[aprssig] GO-32 Spreadsheet

gerheim at cox.net gerheim at cox.net
Tue Oct 23 11:48:27 CDT 2007

The attached Excell spreadsheet will allow you to create your own GO-32 chart.  The algorithm is motivated by Bob Bruninga's observation that the orbit repeats itself every 9 days.  (plus or minus a few minutes - Just stay on "Lombardi Time", and you'll be OK till April.)

To use it, go to http://www.amsat.org/amsat-new/tools/predict/, and indicate GO-32, your location, and 50 passes.  You may actually need more than 50 passes.  I'll talk about that later.  

When the prediction table comes back, highlight all the numbers in the table, but not the column headers.  Then "Copy" the highlilghted area (control-c).  
Open the attachment, go to the sheet "Data from AMSAT" (see the tabs near the bottom).  Highlight cell A1 (upper left cell), and "Paste" (control-v).  

Go to the sheet "AOS Chart" (again, the tab is near the bottom).  

Set your time zone in cell F1.  The default is -4, EST.  

The Day Numbers (column C) should go up to 9, then loop around for at least 1 pass with Day Number 1.  This will mean the cycle is completed.  Save the chart to your PC whether it's complete or not.  

If the Day Numbers don't loop around to "1", then wait a while.  A day should do it.  Then you open the saved version of the attachment, and repeat the entire process with only one difference.  

When you paste the new data to the AOS Chart, you do _not_ highlight cell A1.  You highlight whatever cell corresponds to the _new_ top row of the table on the AMSAT page.  You overlay that row, and let the rest go where it will.  It should extend beyond the bottom of the original data.  

So, on this second run, you're going to highlight all the numbers in the chart on the AMSAT page, then go to the spreadsheet you saved earlier, highlight cell A1, A2, A3, or whatever..., so that row matches the top row from the AMSAT chart.  _Then_ you "Paste" the data (control-v).  

If you open the attachment weeks or months from now, it should update the "Day Number" in cell B1.  

I'm not sure what happens if you try to "trim-out" the low-elevation passes.  I recommend that you highlight the rows corresponding to the high-elevation passes.  (Highlight the rows, Right-click, Format Cells, Font, Bold, etc...)  They should stay the same throughout the useful life of the spreadsheet.  

(The data is used recursively, and it may jam up if you delete rows.)  

-Al Gerheim, K1QN

HP-49G+ Software Page:
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