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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198 views

Which training courses in Geodetics can you recommend?

Can anyone recommend any training courses in geodesy which would cover the following objectives: Case studies on coordinate issues Overview of geodetic datums, coordinate reference systems and ...
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275 views

Reprojecting raster data from a rotated pole grid

I have some raster data (ASCII grid files) that use a custom rotated-pole projection, that I'd like to reproject into something more useful, such as lon/lat WGS84. A description of the grid projection ...
1
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2answers
733 views

WFS reprojection problems

In geoserver i have a layer in EPSG:4326. In OpenLayers i add it on map as WFS: markerLayer = new OpenLayers.Layer.Vector('Markers',{ strategies: [new OpenLayers.Strategy.BBOX()], ...
0
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1answer
102 views

Imported GPS data does not overlap with map

I´m working on QGIS and I geocoded 2 addresses of a city in Germany and tried to input the text-file as a layer. It worked, but the 2 points must be in the map of the city and if I zoom to the ...
2
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1answer
97 views

Ok to measure and union a projected-on-the-fly shapefile in ArcMap?

I have a dataframe in arcMap 10.0.4 that is of Africa Albers Equal Area Conic PCS. I bring in a census shapefile of WGS 1984 CS and it is projected on the fly. I do 2 things: I use the calculate ...
2
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1answer
512 views

Transformation of user-defined projected coordinatesystems

I want to transform from one projected coordinate system (pcs) to another using ArcGIS 10. Unfortunatelly the starting system is not predefind by ESRI and thus I´m not sure the software is doing what ...
0
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2answers
128 views

Getting a “square” of lat/lon for database query [duplicate]

So I want to get the square formed by a single point of lat/lons, my plan was to take that point's latitude, divide by 360, and multiply by the circumference of earth. Giving us the distance from the ...
1
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1answer
95 views

Setting coordinate systems in gvSIG: workflow or transformation issues

I am learning how to use gvSIG 1.10 (Mac OS 10.6.8 Snow Leopard). My goal is to create a simple county map of Illinois using the base data shapefiles available from the Illinois Natural Resources ...
5
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3answers
2k views

Using arcpy what is the most efficient way of projecting a selection from a large data set?

I have a large data set X(x1-xn) from which I must select consecutively the attributes A(a1-an) from X.fieldsSRC or X.fieldDST and project the selections. I have a functioning arcpy script that does ...
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0answers
148 views

How to join edge of International Date Line in world file?

I am currently using world file (http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html) for international boundary information. Now I have difficulty with map projection that the map ends with ...
1
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3answers
84 views

Trying to match delimited text layer to my shapefile

I'm pretty new to QGIS and having a bit of trouble getting a text layer to match my shapefile. I'm trying to plot Canadian cities on a shapefile I have of Canada provinces. The provinces shapefile is ...
3
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2answers
3k views

Get Lon Lat values from a GEOGRAPHY data type in PostGIS

After storing lon lat values as a GEOGRAPHY data type, how do I retrieve the individual lat lon values? Failed attempt: SELECT id, geog, ST_X(geog), ST_Y(geog) FROM locations; Error: No function ...
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0answers
38 views

Determining the SRID of a dataset in PostGIS [duplicate]

Sometimes the dataset provides some information about its projection. For example, it can mention Horizontal_Datum_Name: North American Datum of 1983, Ellipsoid_Name: GRS1980, ...
2
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2answers
2k views

What Spatial Reference System do I store Google Map's Lat/Lng in

I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and Openstreetmap and its services like the Geocoder/Nominatim. I'm ...
2
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2answers
461 views

What's the correct transformation for Lambert Conformal Conic for Wyoming?

I am a newb in QGIS. I have loaded QGIS 1.8 (Lisboa) and practicing with a number of maps for portions of the state of Wyoming. My maps are mostly in UTM 12N NAD 27 & NAD 83 some are in decimal ...
4
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1answer
326 views

What's the difference between Geographic coordinate system 4019 and 4121?

I have a DEM with cell size 100,100 with geographic coordinate system GRS_1980_Transverse_Mercator, Datum: D_GRS_1980. I created some extra shapefiles with projected coordinate system: Greek_grid, ...
2
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1answer
513 views

Correct coordinate systems, but trustworthy distance between points?

