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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49 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 ...
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62 views

OTF reprojection and reprojecting layer not working in QGIS

more troubles in QGIS. I georeferenced this raster in Corrego Alegre UTM23S and loaded up, so project CRS automatically changed to that. So far so good. I need it to be however in WGS84 UTM 23S. None ...
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2answers
33 views

Is publishing geodata in unprojected latlon coordinates better than a local UTM projection?

This is meant as some kind of reference Q&A. Unless I am working with truly global data, I always prefer projected, local, metric coordinates so that calculations like area or distances are ...
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2answers
140 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 ...
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2answers
89 views

Defining the azimuthal equidistant projection of an Environment Canada weather radar map

Environment Canada helpfully provides recent captures of all national weather radar stations at http://dd.meteo.gc.ca/radar/PRECIPET/GIF/ at ten minute intervals. These are the same GIF images as ...
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2answers
90 views

Projection issues whilst opening shapefile in ArcMap created in QGIS

I created a polygon shapefile in QGIS. Projection was saved as EPSG: 3857, WGS 84 / Pseudo Mercator. When I open this shapefile in ArcMap the projection sets itself as WGS_84_World_Mercator which I ...
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36 views

Impossible to define the shapefile projection properly [duplicate]

I downloaded some dataset from Hot Export. By default they don't have any projection or coordinate system defined. The only thing I can see is the Feature Extent with values such as: Max Y ...
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126 views

Projection For Measuring Distances

Is it the case that when I use Arc GIS to compute nearest distance from a point to a poly-line/polygon, I need to project them both in an equidistant projection? Note: I am using the near tool. What ...
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1answer
93 views

After how much distance does the x,y coordinate system become noticeably distorted?

I'm working with maritime sensors that give information of moving objects it detects, in azimuth, range and elevation, and we convert it to x,y coordinates for our application to be able to process ...
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3answers
352 views

How to project a layer from WGS84 lat/long (automatic projection) to WGS 84 UTM Zone 23S in QGIS?

So I have a vector layer of polygons in WGS 84 lat/long (i.e. using the automatic projection for lat/long and WGS84 datum). I want to change that to WGS84 UTM 23S in QGIS. I tried doing like online ...
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1answer
57 views

Polyconic Projection for China?

I have a set of locations/points and I am trying to compute the nearest distance of these points from a Polyline. The points and the polyline lie in China and the Geographic Coordinate System is WGS ...
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1answer
155 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 ...
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20 views

Problem with the DSID Data Set Identification

In my s57 file, I need to set the extent of the mapcanvas, for that i use : mpMapCanvas->setExtent(mpS57->mMapplay.value(DSID)->extent()); but if I display the value of the extents xmin, ...
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1answer
56 views

How to get correct lengths when switching from GCS to PCS?

I'm working on ArcMap 10 and need to get the lenghts (in meters) of the segments composing my line feature class. GCS of the line is WGS_1984. Extent of this data should be: Left 11.236520 dd, Right ...
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1answer
65 views

Is there a difference in results between Simplifying a geometry by different projections?

We have geometries in a PostGIS database projected in srid 4326. We need to have these geometries simplified with ST_SimplifyPreserveTopology. My question is whether this geometry needs to be ...
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1answer
80 views

Strange effect in gdalwarp output

I am using gdalwarp in python to extract and re-project reflectance bands from MODIS level 1B (MOD021km). An example of the command that I am using is the following: gdalwarp -of GTIFF -tps -t_srs ...
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1answer
55 views

Extracting *.tif agricultural area from shapefile?

I am attempting to extract from an image using Esri shapefile that is in the zip file RR_KZKD2012 In ArcGis the spatial reference is Projected Coordinate System: WGS_1984_UTM_Zone_43N. Then am using ...
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97 views

Feature Points Shapefile missing Spatial Reference Information

I'm working with ArcMap 10 and I have a feature points shapefile from the Florence (Italy) municipality open data (http://opendata.comune.fi.it/statistica_territorio/dataset_0040.html). Each point is ...
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1answer
110 views

Postgis geometry column with different srid

I have a table that has geometry column named the_geom. I set SRID value to 29903. And I used Openlayers api to view data on map. I set map srid as 29903 and works well. But if I need to show my data ...
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1answer
96 views

Using CAD data that is not to be projected in ArcMap?

