Questions tagged [georeferencing]

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

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38
votes
5answers
32k views

How to determine if a tiff is georeferenced or not?

I received a tiff file from someone, but I'm not sure if it's georeferenced. Is there an easy way to check this?
33
votes
7answers
4k 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 ...
27
votes
8answers
30k views

Georeferencing vector layer with control points using QGIS?

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 ...
22
votes
1answer
4k 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 or ...
21
votes
5answers
26k 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 ...
18
votes
5answers
20k 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 ...
16
votes
1answer
9k views

Georeferencing using GDAL?

I have a .tiff image that I am trying to overlay in google earth. For that I require to georeference it first. The image projection is UTM with NAD83 as datum. I know the lat/long of the four corners ...
16
votes
2answers
1k views

How to reverse-georeference with QGIS?

I have a map with a "strange" projection (it's basically hand-painted, not an exact one). I can easily georeference it in QGIS using the Georeferencer plugin and the Thin Plate Spline transformation ...
15
votes
4answers
31k 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 ...
15
votes
7answers
4k views

Best method to georeference oblique photographs?

I have a series of oblique photos taken from an airplane of oyster beds that need to be mapped. Does anyone have any tips on georeferencing oblique images? I have access to ArcGIS and ENVI.
15
votes
3answers
1k views

Which CRS would you use to georeference historical world maps?

Which CRS would you recommend to georeference historical world maps like the ones in the London Geographical Institute - The Peoples Atlas - 1920, e.g. The map displays a lat/lon grid which I would ...
15
votes
3answers
56k 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 ...
14
votes
7answers
18k views

Georeferencing DXF using QGIS?

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.
14
votes
1answer
11k views

Is there an explanation of Root-Mean-Square-Error (RMSE) for Dummies available?

Having an all-round expertise in GIS is sometimes not enough to fully understand some concepts of GIS Science. To add to this, I am also not a mathematician. Considering this, would anyone be able ...
14
votes
2answers
2k views

Improving Georeferencing results? [closed]

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 ...
13
votes
6answers
7k views

Georeferencing in QGIS 3.0?

I just upgraded to QGIS 3.0 (OS X as well on Windows 10) and can not find out how to do some georeferencing. I am told by the software, that GDAL georeferencing is still installed and that I could not ...
12
votes
3answers
26k 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 ...
12
votes
2answers
7k views

Georeferencing vector PDF/SVG/DXF linework using QGIS?

I want to create a small web application to visualize election results on a per poll site basis for my city. The result is going to be very similar to what has been done for Berlin here. Hopefully ...
12
votes
5answers
2k views

Creating photogrametric point cloud of an object from distributed photographs, here: Making accurate 3D model of building using UAV imagery?

Is there a way of creating a photogrametric point cloud from a set of densly distributed photographs of an object? Application: I am trying to investigate if creating a 3D model (point cloud) of the ...
12
votes
1answer
3k 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 ...
11
votes
1answer
34k 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 ...
11
votes
4answers
14k 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 ...
11
votes
2answers
54k 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 ...
11
votes
1answer
751 views

Assign projection to a satellite image

Today I stumbled upon a picture taken from the ISS looking down Europe and it is really beautiful. So, I started thinking I could add more to the picture. Like world borders, cities, road network, ...
10
votes
2answers
3k views

Automated georeferencing in ArcGIS Desktop?

I am attempting to fully automate the process of georeferencing a load of .png files - i have xml file containing the co-ordinates - but how can i use them? Does anyone have any advice?
10
votes
2answers
460 views

Does a Scanned Map have to be georeferenced in the projection of the original Source?

I have a historic paper map for the Indian Sub-continent which has been scanned. The Map is in Albers Equal Area Conical projection, and has the latitude and longitude grid on it. I was trying to ...
10
votes
1answer
327 views

Georeferencing Museum specimens with poor locality descriptions

I am currently collating a list of specimens from databases of various natural history museums for further research. However, a well known issue associated with majority of historical data is the lack ...
9
votes
1answer
4k views

Batch Georeferencing in ArcMap/ArcPy?

