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Author
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Topic: Star Pilot Problems
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sholekamp
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posted March 25, 2012 08:15 AM
I am new to the Star Pilot software. I have completed the Starpath celestial course and am using problems from the book to learn to use the Star Pilot. I am having trouble getting answers to compare. example - Comparing the answers from problem 9.4a, the book answer is a = 25.3 T and Zn = 205. When I plug in the figures from the problem into Star Pilot, I get In(nm) = 48.10 and Zn 205.3. I am assuming that "a" should be very close to "In(nm)," correct? Any idea where I am going wrong?
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Capt Steve Miller
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posted March 25, 2012 08:53 AM
I suspect that you used the given DR position. When using the SP program to compare its results with the book (manual using tables) results you must use the same parameters. This means using the Latitude you use when entering the tables, in this example using 45° N NOT the DR Latitude 44°58' and using the Assumed Longitude 122° 04.5'W instead of the given DR Longitude of 122° 24' W. When using those parameters I got an 'a' of 25.0 and a Zn of 205.8°T
From: Starpath
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sholekamp
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posted March 26, 2012 06:49 AM
I tried to uses those figures and got In(nm)= 55.80 and Zn = 25.08.. Here is what I did. In the "Edit" tab I clicked "settings" and entered Date = 7-26-1978; DR Lat = 45.000; DR Lon = 122.046; IC(min) =0'; HE = 16; Limb = Lower. Under the Advanced tab I changed the UT Offsets - ZD: = 7.000; and WE: = -13. Then under the "Sight Reduction" tab, I entered "Moon" ; Watch time: = 07-50-07; and Hs: = 51.252. Any thoughts as to what I did wrong? I appreciate your quick response on the previous question.
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David Burch
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posted March 26, 2012 12:10 PM
could you please try this again, but when posting make a list of each step of what you actually typed in and what you saw on the screen at each step, and then carry on to show what answer you got.
ie start from the main menu listing 7 options, then ie
3 sight reduction
3 moon
then list all the input, step by step... that way we can work though it here.
From: Starpath, Seattle, WA
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David Burch
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posted March 26, 2012 12:16 PM
the other note, it is important to first work thought the moon examples, or whatever you are working on from the instruction manual. So please confirm first that you have duplicated the examples in the manual.
From: Starpath, Seattle, WA
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sholekamp
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posted March 26, 2012 01:57 PM
I figured out what I did wrong. I was using the Lower Limb of the moon rather than the Upper Limb.
However, I don't understand the use of the assumed Lat/Lon. Do I have to calculate that somehow? In other words, do I have to go through the calculations similar those described on in "Step 4 = Choosing the Assumed Position" on page 63 of the home study course?
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Capt Steve Miller
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posted March 26, 2012 03:51 PM
When you are trying to compare reductions done from problems in the book by tables and doing those problems with the StarPilot program the simple answer is yes. Use the sight reduction by the tables to get the Assumed Long. and use the whole number Latitude for your assumed Lat. just as you do with the table sight reductions.
From: Starpath
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sholekamp
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posted March 27, 2012 08:20 AM
When taking sightings on the open waters, I would I would use the DR position that I have created from my log and DR calculations? Would I round off my Lat. position on the open water?
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Capt Steve Miller
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posted March 27, 2012 02:04 PM
The answer to your first question is YES. for the second question the answer is NO.
You would use your complete DR position and the 'a' and Zn will be from the DR to your actual LOP/s or fix. You would only round off the DR Lat and use the assumed Long when you are comparing table value data and the StarPilot data.
From: Starpath
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sholekamp
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posted March 27, 2012 07:00 PM
Thanks you very much for your help! steve
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