How to refine obstructed horizon

[theskyhound]

If you are using your scope mounted equatorially, then the Dobson's hole option doesn't apply. In that case you will just have to keep in mind that things that are overhead aren't accessible. You can pick targets from a chart, for example, or see how long it takes after the SkyTools "start" time for objects overhead to typically appear below your roof, and add that amount of time for objects near the zenith.