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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41 views

Define a projection for one point

I'm new to ArcGIS and am using ArcMap 10.1. I wanted to find the distance from a point (lat 36N long 12E) to all the polygons in my shape file. People on this forum helped me out and said that I ...
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49 views

Kartograph - “projection not named”

The Kartograph package looks very promising, so I have been trying play around with it. As it turns out, I have been able to get the most basic map to work (the "world.json" example), but I could not ...
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1answer
59 views

How do I set the projection and coordinate system for a TIFF file?

I have a topographic map of California (obtained from CAL-Atlas) as a TIFF file. I tried importing it into QGis, but it displays the map using a pixel based coordinate system rather than ...
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1answer
110 views

Which projection is being used in this figure?

I would like to use the projection being used in this figure. Does anyone know which one it is? Esp helpful if it is available in ArcGIS. From plant stress page thanks!
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1answer
41 views

Lambert Conformal Conic Projection Inverse Transform after Fitting Ellipse to Noisy LLA Data

I'm using Python and Basemaps to convert some Lat Lon data to the LCC projection and back again. Since it is noisy data representing the footprint of a satellite, I am filtering it and fitting an ...
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1answer
37 views

QGis points distance from shore in metres

I have a grid of depth points in the Irish Sea that i'm trying to add other data fields to, in this case distance from shore. I've tried both of these suggestions to no avail, but am having some ...
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1answer
100 views

In Ogr2OGR: what is SRS?

I am trying to understand this command: ogr2ogr -f "MapInfo File" original.tab wgs84.shp -s_srs EPSG:27700 -t_srs EPSG:4326 I don't understand the s_srs and t_srs paramaters. The help file says ...
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2answers
164 views

How to convert a NetCDF file to GeoTIFF using GDAL

I have a NetCDF file which contains data for the number of rain days in the UK. I'd like to convert it to a GeoTIFF, but can't get GDAL correctly georeference it. See dumps from gdalinfo below. I ...
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1answer
39 views

does Pseudo Mercator Projection causes problem while clipping rasters

I tryed to clip a Raster file using an ESRI shapefile using gdalwarp command, but i always get an empty output file or a wrong clip with wrong location. this the command bellow: gdalwarp -dstnodata ...
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28 views

How can I obtain the unit of a projection SRID?

Given a projection SRID, is there a way I can obtain the coordinates unit string (meter, degree, ...) ? In PostGIS for example, it looks like it is present in the srtext column of spatial_ref_sys. ...
2
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1answer
71 views

Shapefiles from Nationalgrid without a .prj file - what projection are they in?

Im working with these shapefiles: http://www2.nationalgrid.com/uk/services/land-and-development/planning-authority/shape-files/ They show pipelines & electricity grid of the UK. They do not ...
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38 views

QGIS: Albers projection in lat lng?

I'm trying to make a map of Russia in the Albers projection. My projection string is: +proj=aea +lat_1=45 +lat_2=70 +lat_0=40 +lon_0=100 +x_0=20 +y_0=20 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m ...
7
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1answer
171 views

Can I just swap out a .prj file to reproject a shape file?

I'm an experienced software developer -- but a GIS noob. I have a shape file that I am trying to turn into a SVG map with Kartograph. When I try to run Kartograph I get this error: ERROR 6: No ...
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1answer
86 views

Projection problem with ESRI JSAPI and ArcGIS map service

I was trying to obtain a gpx file with some coordinates by drawing on an Openlayers map with an ArcGIS baseMap. When I draw the polyline and create the gpx, if I open it on Google Earth, what I see ...
2
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0answers
14 views

Eliminating/minimizing distortion in 200 NM EEZ buffers [duplicate]

I frequently need to calculate buffers of 200 nautical miles from country or baseline polygons in order to map maritime Exclusive Economic Zones (EEZs). However, I've noticed that when generating the ...
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1answer
68 views

Add EPSG:3857 geometries to map using Leaflet

Right now Leaflet can only add geometries with latitude and longitude values onto the map. If we have a EPSG:3857 point, whose x=-11819829 and y=4200860, how can I add it onto the map? If this point ...
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0answers
15 views