I need to incorporate CAD data into my geodatabase but the usual steps seem to require defining a projection or projecting the data in some way. All of my geodatabase's feature classes are in ...
2
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1answer
240 views

How to access Leaflet EPSG:3857 coordinates?

I read everywhere that Leaflet is internally using a spherical web mercator (EPSG:3857), but whatever I try I get either Lat/Lon (EPSG:4326) or strange coordinates I dont understand: ...
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34 views

NetCDF4 Files: Missing Projection & Varying Dimensions (Multiple Files)

All, I hope you can shed some light on issues I've been having regarding NCEP Reanalysis-I netCDF-4 file format: First issue, Projection information is not stored on the downloads I obtained from ...
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1answer
172 views

Layers with the same CRS in QGIS do not line up

I am busy with a project where I have to layer a .dxf and a .kml file but the layers are not lining up. The .dxf file's coordinates are completely wrong and the scale also does not appear to math up ...
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36 views

Aligning Points in Decimal Degrees

Running ArcMap 10.3 I am displaying a layer of manholes from a table coming from SQL. The XYs are in decimal degrees however they are displaying no where near my other layers (NYC PLUTO). I have ...
2
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1answer
96 views

Working with lidar points (LAS To Multipoint) in ArcGIS for Desktop?

Currently I'm working with the LAS format and want to transform from WGS84 to RSO Kertau Malaysia. I'm using ArcGIS-Las to Multipoint and Data Management Tool-Project and succeeded in the ...
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1answer
352 views

What is/are the coordinate systems used in South Africa?

What are the principal datums and projections used in South Africa including the names of geodetic datums and their projections?
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1answer
61 views

Projected MODIS data not aligning with ESRI basemap in ArcGIS for Desktop?

I can not get 1km MODIS data aligned with ESRI basemaps in ArcGIS 10.2.2 for Desktop. See the photo below. I reprojected MODIS17A3 data using the MRT (MODIS reprojection tool). I selected WGS84 ...
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2answers
229 views

Proper ground-to-grid correction and projection from old survey maps

I asked this question over on the ESRI geonet site, but haven't had any luck there, sorry for the duplication... I'm working on digitizing a group of maps from the 1950's that show locations of ...
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14 views

Vector data getting misaligned in final print in QGIS [duplicate]

My printcomposer view shows the data correctly aligned with background OSM/Google/Bing data but the final print makes it all misaligned. Data is in 3857 What can I do?
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1answer
135 views

GeoJSON and OSM layers with different projection

I have a GeoJSON from NaturalEarth for world state boundaries and I want to display it with only without backgroung. But also, I want to add a OSM layer as another baselayer option. The code I am ...
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53 views

Projections way off on data imported into QGIS?

I have elevation data as a .shp from the USDA ARS and Hi-Res Orthoimages (Mystery Projection (UTM 15N?)) from the USGS website as geoTIFFs (plain NAD 83). I am trying to project all of the images ...
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94 views

Which projection can I use to see alignments on great circles?

I want to put on a QGIS map some historical sites to check if they are aligned. If an alignement exists, the points should stay on a great circle (is this correct?). I want to visually verify this ...
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23 views

Generating Scale Bar for Raster Image Data

My goal is to create a scale bar for a printed map at 1:1,000,000 scale. The input dataset is a Mercator projected geotiff. Using GDAL it is possible to get the spatial reference information and ...
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35 views

Why can I publish a layer in Geoserver using these two different projections?

