Expand the install parameters in cnHeat

We are requesting the ability to manually override the antenna tilt angle used in cnHeat viewshed and coverage calculations to support custom mounting configurations.

Background

We operate 4600 APs in terrain that requires more mechanical downtilt than the standard AP bracket allows. We fabricated custom brackets to achieve the necessary angles, but cnHeat is constrained by the default bracket tilt range — so the viewshed it generates does not reflect our actual installed configuration. The resulting coverage model is inaccurate, which limits our ability to use cnHeat for planning and validation on these sites.