How to Create Consistent Grids using different Projections [duplicate]

I would like to be able to create highly accurate and consistent grids to be used in my simulations. I will need to create 200m2 grids for the UK. The processing software will need data in Lambert ...
2
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2answers
82 views

Problems with transformations in ArcMap

I have files projected in British National Grid. After I have transformed them into WGS_1984. I noticed that if I were to transform them back to BNG the original would not match the new. Is there a ...
2
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2answers
54 views

Measure areas, lenghts in specific regions (Australia, Sout East Asia)

I'm in need to find a suitable projections to measure correctly areas and lenghts for 2 areas of interest. I want to measure both factors for: 1) First region Australia & New Zealand (1st ...
2
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1answer
55 views

How can I transform Real-time Local position system coordinates into GPS/WGS84?

I have a local coordinate system built with Ubisense sensors and tags (it is a real-time locating system used to automatically identify and track the location of objects or people). The local ...
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0answers
22 views

alignment of shapefiles in GRASS

I have two shapefiles below. One is in the state plane projection, and the other is not projected. In ArcMap the shapefiles line up perfectly. When I import them to my mapset (using the override ...
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0answers
99 views

Mercator bias plot in Leaflet

I was inspired by this wikipedia image from the mercator projections page to hack around with leaflet. The idea was to interactively have your cursor move a continent and that it would be corrected ...
6
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3answers
174 views

How can I obtain the same area values provided by the Census for TIGER boundaries using PostGIS functions?

In PostGIS, how can I compute the area of Census Boundaries and obtain the same results as are provided by the Census? For example, most Census Boundaries include attributes for Land Area and Water ...
4
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1answer
118 views

Why is tiff different in epsg 3857 and epsg 900913 in gdal

When I transform tiff from 4326 to 3857 and from 4326 to 900913 in gdal, I get different result(when display in Qgis) eventhough these two projections(3857 and 900913) should be the same. What is ...
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1answer
56 views

Field Calculator returning incorrect length and area values when QGIS project is reopened

Similar to Field Calculator returning incorrect length and area values, but as always slightly different. I have QGIS 2.0 and when I create a polyline shapefile, the field calculator returns the ...
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1answer
31 views

Is it due to irregularity of geoid, we cannot convert the height between spherical datum and local datum by cs2cs?

Is it due to irregularity of geoid, we cannot convert the height between spherical datum and local datum (which uses locally defined geoid and height) by cs2cs? What I mean is that, by using cs2cs, ...
3
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1answer
61 views

How to select projection

I have to compare geometries anywhere in the world; mainly between 65N and 40S but also in the Arctic latitudes. I need "commercial accuracy" - not military or navigational. For example does a line ...
2
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1answer
79 views

Identifying coordinate system for Jersey

I'm trying to plot some X,Y coordinates which should be located on Jersey (the British dependency, not the state). The metadata that came with the points is as follows: Coordinate System: ...
7
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1answer
117 views

Using customized Coordinate System for Archaeological site data

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...
3
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1answer
80 views

Convert planar distance to ellipsoid (real) distance

I have the following linestring which approximately marks an airport runway: LINESTRING(-381578.819887 6574044.360475, -378513.534443 6574799.475787) # EPSG 3857 LINESTRING(-3.427781 50.732117, ...
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1answer
74 views

Change coordinate system using SQL or Javascript

Is there any built in function in SQL Server 2008 R2 which can transform the cordinates from 102100 to 4269 coordinate system something equivalent to ST_Transform from postgres. If there is algorithm ...
2
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2answers
63 views

How do I set a CRS when it isn't listed in QGIS? (Mac, not PC)

I want to work with a shapefile that is in a Coordinate System that I can't locate in QGIS for Mac. When I load this shapefile data, it shows up fine, on-the-fly has generated the CRS data most likely ...
2
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1answer
48 views

using PostGIS to calculate distance of a route over a large area

I'm new to PostGIS and looking to measure the distance of the Pacific Crest Trail which spans western North America from Canada to Mexico. I have a data set containing the lat lon and dates from GPX ...
2
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1answer
62 views

How can I get the ellipsoidal values for length and area using spatialite?