I have a shapefile with this projection in the .prj file GEOGCS["GCS_WGS_1984", DATUM["D_WGS_1984", SPHEROID["WGS_1984",6378137.0,298.257223563]], PRIMEM["Greenwich",0.0], ...
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42 views

Troubles setting correct projection in SDE

I have to transformate data and change the coordinate system but have troubles to set it correct programmatically. I have: ArcGIS 10.2 / MS SQL-Server 10.0.5520 / sde 10.2.2 My steps: 1) Some ...
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1answer
352 views

What simple and light Java library to use for WGS84 to UTM conversion?

Geotools and Geotoolkit are huge and complicated. CTS (1.3.3 from Maven) failed on me by not even being able to run its own test example (slightly modified ...
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1answer
256 views

Get Radius in epsg 4326 with Openlayers 3

What is the best method for getting the radius of a circle in Openlayers 3 in epsg 4326 (geodesic)? I'm using this example for a base and trying to draw a circle while getting the radius, but using ...
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2answers
27 views

Selecting the correct projection for NAD_1983_HARN_WISCRS_Bayfield_County_Feet

I am trying to map the following projection but having issues finding a one that works. I ahve used http://prj2epsg.org/search which gives a few results but none seem to work that well. ...
0
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1answer
56 views

What would a map of the world look like if lat/longs were treated as projected coordinates? [duplicate]

I'm not quite sure if I'm phrasing this right. It's just occurred to me that lat/longs are two dimensional coordinates like any other projected coordinate system, so it's presumably possible to create ...
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84 views

Equal Area Projection for Indonesia - Standard Parallels

I am trying to do area computation stuff over whole of Indonesia and as such, am using the following projection: http://spatialreference.org/ref/esri/asia-south-albers-equal-area-conic/ To make this ...
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1answer
67 views

What projection to use for many parts of the world

I'm creating a poster which has many separate maps (rivers of the world). I'd like to use a similar projection for each of them, so they're comparable in terms of shape and size. I guess I want some ...
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1answer
92 views

Reproject GEOTIFF tiles from UTM to Plate Caree

I need to reproject several GEOTIFF tiles(each having different height/width) in six different UTM zones from UTM to Plate Carree. Output of gdalinfo of two sample tiles is enclosed. As is clearly ...
0
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1answer
45 views

projection for high accuracy small areas

I need to convert (lat,long,height)points into a cartesian system for an area as small as 40kmx40km or even 10kmx10km. I'm currently using the UTM projection, but there are some issues regarding ...
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1answer
55 views

arcgis 10.2 .shp with no projection info but .xml file

I need help opening a shp file which has no projection info in ArcGIS 10.2 I have .shp , .shx , dbf and .xml file. The .xml file details are below . QUESTION : can i make .proj from below ...
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2answers
81 views

Error when creating data with special characters and numbers [duplicate]

My code will not project and store the feature layer in the scratch.gdb. "ERROR 999999 ... The table name is invalid. The table was not found. [17_5330_51961Lake]" The interpreter doesn't like "-" ...
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72 views

Proper projection name for NAD83 2011 revision

I have two PRJ files, one from ESRI and another from some custom GDAL/OGR code I wrote (pasted below). I was trying to have both work in NAD83 UTM10N with the 2011 revision. The ESRI file has 2011 in ...
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1answer
509 views

Converting Long/Lat into X/Y in the same coordinate system

I have a text file with two fields including Longitude and Latitude in degrees. I need to convert this into two fields that contain these values in X and Y. The source and destination coordinate ...
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29 views

Are there standard math formulas for esoteric map projections (like Dymaxiom)?

I come from graphics programming, I have been mucking about making map apps with more interests in map projections. I have a simple 2D tile map, but I'd like to convert that to some of the more ...
3
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2answers
2k views

Is WGS84 a Coordinate system or projection system? [duplicate]

WGS84 is often referred to as a "projection system" and sometimes it is confusing to me about what a "projection system" is and where WGS84 falls in one. Could someone please clear that up for me?
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11 views

Set of intersection points in trilateration / multilateration [duplicate]

Like in this post I will get a set of points (3 or more) with latitude, longitude and distance (in KM) information to find out the target location. A distance could be about 500 KM. The circles ...