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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26 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 ...
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1answer
47 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 ...
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1answer
33 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 ...
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1answer
41 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 ...
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1answer
35 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) ...
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25 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 ...
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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 ...
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3answers
50 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 ...
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2answers
27 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 ...
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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). ...
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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 ...
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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 ...
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30 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 ...
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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 ...
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5answers
178 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 ...
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1answer
34 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 ...
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2answers
45 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 ...
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2answers
200 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 ...
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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 ...
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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 ...
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1answer
52 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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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1answer
26 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
21 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
57 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
40 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
57 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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35 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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1answer
42 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 ...
2
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1answer
65 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 ...
2
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3answers
116 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
31 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
142 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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0answers
8 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
40 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 ...
5
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1answer
57 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
70 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 ...
1
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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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0answers
54 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
54 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
57 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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0answers
43 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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0answers
24 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 ...
1
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1answer
70 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 ...
2
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0answers
32 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
58 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 ...