Aligning geographic data to a known coordinate system so it can be viewed, queried, and analyzed with other geographic data.

learn more… | top users | synonyms (2)

10
votes
7answers
8k views

How to georeference a vector layer with control points?

I have a non-georeferenced vector layer that I need to be georeferenced. With raster layers the task is easy and straightforward, but I have no idea what should I do with my vector layer. I have a few ...
5
votes
7answers
6k views

How to georeference a dxf?

I have got myself a dxf which is built with units in the wrong scale. How do I upscale that in QGIS? Note it does open in QGIS, just in the wrong map units and location.
12
votes
4answers
7k views

Adding PDF (especially GeoPDF) to ArcMap as data?

I receive a lot of PDF maps (vector, image, with georeference and without) and I am having to convert them to an image file before I can add them to ArcMap and georeference. I can't see any obvious ...
5
votes
2answers
897 views

QGIS affine - form of equation

I am at the mercy of a govt authority who have provided utility information in a cad format with a 0,0 origin and a nonsense grid. About a dozen files, the grid and origin are entirely arbitrary. To ...
1
vote
2answers
4k views

I want to georeference jpg map without any digitizing data?

I have only a jpg map but dont have any digital data for georeferencing that jpg.So is there any way for georeferencing my map (like googlemaps)?
16
votes
1answer
1k views

Are there any general rules of thumb for selecting a transformation for Georeferencing?

There are several transformations that can be used when georeferencing a raster: 1st order Polynomial (affine) 2nd order Polynomial 3rd order Polynomial Spline... etc Are there any specific rules ...
9
votes
3answers
4k views

How can I transform a georeferenced JPG to a georeferenced TIF?

I have an georeferenced JPG file and a JGW file containing the coordinates. How can I transform it to a georeferenced TIF file and a TFW file? I have tried to save the JPG file as an TIF file in ...
4
votes
2answers
649 views

Georeference vector linework

I'm new to GIS and a lot of searching didn't answer my specific question so far, so I hope someone can help me here. What I want to do is creating a small web application to visualize election ...
5
votes
3answers
2k views

Convert an arbitrary meta-data-free map image into QGIS project

My background: experienced programmer, amateur historian, complete beginner to GIS (so I'm using QGIS). I did learn to use the QGIS georeferencer tool though. The input: suppose I have an image like ...
0
votes
3answers
361 views

Georeferencing window won't open QGIS 2.4

I had the georeferencer window open in QGIS 2.4 while project was running, I accidentally closed the Qgs document with the georeferencing window open (worked absolutely fine till then). When I opened ...
27
votes
7answers
3k views

Work flow for georeferencing imagery using open source tools?

Does anyone have a recommendation for a work flow for georeferencing high resolution aerial photography using open source tools? Comparison of user friendliness and robustness between Quantum GIS ...
5
votes
2answers
1k views

How do I specify a CRS for a fictional game map in QGIS?

I am about to start playing a steampunk RPG game called The Iron Realm, which uses a fictional world map. I have recently started using QGIS v1.7 and have no real experience with GIS sysstems. I have ...
13
votes
3answers
10k views

Is it possible to georeference an existing, un-georeferenced pdf?

I was wondering if there was anyway to georeference a pdf directly without first converting it to an image. I have access to ArcGIS 10.1 but haven't been able to find any information that would ...
10
votes
2answers
1k views

How can I improve my Georeferencing results?

Background This is my second question related to georeferencing naked raster maps in order to re-visualize them on different coordinate systems and in conjunction with other data layers. The previous ...
5
votes
2answers
13k views

Coordinate system and projection for georeferencing Google Maps image in ArcGIS Desktop?

I have saved Google Maps image (not Google Earth) of area at latlon(17.692437,83.218689) by some method in jpeg format. It is an exact snapshot of the Google Maps. Now I need to geo-reference it to ...
12
votes
4answers
8k views

What is the difference between geocoding and georeferencing?

After some googling around both seem to be interchangable words, where we speak of tying the spatial info of a real place and storing in database. But still I am not satisfied, there should be some ...
5
votes
1answer
358 views

Unknown Coordinate System on old drawing

I work with many old civil engineering documents, and occasionally I'll need to georeference one which has coordinates pairs listed at many given points but does not list which coordinate system these ...
3
votes
5answers
3k views

How to find coordinates for a lot of locations based on the town or village name?

