NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
GPS Anti-Spoof feature request
From: Peter Monta
Date: 2019 Jul 29, 19:44 -0700
From: Peter Monta
Date: 2019 Jul 29, 19:44 -0700
I've got a feature request for the GPS Anti-Spoof app: terrestrial landmarks. I hope Frank doesn't mind my posting it here for discussion.
In these days of summer in the Northern Hemisphere, the Sun is often too high for an artificial horizon, at least without add-on accessories like a pentaprism to extend the sextant's range. And, if you're like me, you don't have easy access to a sea horizon. One solution could be the use of landmarks. If you're observing from a fixed spot, and you know the direction to a distant landmark, then that's just as good as a sea horizon (in fact better, since the landmark is likely to be at least a few degrees above the true horizon and thus in a better atmospheric path). The direction (i.e. topocentric azimuth and elevation) can be found with (what else?) celestial, using either a sextant or a theodolite.
So in concrete terms, this would be a new type of "horizon" in the app, perhaps called "landmark", for which you could manually enter azimuth and elevation.
Cheers,
In these days of summer in the Northern Hemisphere, the Sun is often too high for an artificial horizon, at least without add-on accessories like a pentaprism to extend the sextant's range. And, if you're like me, you don't have easy access to a sea horizon. One solution could be the use of landmarks. If you're observing from a fixed spot, and you know the direction to a distant landmark, then that's just as good as a sea horizon (in fact better, since the landmark is likely to be at least a few degrees above the true horizon and thus in a better atmospheric path). The direction (i.e. topocentric azimuth and elevation) can be found with (what else?) celestial, using either a sextant or a theodolite.
So in concrete terms, this would be a new type of "horizon" in the app, perhaps called "landmark", for which you could manually enter azimuth and elevation.
Cheers,
Peter
