topic Georectifying a satellite image in ArcGIS Desktop Installation Support Questions

Georectifying a satellite image

BrianKranick — Thu, 13 Nov 2014 22:31:11 GMT

Hello, I'm downloading an image file from Africa . I can unzip the file and pull the .tif into Arc, but what is the best way to georectify it? There seem to be tif.aux and tif.ovr files as well.

thank you!

Brian

Re: Georectifying a satellite image

ChrisDonohue__GISP — Thu, 13 Nov 2014 22:53:13 GMT

Here's some information to help get you started

Fundamentals of Georeferencing a dataset.

http://resources.arcgis.com/en/help/main/10.2/index.html#//009t000000mn000000

You can decide on whether to rectify it after georeferencing.

Chris Donohue, GISP

Re: Georectifying a satellite image

DanPatterson_Retired — Fri, 14 Nov 2014 05:41:52 GMT

The *.tiff files are ready to use in ArcMap. I downloaded data for Ethiopia and the image data had a *.tif and *.tfw....the former is the image data and the latter is the world file. Which area/country did you download the data for? Note also, that at least for some countries the data are in both Geographic (longitude latitude) and projected coordinate (eg UTM)

You will have to use the Define Projection tool to get the images and the shapefiles to line up. In my case the projected images for Ethiopia were in UTM zone 37 and the unprojected data are a GCS, presumably in WGS84 datums

Re: Georectifying a satellite image

BrianKranick — Fri, 14 Nov 2014 23:54:44 GMT

Thank you both again. Yes, "define projection" worked like a charm. I'm working with data over Nigeria at the moment. I just had to put it in WGS84.