I have got an Excel spreadsheet with roundabout 15,000 locations, which are only identified by the towns or villages name and the country. I am intending to present these on a world map. Therefore, I ...
7
votes
1answer
958 views

Batch Georeferencing in ArcMap 10.2

I have about 50 pdf maps that I would like to batch georeference and/or georectify. I've saved one as a jpg and georeferenced it manually and would like to automate the rest which are in the same ...
5
votes
5answers
12k views

Trouble when georeferencing CAD files in ArcMap

I've definitely got at least a couple of grey hairs while trying to convert some dwg. files to shapefiles. I've seen that this subject has been disscused a lot, but hope someone will have the ...
2
votes
1answer
123 views

Georeferencing Image using saved Link Table from another Image?

I had a scanned map that I did did a georeferenced a few weeks ago and saved the link table. Now I have two more scanned map that need to do the same thing. It is the same area and one of them I did ...
2
votes
2answers
233 views

Problem with reprojecting raster from MGI 6 to WGS

When I reproject a raster from Mgi 6 to WGS 84 using Warp in Quantum gis it makes mistake ( about 380m). Is there any way to avoid this?
1
vote
1answer
904 views

GeoReference tiff image into the Google map?

I want to Geo-reference a tiff image contain a Map for a specific region, I need to add this region(image) and Geo-reference it on the Google map, SO I can see on the map for the region I select the ...
9
votes
1answer
11k views

Georeferencing shapefile using ArcGIS for Desktop?

I have a shapefile with some polygons that I would like to superimpose to a raster image, but unfortunately they don't match perfectly due to the reference system the shp has been created with. So, I ...
5
votes
2answers
5k views

Convert x, y position in georeferenced image (with world file) to longitude, latitude?

What steps do I need to do in order to calculate longitude and latitude for a specific pixel in a georeferenced image? For example this image ...
1
vote
1answer
309 views

Add georeferenced png layer to map automatically

Using ArcGIS Desktop v10.2 with an Advanced level license we have georeferenced our engineering drawings in PNG format. Next we have created a polygon layer for every single drawing to see the Area of ...
0
votes
2answers
178 views

Geo- referencing Projected coordinated raster with GCS - ArcGIS

I have raster displaying Lat/ Long grid, but map information shows that, it s been mapped in Gauss Krugger projetion/ Beijing 1954. So, technically we need to geo reference the map in Gauss Krugger/ ...
8
votes
3answers
10k views

Generally accepted root mean square (RMS) error for rectifying topographic maps

This is a generic inquiry on the common practice/standard for determining the acceptable values of RMS when georeferencing topographic maps. Is there an absolute value? Some literature suggests that ...
6
votes
3answers
2k views

30,000 data points… can this be reasonably served using openlayers?

I'm trying to tackle a web GIS problem and need to figure out the best strategy. I have a map with 30,000 cells on it forming a grid for the province of Alberta. I have a list of data points for ...
7
votes
2answers
4k views

How to generate world files for raster X?

Given a list of georeferenced rasters, about a hundred, what is the simplest method to generate world files for each? In this case the source rasters are either geotiff with embedded georeferencing ...
3
votes
2answers
1k views

Georeferenced 3D Model Import

How can we open a 3D MAX File(3D Building model with exterior and interior elements)in Autodesk Infrastructure/LandXplorer or ESRI CityEngine? How can we georeference a 3D vector building model?
2
votes
1answer
287 views

How to keep georeferencing from ArcGIS when importing raster into QGIS?

I tried searching for the answer to this, but I didn't see anything, so here it goes: I have previously georeferenced some .png raster images in ArcGIS 10.2.2, and could like to import them into ...
10
votes
1answer
883 views

What is some theory on the number of GCP when georeferencing?

Just wondering, is it always better to have more than 3 GCPs? Should the GCPs be spread out evenly? Where can I find some general resources on the theory of this? Other than trial an error, which ...
6
votes
3answers
22k views

Steps to creating a GeoTIFF

First off, I'd like to mention that I'm pretty new to working with GIS, so please forgive my inexperience. My situation is as follows: I'm tasked with georectifying a set of imagery and importing ...
6
votes
5answers
1k views

Georeferencing aerial photos when only centroid is known using ArcGIS for Desktop or ERDAS Imagine?