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 ...
9
votes
2answers
13k views

Create a raster with georeferenced information in R

Referring to my previous question, how do I "geocode"/convert - using R - a generated raster image to a format that can be shown as a layer on a map? In short, I'm aiming to recreate the results of ...
9
votes
3answers
742 views

How to outsource scanning and georeferencing maps?

We have some historical paper maps and we want to get them scanned and geo-referenced and ultimately make a seamless map for a particular time. What vendors supply this service? (I have found ...
9
votes
3answers
3k 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 ...
9
votes
1answer
3k views

Georeferencing LAS files in geographic coordinates (lat/lon) or in cartesian (projected) ones?

First of all, I am a newbie in GIS. I have a lidar point cloud with GPS and telemetry data associated. Then, I transform coordinates of every point to an ECEF coordinate system and finally I ...
9
votes
1answer
5k views

Is there image editing software that will not alter a GeoTIFF's embedded georeferencing?

I know there are a couple workarounds for this but I was hoping a direct solution exists. I am looking for an image editor (like Photoshop but hopefully free software) which can be used to edit ...
8
votes
3answers
3k 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 ...
8
votes
2answers
12k 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 ...
8
votes
2answers
781 views

Geo-referencing an old map

I'm trying to georeference this part of an old map of Indochina. . The full extent gives more information: . To do so, I used QGIS and tried to infere the datum, I tried "Unknown datum based on ...
8
votes
1answer
7k views

Transformation types in geo-referencing of QGIS?

I am a beginner in geomatics. I am trying to georeference some images in QGIS. I would like to understand what is happening behind the different transformation types (linear, polynomial, Helmert...)....
8
votes
2answers
2k views

Georeferencing 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 ...
8
votes
1answer
2k views

ISIS to GDAL to QGIS: Georeferencing Mars Images

I'm trying to use QGIS to view some images from the Mars Reconnaissance Orbiter Context Camera. I use ISIS3 to download the images and convert them to mapped .cub files, following the instructions ...
8
votes
1answer
273 views

Georeference raster in non horizontal plane

We have raster data which is generated from (vertical) walls. We would like to keep this data in a postgis database and have the spatial reference encoded "the most accurate way". Currently, they are ...
7
votes
5answers
4k views

Georeferencer plugin will not load in QGIS

I have downloaded and installed QGIS. I would like to georeference an image using the core georeference plugin. When loading it no toolbar appears and the 'update', 'reinstall' etc boxes in plugin ...
7
votes
4answers
5k 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 ...
7
votes
3answers
1k views

Creating disease risk map in QGIS? [closed]

I would like to create a risk map using RFE Data and Tiffs but now I realised that I actually have no idea how. I have dowloaded .Tiff(Region), .hdr and .bil(Rainfall/RFE) files from the USGS page, ...
7
votes
5answers
23k views

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 ...
7
votes
5answers
2k 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 ...
7
votes
3answers
1k views

Merge images first, or georeference first?

I'm wanting to georeference and vectorise some features from scans of the OS 1896 Town Plans that I have purchased from the NLS (http://maps.nls.uk/os/london-1890s/info.html). The scans provided are ...
7
votes
2answers
9k 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 http://www.shadedreliefarchive.com/...
7
votes
2answers
240 views

How to keep track of changes to geo-referenced data and maps?

At my company we are starting to get more serious about keeping track of changes to our geo-referenced data and maps. I'm looking into this and am wondering how people do it at other companies. We ...
7
votes
1answer
708 views

Why is QGIS georeferencer much faster on Windows than Mac?

I just went from temporarily using a Windows 7 machine with 4GB of RAM and no video card as far as I know. I'm now using a mac with 16GB of ram, etc. Its a much more powerful machine. However, QGis's ...
7
votes
1answer
841 views

Determining Natural Origin for a GeoTIFF file (Lambert Conic)

I am trying to display an existing GeoTIFF file (from the FAA WAC set) in an application that requires the GeoTIFF NaturalOriginLongitude tag (FalconView 5.1.1). There are some older files in that set ...