NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Index corr., Octant as dipmeter
From: Alexandre Eremenko
Date: 2004 Nov 23, 11:32 -0500
From: Alexandre Eremenko
Date: 2004 Nov 23, 11:32 -0500
Jared, I did as you recommended, and found the paper http://www.agu.org/sci_soc/prrl/prrl9825.html which begins with the words: "Over-the-horizon (OTH) radar systems were first developed during the Cold War..." In general, there are two kinds of radars used in artillery: the detection radars (which find the target) and distance-measuring radars (which are used to direct the gun). I think all "over the horizon radars" should be of the first kind. As I understand, you cannot measure the distance accurately by a reflected ray. But I admit that my artillery education may be a bit out-of-date: I was trained in this area in 1970-s. For finding the distance, we used two devices: an optical range-finder with base approx. 2.5 meters, and a radar. The radar was substantially less precise in both distance and direction finding, so it was used only at night or when the clouds obscured the sky. On Tue, 23 Nov 2004, Jared Sherman wrote: >in the same way our vision is.> > > It isn't quite the same. Google "radar over the horizon" to see how > extensive this is these days. I don't know if this was being exploited at > all in WW2 but suspect even then, the radar horizon was known to be beyond > the visual horizon. Radio waves tend to skip and bounce, so even then the > engineers would have been aware that they could exceed visual horizons, even > if only slightly.