4 ms·
Yeah, maybe we can have a "digital" sextant that instead of relying on specialized training to humans, just pushes all the sextant data plus altitude, barometer
by sn_master 5y ago
Yeah, maybe we can have a "digital" sextant that instead of relying on specialized training to humans, just pushes all the sextant data plus altitude, barometer, universal time (UTC), timezone and sunset/sunrise from a perpetual calendar and such inputs to an android gizmo that gives us an approximate location, something that can be sold commercially for hikers, boaters and everyone for fun.
- mikewarot 5y agoA sextant requires a flat level horizon, and sky clear enough to see the sun, or stars at night, and a compass that indicates true north (with correction for magnetic declination). In an urban environment, there is usually not a clear shot at a flat horizon, nor an area free from metal structures for far enough to get an accurate magnetic north.
- therein 5y agoAll the more reasons to use something digital, isn't it? Would make it much easier to figure out the horizon without actually seeing it.
- throw0101a 5y agoOr you can simply buy an artificial horizon for less than US$ 40: * https://www.davisinstruments.com/product/artificial-horizon/ https://www.davisinstruments.com/product/artificial-horizon/ * https://www.starpath.com/catalog/accessories/1840h.htm https://www.starpath.com/catalog/accessories/1840h.htm * https://www.celestaire.com/product/davis-artificial-horizon/ https://www.celestaire.com/product/davis-artificial-horizon/ They've been around since (at least) 1907: * https://www.scientificamerican.com/article/an-artificial-horizon-for-sextants/ https://www.scientificamerican.com/article/an-artificial-hor...
- sn_master 5y agoShouldn't a gyroscope compensate or at least allow getting flat level? I think maybe they didn't use it because they didn't have accurate gyroscopes we have now. For clear shot, would tiny drones that go up work? How high do we need to get a clear shot?
- mikewarot 5y agoGo outside, do you see a flat level horizon? You could use the accelerometer to get a good idea of "down" but not enough resolution for navigation.
- salawat 5y agoYou cannot escape the burden of training people to do it, because someone has to check the machines figures for drift due to defect, improper implementation, or damage. See the Patriot missile systen fiasco.
- VistaBrokeMyPC 5y agoNavy also uses inertial navigation. It needs to be calibrated with GPS every now and then but you can get away without a GPS downlink for a while before drift becomes a problem.
- nradov 5y agoAutomated stellar navigation systems have been around for decades. https://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-could-be-the-key-to-winning-future-fights-in-gps-denied-environments https://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-cou...