I have spatialite geometry data stored in a spatialite database in WGS 84 (EPSG 4328) format: SELECT Srid(geometry) FROM shape_layer; > 4326 When geometry is being returned as text, it is ...
4
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2answers
74 views

Why is it not advisable to perform spatial analysis on layers with source datasets having same datum but different projections?

I have read that it is not advisable to perform spatial analysis on two layers with source datasets having the same datum but different projections loaded in ArcMap. Since the second layer should ...
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1answer
85 views

Aligning layers with questionable metadata in SW Ontario

After making my best efforts to read/try everything I can on this forum and elsewhere, I unfortunately have to contribute to the wide literature of "my layers aren't aligning" questions. I am working ...
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1answer
151 views

Pseudo-Mercator projection with Decimal Degrees?

Hope this isn't a duplicate, did some searching but none seemed quite the same. Projection I want: WGS84/Pseudo-mercator. Selected. Looks Great. Canvas units I want: Decimal Degress. Selected. ...
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1answer
57 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 ...
0
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1answer
35 views

how to correct merge rasters with different projections? [closed]

how to merge rasters with different projections with correct transforn? For example EPSG:32636 and EPSG:32637 if i do it with gdal_retile command, i have correct view for EPSG:32637 rasters and ...
0
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1answer
52 views

Transformation data austria - slovenia

can anyone please help with fitting together these 2 shape-files? many many thanx https://www.dropbox.com/s/saa9yp7ecg1qxh1/Grenzen.rar
2
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3answers
190 views

How to calculate Polyline length in kilometres without changing projection from WGS84 (using ArcObjects)?

I have Road (polyline) feature class and I wish to find those roads whose length are greater than 500 kilometre. The feature class projection is in GCS_WGS_1984 and I do not want to change the ...
1
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1answer
149 views

get data from WFS and present in using d3js - correct projection

I'm trying to get data for map of Poland. I found WFS service that provides GML files. It is located under: http://sdi.geoportal.gov.pl/wfs_prg/wfservice.aspx?request=getCapabilities&service=wfs ...
2
votes
1answer
67 views

Axis of rendered shape files not showing numbers that are latitude and longitude

I am using rgdal to render some shape file. The first is a set of building zones from NYC Open Data. The second is the NYC coast line from OSM. The Zone files seems to generally render an X axis ...
6
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1answer
97 views

How do I change an existing srs in QGis?

I am showing postgis data with srid 28992 (Amersfoort / RD New). But when I plot the geospatial data on a map (with openlayers plugin), the data is shown a hunderd meters off because the datum shift ...
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0answers
84 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
3
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2answers
99 views

Convert data to another Coordinate Reference System

Assuming I've a point like this : POINT (751318 9760879) This point is in EPSG:27700 coordinate reference system. How do I convert the point to display in a map with EPSG3857 coordinate ...
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1answer
105 views

How to project geographic coordinates to cartesian with the least possible error? [closed]

I need to convert geographic coordinates (in decimal degrees) to cartesian with the least possible error? I searched a lot on the internet but it seems that the conversion is not exact. Could you ...
0
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0answers
58 views

Lambert conformal conic projection - Europa

I am trying to calculate map of Europa in Lambert projection. I am using formula from wikipedia (Lambert wiki), but calculation is verřy slow with comparison to Mercator. I know, there are sin, cos, ...
1
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2answers
600 views

how to convert latitude, longitude projection from epsg:3857 to epsg:4326

I want to use geocode in our application. so that, I got Google geocoding API and could achieve with Google Maps. Problem is that I wanted to achieve the same with my own map which is having ...
3
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1answer
122 views

QGIS not interpreting Lambert Conformal Conic projection correctly

I'm a fairly new user of QGIS and I've run into an issue that I can't seem to solve on my own. I'm trying to work with the NRCan Atlas of Canada Waterbodies SHP file but I'm having an issues ...