I have limited GIS experience with projections and I have some questions about trying to accurately display point data from two different sources in ArcGIS 10.1 in order to do a proximity analysis. ...
3
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0answers
52 views

Projection string for GOES-WEST

Full-res, full-disk GOES-WEST images are available from goes.gsfc.nasa.gov. Is it possible to rig up a projection string for these images? We know the center pixel is at (0N, 135W) and the satellite ...
7
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3answers
9k views

How can I get the proj4 string or EPSG code from a shapefile .prj file? [duplicate]

I have to work with a shapefile defined in an unusual projection, which my GIS software does not know about. How can I get the proj4 definition or the EPSG code for the projection?
2
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2answers
2k views

Layers with same coordinates not lining up [QGIS]

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 ...
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0answers
96 views

How to import multiple shapefiles each with different source projections to postgis

I have a couple thousand .zip files each with a .shp, .dbf, .shx, and .prj inside them that I want to load into postgis. The problem is, they have many different source projections (each defined in ...
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2answers
66 views

problem about reprojection

I am a new GIS user, I have some problem can not be solved by myself. I get a shape file generated from an Excel file. at first, my projection is WGS_1984_UTM_Zone_48N some data are inside my country ...
3
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1answer
162 views

How to bulk import ESRI projections into Postgis

Where can I get a file that would allow me to bulk upload all of the ESRI projections into the spatial_ref_sys table of postgis. I know that you can get insert statements on spatialreference.org; ...
2
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1answer
352 views

Which BC Albers should I use and is there any difference?

I was about to calculate the area of some polygons and before I did I did some research. I found that the area of the polygon will be represented in the units of the projection used. So I did some ...
0
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1answer
253 views

constant deviation projecting lat lon to itm(israel tranverse mercator

i use two different ways to project lat lon data taken from google earth to ITM (Israel Transverse Mercator) and export the data to arcmap same ways i try to unproject ITM data and export the data to ...
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1answer
144 views

Projection WGS 84 is slightly displaced referring to a hillshade in QGIS

I have a hillshade and a vector layer. The vector layer is slightly displaced referring the hillshade. About lat=100m and long=175m The CRS of the project is EPSG:3397 - PD/83 / Gauss-Kruger zone 4. ...
4
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2answers
1k views

Cartesian world sized projection WKT/EPSG code?

I am after the EPSG code or Well Known Text (WKT) of a projection that puts the centre of the earth a 0,0,0 and each point is a cartesian XYZ distance from that. My existing data is in WGS84 ...
6
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1answer
119 views

Should I Reproject Data Which Has Been Captured Incorrectly?

I'm working on a project for a client which is migrating data from an Oracle database to an ESRI Geodatabase. When data for this project was initially captured over 15 years ago, the coordinate ...
0
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0answers
69 views

export WebMap in a different projection than the WebApi

I am quite new to the Flex WebApi world. I am using the Flex WebApi and have set up map templates to print maps out to my own template as a PDF. In my template I have the Map grid set. When I eport ...
3
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1answer
150 views

CRS Austrian Lambert/WGS84

I am totally new to Qgis (or GIS in total): My problem is to get two layers in same CRS to do an intersection and further analysis described in the blog of underdark (Groupstat tutorial). My is the ...
0
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1answer
2k views

Conversion from N,E to Lat/Long And Lat/Long to N,E will always be same? [closed]

I have an excel tool for the conversion of following lat/long: Lat: 23° 11’ 24.67503’’ S Long: 118° 46’ 6.15742’’ E , which gives me following N,E: Northing: 7,434,317.43 Easting: 680,991.69 But I ...
2
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0answers
181 views

Proj4 inconsistent longitude after projection

All coordinates expressed in this question are (longitude, latitude), the default for proj4. London is at (-0.1460838, 51.5170986), and San Francisco is at (-122.419302, 37.775549). According to the ...
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0answers
73 views

Projection for Tracking a Vehicle

I'm looking for the best coordinate system projection to use for cartesian calculations while a vehicle is running from its starting location to about 100 miles from that spot. The offline format ...
3
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1answer
294 views

Why are two incompatible projections used together in OpenLayers? [duplicate]

While going through the examples in OpenLayers, I notice several examples with the following code: map = new OpenLayers.Map('map_element',{ ... units: 'm', projection: new ...
4
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1answer
252 views

Error in Min. Bounding Geometry results

I'm getting consistent, weird results from using Minimum Bounding Geometry to make circle polygons. I'm not sure if a datum issue, but I'm leaning more towards something wrong with Minimum Bounding ...
3
votes
3answers
362 views

How to reproject to other projections than WGS84 or Webmercator?

