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Solar Observation Program
Posted by Gerry Pena on August 18, 2014 at 6:02 amMy GPS conked on me during a survey so I had to use solar observations to determine the azimuth of survey. Upon reaching the office, I could not find the software that I use to compute the azimuth. Apparently last time I used it was maybe before 2008! Since then my PC has changed & reformatted several times & I may have missed backing the software up.
Any of you guys recommend a freeware? I recorded the time, hor angle & vertical angle of the 4 sides of the sun.
Thanks.Gerry Pena replied 9 years, 7 months ago 7 Members · 12 Replies- 12 Replies
You can use the algorithms in http://www.rollanet.org/~eksi/Handbook.htm the old Leitz Ephemeris to solve your problem.
You will need a current ephemeris. Here is a link to Mr Wahl’s http://www.cadastral.com/2014ephs.htm
The only issue is getting the azimuth in the correct quadrant.
Thanks for the links. Wow now I need to refresh on my spherical trigonometry.:-O
Did not remember that the math was difficult 20 years back then.I have a few old programs that I got from somewhere. Probably fellow posters here or on the old board.
Here is a link to them on Dropbox.
Solar-Star programsI tried to get them to work on my windows 8 laptop, without success. They will probably work on an older PC.
Good luck.
I have an excel spreadsheet to compute hour angle. One version automatically provides ephem data for this current year.
If interested, shoot me an email.
– jerry
There is a program called “Spade” that is pretty simple to use and is a freebie.
I’ve had good results using it for Polaris.
It is a DOS program that is several years old, but I’m sure it is still good for Polaris. I wonder if it is still accurate enough for solar.
http://www3.sympatico.ca/craymer/software/spade/
ftp://ftp.geod.nrcan.gc.ca/pub/GSD/craymer/software/spade/spadedoc.txt.> I’ve had good results using it for Polaris.
>
> It is a DOS program that is several years old, but I’m sure it is still good for Polaris. I wonder if it is still accurate enough for solar.
> http://www3.sympatico.ca/craymer/software/spade/
> ftp://ftp.geod.nrcan.gc.ca/pub/GSD/craymer/software/spade/spadedoc.txtBill:
I checked some of my older solar calc’s that I made using a modified version of the Elgin/Knowles program in the Lietz Ephemeris for the HP71C that I had my youngest boy redo for my HP75C due to language difference in the 2 units and added some printout goodies with notations to go along with the printed data. Anyway, the two reductions checked each other within 10ths of seconds or maybe 1 or 2 seconds, which I thought was no biggie.
The Elgin/Knowles modified program was good for either solar or polaris observations and all you had to do was enter the data required for a solar or polaris shot. I could do each individual pointing in order to evaluate any out of reason pointing or do the average of the D1/R3, D2/R3, and D3/R1 readings.
>I checked some of my older solar calc’s
I was thinking in terms of outdated ephemeris, not in terms of basic calculations.
.> >I checked some of my older solar calc’s
>
> I was thinking in terms of outdated ephemeris, not in terms of basic calculations.I guess I don’t know what you mean by “outdated ephemeris”. Jerry Wahl is about the only one I think that works up a yearly ephemeris now, except for maybe the H.M. Nautical Almanac Office in London. I haven’t checked with the Naval Observatory to see if they still issue one. In order to use my Solar transit, I need to convert the old Lietz or Jerry’s ephemeris by + or – 12 hours since the BLM quit publishing theirs in 1988.
You do not need to compute an entire year’s ephemeris to do this. It’s pretty straightforward to just compute it for only the observations you make at the time. Once the transformations are programmed, it’s trivial. The programming is the most time-consuming; everything else just needs key strokes.
Cliff:
I only did the 12hr +/- conversion to the BLM format only for the day that I planned to make an hour angle observation in order to make up a Dec sheet for the solar transit. Due to a slight error in the solar attachment, I only took a solar with the attachment to verify my hour angle reductions for the line bearing in order to catch a calculation error. Also, I would use the solar attachment to get a bearing in order to perform a quick search for the direction of a line being retraced and monument search.
I can send you a copy in Word of the documentation of how I perform the conversion if you would like and maybe you could tell me a better procedure. I can also include the notes of an observation and the results for the line bearings.
Thanks for all the suggestions. Downloaded the SPADE software & was able to use it even if still in DOS. I like the fact that you don’t have to enter any ephemeris data.
Thanks to everyone.
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