NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Teaching a Running Fix
From: Lu Abel
Date: 2009 Dec 12, 13:03 -0800
From: Lu Abel
Date: 2009 Dec 12, 13:03 -0800
Joe: I've taught this many times. The way I explain it to my students is to tell them to imagine that at the time of the first bearing the sighted object suddenly clones. One of the clones stays in the original position. The other clone moves on exactly the same course and at exactly the same speed as the vessel. I demonstrate to them that the bearing to the moving clone stays the same as the vessel advances, but the position of the bearing line moves along with the vessel. You then take a second bearing back to the original object and cross the two. Most of them say the image of the clone of the lighthouse moving along with the vessel helps them understand the (not naturally intuitive) concept of advancing a line of position. In fact, I put this into a set of PowerPoints that won a national award from the US Power Squadrons. I can send you a copy off-line if you desire (or, if there is demand, I can post it in the archives)\ I work in high-tech and have lived in high-tech areas (first Boston and now Silicon Valley) and my classes have always been a challenging combination of engineers and other way less mathematically proficient people. Teach currents? The engineers say "easy, it's vector math, let's go on to the next topic" while the others' eyes glaze over.... So I've always found a challenge in explaining concepts (like running fixes) in ways that won't bore the engineers while helping get the non-engineers on board. Lu Abel joseph_schultz@rrv.net wrote: > A challenge, in the spirit of the intention of this list, which is the promotion of the use of traditional navigation techniques. > > You're tutoring a small group of new navigators. Normal people, ranging in age from 12 to "retired." > > Here's what they can do on a paper chart/map: > 1. Plot a track. > 2. Plot and label DR positions, using > > distance = speed x time > > 3. Plot and label a line-of-position to a visual object, understanding that it take two or more simultaneous LOPs to constitute a fix. > > Your mission, if you choose to accept: close the schoolbook. Explain, in words your students can understand, the concept of a running fix. > > No grades, no judgement. I'm interested in learning how you'd teach it. > > Joe > > -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com