I routinely use Google Earth to determine wall declination. Depending on the quality of the picture, resolution to within one degree can be achieved. The default orientation for Google Earth is straight north up for the center of the starting image. I have a flat screen with vertical sides and horizontal top and bottom that are useful reference lines. Check your screen settings. On most displays these days, x and y are not equal. I had to choose a display settings to match the dimensions of the monitor.
There are examples of wall declination using Google Earth in some of the presentations on my website. "Timelines" #5 may be the most useful. Regards, Roger Bailey Walking Shadow Designs www.walkingshadow.info -------------------------------------------------- From: "Damia Soler Estrela" <[email protected]> Sent: Monday, June 08, 2009 5:53 AM To: "Sundial List" <[email protected]> Subject: Wall declination using google earth > > Hello: > > You are talking about physical declinometers in order to know the > wall declinations, I think that is the most acurrate method, but I have > been using google earth, you can see the wall of the buildind or the > aligned street, and could calculate the declination from North? (You > have a rule to measure the x and y axis, or read the coordinates). > > What do you think about the accuracy of this method? > Do you have any information about the accuraccy of google earth in > order to measure declination? > > > Best regards > Damià > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.339 / Virus Database: 270.12.55/2160 - Release Date: 06/07/09 > 05:53:00 > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
