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    Question about Pub 249 combined Star and Planet sight reduction
    From: Rod Deyo
    Date: 2000 Nov 16, 8:49 PM

    I have the following navigation problem. Suppose I have taken sights for two 
    planets and three stars well chosen from Pub. 249 Vol 1. Each of the two 
    planet's GHA and declination are found from the Nautical Almanac and Hc found 
    from the corresponding AP and LHA using Pub. 249 Vols 2 or 3 (or perhaps Pub 
    229). LOPs are then plotted for each planet. Next, the three star Hc obtained 
    directly from Pub. 249 Vol 1 and LOPs are plotted (again, advanced, if 
    needed, to the common time). But I should now correct the Pub. 249 star fix 
    (or, equivalently, the APs or LOPS) using Vol 1 Table 5 corrections for 
    procession and nutation for the appropriate year and LHA. Ntoe that I do not 
    need to do this for the planets since that information has already been 
    incorporated into the Almanac data. Suppose I choose to correct the star fix. 
    This gives me a single fix from the three star sights, but no easy way to do 
    least square fit or other unbiased average simultaneously against the planet 
    LOPs as well. My question - is there a way to properly weigh the single, 
    corrected star fix against the individual planet LOPs? Alternatively, I could 
    have gone ahead and adjusted each individual star AP (or LOP) for the 
    procession and nutation correction and then found the overall least square 
    fit among all five star and planet LOPs to determine the final fix 
    (equivalent to using tha Almanac, GHA Aries, and Pub. 229 for each star). But 
    is there an easier way, more in the spirit of Pub. 249?
    
    Thanks!
    
    Rod Deyo
    
    

       
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