I have heaps of aerial photos that need to be georeferenced. I have access to ArcMap and ERDAS. All I am given is an excel sheet with the centroid coordinates of each image. Each photo covers ...
5
votes
1answer
358 views

How do I georeference a ski map?

I have a map of a mountainous landscape, http://skimap.org/data/989/60/1218033025.jpg. It contains a number of known points, the lat-longs of which can be easily found out using google maps. I wish ...
5
votes
4answers
2k views

How to generate a world file with rotation

I`m writing code to geo reference some images that I get with a rc plane. I have the central coordinate of the image because its atached to the center of the plane. But I have problems when I open the ...
4
votes
1answer
700 views

Extract coordinates for series of georeferenced files in ArcGIS 10?

I have a series of 1900 spatially continuous images that are georeferenced. Each image is a tif file paired with a tfw file. These images are easily open and shown in ArcMap 10. However, I need a way ...
7
votes
2answers
774 views

How to Georeference Photos With No Spatial Reference?

I have about 100-200 field ground shot photos I would like to overlay in ArcGIS 10 that have no spatial information which I need to somehow develop using a photogrammetric formula. The camera was ...
3
votes
3answers
808 views

DXF to georeferenced SHP

I know how to set projection and georeference bounds of scanned TIFF file, by using gdal, but I don't know how to do the same for vector file. For example I georeferenced TIFF file by using this ...
2
votes
1answer
185 views

How to exactly georeference in QGIS

When I georeference a raster image in QGIS, it's always a bit displaced as in the attached image (the cyan polygon is the template, the red border is the georeferenced image), although I try to set ...
2
votes
1answer
294 views

Geoserver: Georectification via SLD fails

Situation I have a raster image and the coordinates of its four corner pixels. My goal is to warp the image with respect to this coordinates ("georectify") on the fly when requested via GeoServer to ...
1
vote
1answer
468 views

using GDAL/python to stack georeferenced images of different sizes

I am in the process of porting a code I wrote in IDL (interactive data language) to python but am running into a bit of a problem that I am hoping someone can help me with. The code goes like this: ...
1
vote
2answers
2k views

OGR DXF to KML conversion

I'm trying to convert a DXF 2010 file to KML using ogr2ogr: ogr2ogr -f "KML" outfile.kml infile.dxf In the file, $INSUNITS is 6, that's meters, if I'm correct? The problem is that DXF is not ...
4
votes
1answer
398 views

Historical U.S.G.S. Georeferencing

I have downloaded a historical USGS map that is suppose to be a geoPDF. My understanding is that QGIS cannot directly read geoPDF's. I have not had any luck in converting it to a geoTIF in order to ...
4
votes
0answers
496 views

How to digitize directional drilholes from scanned vertical sections? [duplicate]

I need an advice how to do this. Normally, I either receive a file containing drill holes or at least data with xy position, direction, depths and attributes. I then use this data for further ...
3
votes
2answers
171 views

Geographically georeference image with limited information

It is possible to semi-accurately georeference an image given only the following information? I'd like to do this programmatically. Center point of terrain, Lat/Lng (WGS84) Pitch of camera FOV ...
3
votes
2answers
286 views

Layer not aligning after georeferencing using BC Albers

I'm currently having trouble with the georeferencer... after what appears to be successful georeferencing, the map image layer does not align to the vector data. I'm trying to use BC Albers ...
3
votes
1answer
1k views

Why can't I download the georeferencing plugin for QGIS 1.7.4?

I used the georeferencing plugin with QGIS 1.6 and now that I've upgraded to 1.7.4 I'd like to do it again. But when I search for the georeferencer plugin, it's not available! Am I doing something ...
2
votes
1answer
60 views

Georeferencing uneven/irregularly gridded rasters

I'm trying to take a set of NetCDFs and turn them into georeferenced datasets using GDAL. However, the only Geospatial data is a set of 2-D lat/lon arrays. The projection type is not lat/lon. THe ...