FW: Google Method of Finding DeclinationHi John, Thanks for publishing this technique. I would recommend your technique when it is important to get it right. If a customer wants a precisely crafted sundial, your technique is almost as good as being there and using Tony's wonderful declinometer.
For more casual uses, I would recommend Damia Soler's web link. http://sundial.damia.net/ This now works like a charm. Click on two points on a Google Map to produce a line with text indicating the location with lat and long noted as well as the correctly calculated the wall declination. The result is now within a degree of what I had found with Google Earth methods. Google Maps is pretty good for resolution, although Goggle Earth gives 3 D effects. Results vary but around here the Google camera car has been taking ground level pictures so we can expect pretty good resolution in the future. I recently gave the Google camera car an appropriate salute as it passed. I have found Yahoo Maps to give somewhat better resolution but the web link is based on Google Maps. If the building is too small to give you a clear line, use the adjacent road as your baseline. Damia's web link also gives you the standard hour lines. If nothing else this is a good check for the professional design. Regards, Roger Bailey Walking Shadow Designs From: John Carmichael Sent: Wednesday, June 24, 2009 7:38 PM To: 'Sundial List' Subject: FW: Google Method of Finding Declination Hi Walter (Hope you don't mind if I cc Sundial List) Ok- I'll try to describe it. Finding Wall Declination using Google Earth 1. Download and install the latest version of Google Earth which has clearer and better images. See: http://earth.google.com/ 2. Open GE and find the location. Zoom in or out to get the clearest view of the wall or roofline. Make sure North (the "N" on the compass) is straight up. 3. Click on "File" then "Save" then "Save Image". An Explorer window appears. Give it a name and save it as a .jpg in your files. 4a. If you don't have a CAD program, then print the photo on a piece of paper. 4b. If you do have a CAD program (I use DeltaCAD), then import the photo into it. 5. Draw a line over the photo of the wall or the roof line above the wall that will have the sundial. 6. Draw a north-south line that intersects the wall or roof line. 6a. If using a paper print, measure the angle of declination (degrees East or West of South) of the wall or roof line, using a protractor. 6b. If using CAD, measure the angle of declination by using the angle dimension tool. Done! p.s. There is another Satellite image website that sometimes has better satellite images than Google Earth. It's called "Bing Maps" (formerly call Virtual Earth). See: http://www.bing.com/maps/?FORM=ZZLH8# Use it the same way as Google Earth. -----Original Message----- From: Walter Sanford [mailto:[email protected]] Sent: Wednesday, June 24, 2009 2:35 PM To: John Carmichael Subject: Google Method Can you explain the "Google method" for finding declination? I can imagine how the process works. Question is, what are the exact steps YOU follow? I wrote to Jim Tallman; he sent a *long* reply I'm going to read right after posting this one. ================================================================= Walter Sanford, Director Carl Sandburg Middle School Center for Sky Awareness 8428 Fort Hunt Road Sandburg Planetarium Alexandria, VA 22308 Fairfax County Public Schools Work: 703-799-6169 -6197 (fax) E-mail: [email protected] Home: 703-765-9392 AMS Project ATMOSPHERE Atmospheric Education Resource Agent & Water in the Earth System (WES) Resource Teacher SCSA, Geosystems, & Camp T-Equity - URL: http://www.wsanford.com/ ================================================================= -------------------------------------------------------------------------------- --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.374 / Virus Database: 270.12.90/2200 - Release Date: 06/24/09 12:49:00
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