NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Longitude by calculator -theodolite
From: G Becker
Date: 2013 Jul 4, 10:23 -0400
From: G Becker
Date: 2013 Jul 4, 10:23 -0400
I left off “where I live in America”… ;). It is taught here in tech schools and colleges, but seldom used in the field. I can hardly speak for all surveyors, but I have never witnessed anyone use it in the field. I have only been surveying for 25 years, so I cannot speak for the older crowd. When I started, total stations were the new thing and most bearing references were magnetic. When GPS came out, it took over. There are two separate survey systems in America, PLSS and Colonial. I practice in a Colonial state, which uses a unique set of rules.
-----Original Message-----
From: NavList@fer3.com
[mailto:NavList@fer3.com] On Behalf Of Richard
B. Langley
Sent: Thursday, July 04, 2013 9:56
AM
To: george@gwbeckerpls.com
Subject: [NavList] Re: Longitude
by calculator -theodolite
"surveying astronomy is a dead art" -- Not quite, at least not for UNB GGE graduates. I still teach astronomical azimuth determination using sun shots with a theodolite. The Star Almanac for Land Surveyors is still published:http://astro.ukho.gov.uk/nao/publicat/sals.html -- Richard Langley On Thursday, July 4, 2013,185, at 10:44 AM, G Becker wrote: > Honestly, surveying astronomy is a dead art. Theodolites were the last link to astronomical observations. Survey equipment suppliers frown on sun shades for Total Stations. They claim the optical sensors can be damaged by the sun. I think it is more of a GPS sales tactic. Now back on subject, 2008 was the last year of a published American surveyor ephemeris ( http://www.rollanet.org/~eksi/Handbook.htm ). Another website �web publishes� a survey ephemeris� accuracy of the ephemeris is unknown. ( http://www.cadastral.com/index.html )> > > > -----Original Message-----> From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Richard B. Langley> Sent: Thursday, July 04, 2013 9:01 AM> To: george{at}gwbeckerpls.com> Subject: [NavList] Re: Longitude by calculator -theodolite> > Subject: geodesy> One who practices it: geodesist> > But many professional geodesists don't know how to take or reduce theodolite measurements. ;-) On the other hand, surveying (or geomatics) engineers (should) know how to obtain precise and accurate results from a theodolite (or a total station).> > Don't forget, we have a lot of relevant (oldish but still relevant) publications for free download here:> http://gge.unb.ca/Pubs/LectureNotes.html> > -- Richard Langley> > On Thursday, July 4, 2013,185, at 9:42 AM, G Becker wrote:> > > Hello:> > > > I decided to start this as a new topic. My goal is to see how precisely I can determine my location using my theodolite (read scale to 3 seconds of arc).> > > > Thank you.> > > > Bruce> > > > > > Bruce,> > > > This is one of my favorite subjects. Listed below is a good reference which can be downloaded from the NOAA website. The Navlist has a resident Geodist*, so I'll attempt to not comment on this subject.> > > > 1.) Manual of Geodetic Astronomy : Determination of Longitude, Latitude, and Azimuth by Albert Hoskinson and J Duerkesen, Special Publication No 237. In the preface of this book, beginning on page IX, it lists the reference material which also can be downloaded from the NOAA website. Most can be found in various Appendixes of the Annual Report of the Coast Survey.> > > > 2.) If you want to purchase a book.. The Elements of Astronomy for Surveyors by J B Mackie. This book has been reprinted many times, I have the 8th edition (1982). Each chapter has a list of references.> > > > 3.) Geodesy by Alexander Clarke. ( http://books.google.com/books?id=ECUJAAAAIAAJ&source=gbs_navlinks_s ) Most "geodesy" books reference this one.> > > > > > * I'm not sure if Geodist is the current politically correct term for a person who geodeticals.> > ----------------------------------------------------------------> > NavList message boards and member settings: www.fer3.com/NavList> > Members may optionally receive posts by email.> > To cancel email delivery, send a message to NoMail[at]fer3.com> > ----------------------------------------------------------------> > > > : http://fer3.com/arc/m2.aspx?i=124568> > > > -----------------------------------------------------------------------------> | Richard B. Langley E-mail: lang{at}unb.ca |> | Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ |> | Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 |> | University of New Brunswick Fax: +1 506 453-4943 |> | Fredericton, N.B., Canada E3B 5A3 |> | Fredericton? Where's that? See: http://www.fredericton.ca/ |> -----------------------------------------------------------------------------> > : http://fer3.com/arc/m2.aspx?i=124569> > : http://fer3.com/arc/m2.aspx?i=124570> -----------------------------------------------------------------------------| Richard B. Langley E-mail: lang{at}unb.ca || Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ || Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 || University of New Brunswick Fax: +1 506 453-4943 || Fredericton, N.B., Canada E3B 5A3 || Fredericton? Where's that? See: http://www.fredericton.ca/ |-----------------------------------------------------------------------------
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