John, Here is another comment on the errors of optical devices;
There is a teaching film showing wave crests moving to the right while the envelopes of group pulses simultaneously move to the left; demonstrating the potential for errors in laser surveying devices. The configuration for this demonstration is a chain of discrete capacitors and inductors. I leave it to our readers to discover which of these are connected in series and which, are connected in parallel. I showed this film to my students of "Transmission Lines, Fields, and Waves" in a routine undergraduate course at the University of Illinois (in Urbana, IL). Gene. ... >---- Original message ---- >>Date: Sun, 30 Jan 2011 14:00:50 -0800 (PST) >>From: "John M. Steele" <[email protected]> >>Subject: [USMA:49700] Re: [SI] A mole hill into Himalayas >>To: "U.S. Metric Association" <[email protected]> >> >> I did further checking, including looking at Leica >> specs. Those numbers like 1.5 mm + 2 mm/km are not >> worst case specs, they are standard deviations. >> Statistically, we know there is reasonable chance of >> individual measurements having errors out to 2 or 3 >> standard deviations, rarely even more. >> ...
