Are you running ENVI 5 SP3 or the newly released ENVI 5.1? Accuracy assessment using Ground Truth image should be present in the toolbox in these versions.

You refer to the 'toolbox' so I assume you are using ENVI 5 vs. Classic. Since you don't have a ground-truth image my first inclination would be to do an estimated accuracy assessment using ground-truth ROIs based on visual identification of sites instead, but a previous post (http://www.exelisvis.com/Support/Foru...) seemed to indicate that tool was not available in ENVI 5. So I'll have to think on that a bit more. Regarding why you cannot find the 'Confusion Matrix Using Ground Truth Image" tool, I am not aware of any special licenses/extensions needed to access that tool so if it is not showing in the toolbox under the Classification -> Post Classification folder I would recommend you contact tech support.

I have ENVI 5.0 Version, and build 04/18/12. I also found the tutorial files mentioned about Accuracy assessment tools using ground truth image, however I cannot find the above mentioned tool for creating the confusion matrix. Here is a link that shows my toolbox options: http://s17.postimg.org/du3nxddgv/Toolbox.jpg

Yes, the Confusion Matrix was added in a service pack for ENVI 5 so you would need the latest service pack (SP3) for ENVI 5 or ENVI 5.1, which was released this week.