I have an OpenLayers map with a vector layer to add points on. I'm using Google Maps as the base layer. After the point is added, I need to store the data in my database as lat/long and x/y. Can I ...
7
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5answers
9k views

OpenLayers: ALL image layers are out of place on google maps v3 and OSM base layers

Summary: I have 2 different image layers that looked fine with my old mapstraction/google maps based system. Using the same coordinates as bounds in openlayers results in a shift to the north by like ...
4
votes
2answers
538 views

Setting coordinate systems in gvSIG: Is the workflow similar to QGIS?

I am still learning how to use coordinate systems and projections, but I hope this basic question will be easy to answer. My goal is to be able to use either QGIS or gvSIG to create a simple county ...
4
votes
1answer
160 views

Global projection with zero scale distortion at non-zero latitude

I am looking for a global projection with zero scale distortion at non-zero latitude. I have tried using an Oblique Mercator projection centred at a specific latitude and longitude of centre (with ...
2
votes
1answer
105 views

QGIS mixing up CRS

I´ve just started working with QuantumGIS for my thesis. I ordered shapefiles with the CRS: ETRS 89 UTM Zone 33N, but QGis layer properties now shows the layer has a different CRS (namely SWERE99 TM) ...
3
votes
1answer
221 views

how can I know which projection has this data?

I have data in an unknown projection to me. I open it in QGIS and I see that the shapes are ok, but I need to identify the projection in order to merge this data with other stuff. The points look ...
11
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1answer
916 views

Great-circle lines in Equirectangular projection

Just to check that I'm on the right track: Are all great-circles on the sphere and in equirectangular projection (i.e. latitude, longitude pairs) either: meridians (i.e. going pole to pole) of the ...
0
votes
1answer
356 views

How to get DXF to show up in the right spot?

I just followed the advice of this forum post in order to export the vector layers of a PDF for usage in ArcMap. The map vector layers in the PDF were spatially referenced. I was able to export the ...
5
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1answer
254 views

Having trouble finding out what coordinate system a map is using, and how to convert it

I'm using Small Area shapefiles in Ireland from the Central Statistics Office (CSO) website. The link to these is here http://census.cso.ie/censusasp/saps/boundaries/ED_SA%20Disclaimer1.htm (Look for ...
3
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0answers
521 views

VBA Convert decimal degree to Meters button

I have 2 data frames one which has WGS data in it and the other OSGB1936. I am trying to create a button where the user can input decimal degrees (WGS) and it will zoom them to that location in ...
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139 views

What is a radar projection?

Trying to overlay a radar image(radar projection) on a mercator projected map, but have no idea about what a radar projection is. So here are my quesions: What is a radar projection? What's its ...
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0answers
262 views

What is UTM Zone 0?

I am currently working with some roadway link data and it is being projected in UTM. After importing the shapefile into GRASS I can view the map and it looks correct but when I view the projection ...
1
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1answer
612 views

What are Bands, Dimensions, and Histograms in QGIS?

First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct? If so then bands play the role of color mixing and masking. Are there any other ...
4
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3answers
3k views

Parameters for ED50 -> ETRS89/WGS84 seven-parameter transformation which are good for Denmark?

I am looking for parameters for a seven-parameter transformation (Rx, Ry, Rz, Tx, Ty, Tz, s) from ED50 UTM (zone 32U) to ETRS89 and/or WGS84. The best match I could find is here: ...
1
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1answer
220 views

Why are the areas covered by 2 Universal Polar Stereographic (UPS) coordinate different?

According to http://en.wikipedia.org/wiki/Universal_Polar_Stereographic_coordinate_system. the area covering Arctic is less than Antarctic. Any reasons for it? It is due to the shape of the lands?