Toronto is actually very fortanate to have someone like Daniel Tonks kind enough to compile a list of all OTA stations and keep it updated regularely.

I've searched for Channel Maps like his for many US cities and found nothing. You would think NYC would have an OTA site like remote central, but i looked and couldn't find one.

a city like Ottawa doesn't have a big enough OTA market anyways. Theres 2 stations right now. Although maybe you could be the one to start up the channel map for Ottawa.