It should be roughly correlated with latitude (the exceptions being panels on sloped roofs which will match the roof slope).
Tilt should correlate to latitude for panels with an azimuth due South.
For panels with east/west azimuth, the tilt should correlate with where the sun is at 7-8AM and 17-18PM, at least in my area.
((I think you have your concept of azimuth and tilt mixed up; I know I have when I was originally typing a different parent comment)
alt Hacker News
Tilt should correlate to latitude for panels with an azimuth due South.
For panels with east/west azimuth, the tilt should correlate with where the sun is at 7-8AM and 17-18PM, at least in my area.
((I think you have your concept of azimuth and tilt mixed up; I know I have when I was originally typing a different parent comment)