proj4 string?

some shapefiles have a .prj file associated with it. and the .prj file contains the projection info of the shapefile in the format of WKT. Sometimes I need to convert WKT to proj4 string, and ...
1
vote
0answers
29 views

getting started designing satellite projection raster

How do I get started designing a map with a satellite projection like this:http://bl.ocks.org/joyrexus/6619251. So far using d3 I've created a map of North Africa w/ topojson and tiles from Mapbox but ...
8
votes
2answers
114 views

Convert a geotiff web-mercator into an azimuthal equidistant projection

I have a geo-referenced tiff file, in the web-mercator projection; and I need it converted to an azimuthal equidistant projection. I'm new to GIS and can't figure out how to do this. I'm open to ...
2
votes
1answer
97 views

Coordinates are not aligning

The two shapefiles (shp) are not aligning like they should (note the img). The layer and the two shp files have all the same coordinates - NAD_1983_StatePlane_North_Dakota_North_FIPS_3301_Feet The ...
2
votes
1answer
38 views

Map scale factor when converting from Mercator to Equirectangular

Lets say I have a map in Mercator projection, and I know top and bottom latitudes: topLatitude = 80; bottomLatitude = -55; I also know width and height of a map: width = 800; height = 500; I want ...
1
vote
0answers
25 views

d3.js Projection for Washington DC area

I'm making a small thematic map of the Washington DC area using d3.js. Everything I've tried "tilts" the square of DC. Is there a d3 projection that will put DC at the right angle? ...
1
vote
2answers
66 views

Redefining point shapefiles in MXD that have no projection and are located in different folders using ArcPy?

# Script to use Layers in MXD source file paths to locate and redefine projections import arcpy, glob, os, sys, arcgisscripting from arcpy import env, mapping path = os.getcwd() env.workspace = ...
0
votes
1answer
44 views

Defining Projection Lambert Conformal Conical w custom GCS

I have a shape file from Mexico´s INEGI site that doesn´t have prj file. I am having trouble defining the projection in Arc. INEGI tells me it is projected as Lambert Conformal Conical with a ITRF92 ...
1
vote
1answer
40 views

Define Projections for layers with multiple locations in MXD's

# Script to use Layers in MXD source file paths to locate and redefine projections import arcpy, glob, os, sys, arcgisscripting mxd = arcpy.mapping.MapDocument("N:\MXDs\_ThomaKL\MXD GPS ...
0
votes
1answer
79 views

How to overlay Image to openstreetmap using leaflet.js

I want to overlay a wide range satellite image onto openstreetmap using leaflet.js. The satellite image is in Equidistant Cylindrical Projection. This is how I initiate the layer. ...
5
votes
4answers
8k views

What is the projection of WGS84 in GIS software?

WGS84 is a reference ellipsoid that determines coordinates of every point on Earth using latitude, longitude and height about the its surface. This ellipsoid is often used as a base to make maps. ...
3
votes
2answers
48 views

Alaska Series E projection in ArcGIS for Desktop?

I am trying to digitize a scanned map that appears to be in the Alaska Series E projection. I have also seen this referred to as Modified Transverse Mercator. While this projection is listed as ...
2
votes
4answers
1k views

Can Civil 3D reproject shapefiles? [closed]

Sorry to ask, but I just don't have time for help menus this week. That said, does anyone know if CAD is capable of re-projecting shapefiles? I find myself in a situation whereby I may have to use ...
1
vote
2answers
45 views

Displace Lat/Long by meters

Sorry for the inflammatory title, Yes, I know these cannot be added. Problem: I have a vehicle that is reporting LL84, coordinates. It has a sensor that reports footprints of obstacles (LineString, ...
1
vote
0answers
24 views

Loading AHN files correctly into MicroDEM?

In the netherlands we have the ahn elevation data files(to be found on: http://geodata.nationaalgeoregister.nl/ahn2/atom/ahn2_05m_ruw.xml) (based on rd projection). If i imort these files into ...
4
votes
2answers
797 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
0answers
38 views

Getting same results from Mapping toolbox of MATLAB as ArcMap?

I am newbie in GEO. I have a point [lat,lon] = [-77.5100 , 166.4000]. I want to find its projection based on equidistant Azimuthal projection method. When I use ArcMap 10.3.1 (with default ...
1
vote
1answer
58 views

How to make two layers with different CRS line up correctly?

I have an Excel Table with Lat/Long information. Its lat/long of this coordinate System: UTM zone 29n My population density map instead is this coordinate system: UTM WGS84 Example: Barcleyville: ...
1
vote
1answer
389 views

QGIS Layers Not Lining Up

I am new to QGIS, I have been using ArcGIS for most of my maps. I have two layers that are not overlapping properly. One is a shp file from a GIS clearinghouse and another from a delimited text ...
2
votes
2answers
2k views

Layers with same coordinates not lining up

I have a project where I have a few layers (State of Texas, cities, roads, etc.). They are all resaved and projected to NAD83 / UTM zone 14N EPSG: 26914. The project CRS is also NAD83 / UTM zone 14N ...
0
votes
1answer
61 views

Open Layers 3, GeoJson EPSG:4326

I have two layers: 1) var layer = new ol.layer.Tile({source: new ol.source.OSM()}); 2) var layer_g=new ol.layer.Vector({ projection : 'EPSG:4326', style: new ol.style.Style( { ...
0
votes
0answers
34 views

QGIS Server & custom CRS

I'm using QGIS Server and an OpenLayers-based web client (in EPSG:3857). I have a QGIS project that I want to serve with QGIS Server, containing layers in several CRS, including custom ones. ...
2
votes
1answer
2k views

Transforming regular lat/lon to rotated lat/lon?

I am currently working with climate data projected in a rotated lat/lon grid and came across this excellent 'cookbook' by mkadunc on how to manually transform rotated lat/lon to regular lat/lon: ...
1
vote
1answer
67 views

stack rasters with different extent and resolution in a loop with R package raster

I would like to stack rasters with the R package "raster". Layers are in ascii format. I want to crop them to have the same extent and project them to have the same resolution. My code gives raster ...
0
votes
0answers
12 views

MapInfo2leafletjs tool

I've downloaded a tool to export a table from MapInfo GIS to leafletjs. The base map from Openstreetmap has been created, but the choropleth map of regions is not being displayed. One possible ...