Re: azimuth diagram
Hi Frank, You are constructing a sun compass with the Weir diagram, based on the analemmatic sundial. A lot has been written about. Have a look in Compendium, september 2003 for the article From Universal Analemmatic To Sun Compass - Filling The Gaps by Frederick W. Sawyer Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: Frank Evans [EMAIL PROTECTED] To: Sundial sundial@rrz.uni-koeln.de Sent: Thursday, February 03, 2005 10:18 PM Subject: azimuth diagram Greetings fellow dialists, The other day I bought a copy of Weir's Azimuth Diagram. This was the first time I had seen it although I had read about it in earlier days. It is a remarkable document, devised by Captain Weir in 1890. Its purpose is to enable a navigator to find the azimuth of a heavenly body by graphical means. In appearance it is a circle of 50 cm diameter on paper, containing a central vertical ordinate, a series of concentric ellipses and mirrored hyperbolic curves spreading from the central ordinate. It makes a very pretty picture and is in colour. The diagram is entered with the elements latitude (expressed as an ellipse), declination of the heavenly body (expressed linearly on the vertical ordinate) and the hour angle (crudely, sun time) of the heavenly body (expressed as a hyperbolic curve). Marking the declination on the vertical ordinate (which is pricked out in degrees from 65N to 65S) and joining this point to a second point where the appropriate latitude ellipse crosses the hour angle hyperbola gives a line which plots the azimuth of the heavenly body in question. It occurred to me that this graphical method of solving azimuth problems could be modified to make a sundial. If the Weir diagram were to be levelled and oriented N and S and a vertical shadow pin were placed on the central ordinate at the sun's declination then the shadow would represent its azimuth. Follow this until it reaches the appropriate latitude curve and read off the time from the conjoined hour angle curve. Two points (1) This diagram is a fascinating survival, last printed in 1950 and still obtainable from UK Admiralty chart agents. It is catalogued as chart no. 5000 and is printed on good quality chart paper. It costs 5 pounds 50. There is a second diagram available for the hardy ones, extending from 65 deg to 80 deg. (2) Have I got all this right? Is anyone else familiar with Weir's diagram and has it been mentioned before in this sundial group? Frank 55N 1W - -
Re: azimuth diagram
is there a picture available? It might make the text a lot clearer. Thibaud Chabot At 22:18 03-02-2005, Frank Evans wrote: Greetings fellow dialists, The other day I bought a copy of Weir's Azimuth Diagram. This was the first time I had seen it although I had read about it in earlier days. It is a remarkable document, devised by Captain Weir in 1890. Its purpose is to enable a navigator to find the azimuth of a heavenly body by graphical means. In appearance it is a circle of 50 cm diameter on paper, containing a central vertical ordinate, a series of concentric ellipses and mirrored hyperbolic curves spreading from the central ordinate. It makes a very pretty picture and is in colour. The diagram is entered with the elements latitude (expressed as an ellipse), declination of the heavenly body (expressed linearly on the vertical ordinate) and the hour angle (crudely, sun time) of the heavenly body (expressed as a hyperbolic curve). Marking the declination on the vertical ordinate (which is pricked out in degrees from 65N to 65S) and joining this point to a second point where the appropriate latitude ellipse crosses the hour angle hyperbola gives a line which plots the azimuth of the heavenly body in question. It occurred to me that this graphical method of solving azimuth problems could be modified to make a sundial. If the Weir diagram were to be levelled and oriented N and S and a vertical shadow pin were placed on the central ordinate at the sun's declination then the shadow would represent its azimuth. Follow this until it reaches the appropriate latitude curve and read off the time from the conjoined hour angle curve. Two points (1) This diagram is a fascinating survival, last printed in 1950 and still obtainable from UK Admiralty chart agents. It is catalogued as chart no. 5000 and is printed on good quality chart paper. It costs 5 pounds 50. There is a second diagram available for the hardy ones, extending from 65 deg to 80 deg. (2) Have I got all this right? Is anyone else familiar with Weir's diagram and has it been mentioned before in this sundial group? Frank 55N 1W - - Thibaud Taudin-Chabot 52° 18' 19.85 North, 04° 51' 09.45 East, alt. -4.50 m home email: [EMAIL PROTECTED] -
RE: azimuth diagram
Frank, Have a look at BSS Bulletin 13(ii) and 13(iii) where I think Tony Belk discusses the Weir diagram - he may also have written or talked about it more recently if my memory serves me. Andrew James -Original Message- From: Frank Evans [mailto:[EMAIL PROTECTED] Sent: 03 February 2005 21:18 To: Sundial Subject: azimuth diagram Greetings fellow dialists, The other day I bought a copy of Weir's Azimuth Diagram. ... (2) Have I got all this right? Is anyone else familiar with Weir's diagram and has it been mentioned before in this sundial group? Frank 55N 1W PRI Limited, PRI House, Moorside Road Winchester, Hampshire SO23 7RX United Kingdom Tel: +44 (0) 1962 840048 Fax: +44 (0) 1962 841046 www.pri.co.uk The Intelligent Metering Company This correspondence is confidential and is solely for the intended recipient(s). If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. This message has been scanned for viruses by MailControl -
Re: Ceiling Dial?
