Sunday, August 30, 2015

on meridian flips

I think I just figured out how I can avoid a meridian flip with an ISS flyover pass. I think it is simply math. It has to be in the north. More importantly, it cannot rise higher than one's latitude. For us, that's just under 45 degrees. I think when something is below the latitude value and in the north, then it makes the mount move mainly in Declination. My brain started to hurt as I tried to do that math.

I had wondered, briefly, at why I was encountering the meridian with the August 14 pass. On review, in various software apps, I saw the Station rose higher than 45. Actually, as soon as I looked at the chart from Heavens Above, I saw there was an issue. The path went through the Little Dipper, i.e. above Polaris. Stellarium was particularly useful.

Light bulb: I will need to pay more attention to the Highest point Altitude value in the flyover table! This one: 57°. That said, low in the north presents other problems: the roof gable; more air. Maybe I should use a fork mount...

No comments: