Could it be a hold over from the Calgary Police UHF days? I show 462.7125 as Channel 21 Call sign XLP 636.
Edmonton Police still have licensed and do use a number of their old UHF Frequencies in additional to trunked and conventional and simplex 800 frequencies.
I really can't say as it is digital and don't have a scanner that will tell me what type. It is not a steady digital signal and is not on very often. I have had it full strength in the northeast and southwest part of Calgary. Still no other posting in Spectrum Direct. Seems to be on mostly between 0700 and 1800. I do not think it is a hold off from the old CPS UHF days. The only other time I heard digital on the FRS/GMRS frequencies was up near the airport about a year ago. Prior to that, have only heard kids and people backing up trailers on FRS/GMRS frequencies. So still wondering what or who is using digital on this frequency.