Hello Brook, to calculate the exact values of the position of the Sun in sky, you may use the program SUN_EPH that has been attached to Compendium June 2003, Email version. The values that I have obtained are the same of those of Fritz Stumpges (with differences of few arc second) To calculate the angles of the mirror (declination and inclination) are needed : two observations , the knowledge of the distance between the mirror and the ceiling and the coordinates of the two light spot, in a system with the origin in the point where the vertical through the center of the mirror touch the ceiling. In the group of programs REFLSUN, attached to the number of March 2004 of Compendium, there is a program written just to do this kind of calculation. It usefull when we dont know haw the mirror is and if the mirror has had a displacement during its fixing. If you want I can send the two programs attached to Email messages (900 kbs and 2100 kbs). Best Gianni Ferrari 44° 39' N 10° 55' E Mailto : [EMAIL PROTECTED] -
RE: azimuth diagram
Hello Thibaud For those who do not have the NASS or BBS articles, here is a link to a Weir azimuthal diagram located by Google. http://www.ilstu.edu/microcam/map_projections/Azimuthal/Littrow.pdf Roger Bailey -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Th. Taudin Chabot Sent: February 4, 2005 1:54 AM To: Sundial Subject: Re: azimuth diagram Frank, is there a picture available? It might make the text a lot clearer. Thibaud Chabot - -
Re: azimuth diagram
Hi Mac, I once wrote a program Foster, not completed to the end but a sun compass is included. The output file may be used as input for ZW2000. I think I sent it to you. If not, ask me and I will do so. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: Mac Oglesby [EMAIL PROTECTED] To: Fer J. de Vries [EMAIL PROTECTED] Sent: Friday, February 04, 2005 5:29 PM Subject: Re: azimuth diagram Hi Fer, I think I remember that one of your programs draws a sun compass, but can't remember which one. Help? Best wishes, Mac Hi Frank, You are constructing a sun compass with the Weir diagram, based on the analemmatic sundial. A lot has been written about. Have a look in Compendium, september 2003 for the article From Universal Analemmatic To Sun Compass - Filling The Gaps by Frederick W. Sawyer Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring mailto:[EMAIL PROTECTED] http://www.de-zonnewijzerkring.nl Home mailto:[EMAIL PROTECTED] http://www.iae.nl/users/ferdv/index-fer.htm Eindhoven, Netherlands lat. 51:30 N long. 5:30 E - Original Message - From: Frank Evans [EMAIL PROTECTED] To: Sundial sundial@rrz.uni-koeln.de Sent: Thursday, February 03, 2005 10:18 PM Subject: azimuth diagram Greetings fellow dialists, The other day I bought a copy of Weir's Azimuth Diagram. This was the first time I had seen it although I had read about it in earlier days. It is a remarkable document, devised by Captain Weir in 1890. Its purpose is to enable a navigator to find the azimuth of a heavenly body by graphical means. In appearance it is a circle of 50 cm diameter on paper, containing a central vertical ordinate, a series of concentric ellipses and mirrored hyperbolic curves spreading from the central ordinate. It makes a very pretty picture and is in colour. The diagram is entered with the elements latitude (expressed as an ellipse), declination of the heavenly body (expressed linearly on the vertical ordinate) and the hour angle (crudely, sun time) of the heavenly body (expressed as a hyperbolic curve). Marking the declination on the vertical ordinate (which is pricked out in degrees from 65N to 65S) and joining this point to a second point where the appropriate latitude ellipse crosses the hour angle hyperbola gives a line which plots the azimuth of the heavenly body in question. It occurred to me that this graphical method of solving azimuth problems could be modified to make a sundial. If the Weir diagram were to be levelled and oriented N and S and a vertical shadow pin were placed on the central ordinate at the sun's declination then the shadow would represent its azimuth. Follow this until it reaches the appropriate latitude curve and read off the time from the conjoined hour angle curve. Two points (1) This diagram is a fascinating survival, last printed in 1950 and still obtainable from UK Admiralty chart agents. It is catalogued as chart no. 5000 and is printed on good quality chart paper. It costs 5 pounds 50. There is a second diagram available for the hardy ones, extending from 65 deg to 80 deg. (2) Have I got all this right? Is anyone else familiar with Weir's diagram and has it been mentioned before in this sundial group? Frank 55N 1W - -
FW: Re: Ceiling Dial?
-- Forwarded Message: - From:[EMAIL PROTECTED] To: Brooke Clarke [EMAIL PROTECTED] Subject: Re: Ceiling Dial? Date:Fri, 04 Feb 2005 18:37:37 + Brooke, you received some good answers. Fritz Stumpges hand calculated the answer, Roger Bailey suggested the Dialists Companion and Gianni Ferrari suggested the SUN_EPH. Just to show that there is more than one way to get the answer, I used my Solar Position PostScript application that I wrote back before I knew about those other application. I just type in the parameters and Viola! the results for each date/time/location.. I posted the two PDF files at http://home.comcast.net/~rlh-pr/clarke/ they also show the answers. Robert Hough Shadow Master 32.37 N 111.13 W Hi: Some months ago I started marking the ceiling to show when I get satellite outage. I have since been making dots on the ceiling and noting the time and date. Today, 3 Feb. 2005 the Sun at 12:00:00 noon was at the same place it was on 6 Nov. 2004 and if I read my writing correctly at 11:30:00. I'm located at 39:11:24.6 North, 123:09:50 West. Can someone check the Sun's position on these two dates and times? At some point in the future I might be able to measure the location or relative location of the marked points and knowing the dates and times do a best fit to determine the room and mirror geometry. Has anyone done this? Thanks, Brooke Clarke, N6GCE -- w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com - -
