nothing by way of open source for RS or GIS software that i know of.... free GIS software would include ArcExplorer or ArcReader...neither would be of much use to you, since you need editing capabilities
I need to be able to subset Geotiff images and preserve the spatial information. The output needs to be a geotiff so i can create a world file in order to put it onto a trimble Recon as a background file.
I know that I can do this with ERMapper, but I don't have it and bossman doesn't want to fork out the cash.
I study GIS/GPS and urban planning in college, but I don't know how much help I can be to you. As far as I know, I would try either PCI Geomatica, or as a long shot, Mr. SID Viewer, but if you can get PCI, then I think you can edit the geotiff without compromising the spatial information.
I'm using 5-metre resolution Ikonos data as a backdrop for doing forest management. We don't do much fancy spectral analysis, but it can be done using some of the higher end software packages (ERDAS Imagine, ER Mapper etc). For the large scale mapping of Forest management, road building, satellite imagery is the only way to go.
Smaller scale stuff like the stratification of different forest types for the purposes of inventory can also be done kinda/sorta, but the satellite technology cant capture data at a resolution that would be useful for this; we are talking sub decimeter pixel sizes here.
Large Scale Aerial photography is far more cost effective for things at smaller scales. Plus you can get them in stereo pairs which enables you to get tree height which then allows you to calculate volumes. Which ultimately is what you are after.
....sorry for the late response....i'd be able to help you out at my work (i'm a GIS Officer)...that is, only if you are an OPS employee (provincial government)...if so, PM me....I could crop the data for you and preserve the spatial reference....if it fucks up i can re-project it or even quickly georeference it...
if you ain't OPS, then maybe you should explain to your boss that you really need the software to get your work done properly...