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    "The complete on-board celestial navigator" by Bennett
    From: R Callum
    Date: 2009 Nov 1, 17:17 -0800

    I have used this book extensively and find a number of shortcomings.
    
    The table lookup process is error prone and slow due to top/bottom access to 
    the tables, the unnecessary combination of the Lat Dec with the sum res table 
    and the total absence of any indexing mechanism. I have resolved this by 
    recreating and reprinting the tables. I use a separate Lat Dec Table, 6 pages 
    tab indexed by degrees a double facing page covering 30 degrees. The sum res 
    table is extended to 12 pages each double page covering 15 degrees and is tab 
    indexed by degree sum and res making getting to the right page instantly a 
    snap. The remaining 6 pages cover LHA 90 to 180 indexed by degrees. All of 
    these are double facing pages giving the maximum coverage on one opening. I 
    have eliminated bottom access with two additional computation steps, if LHA 
    is greater than 180 then tableLHA=359.60-LHA and by finaly extracting Z from 
    the top of the res table alt=89.60-Z. Despite the additional steps I have 
    found this is MUCH faster and less stressful to use despite an extra 4 pages 
    of tables.
    
    As has been already discussed the inclusion of several different methods of 
    azimuth determination is confusing to the novice. My personal preference is 
    for Weir diagrams. The result is unambiguous and can be transfered directly 
    from diagram to plotting sheet using a Bretton plotter. The diagrams provide 
    in the book are not big enough or detailed enough although the idea of 
    splitting them into four separate diagrams is a good one. 
    
    Despite these problems the book is a good minimalist solution to get you home 
    astronav. It could be much improved by the suggestions above even if we had 
    to cut out the tabs ourselves. Please International Marine for the 2011-2015 
    edition.
    
    
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