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    Re: Digital Image CN Exercise #3
    From: Marcel Tschudin
    Date: 2010 Apr 11, 13:07 +0300

    Greg,
    
    Thank you for this exercise. I had in mind to ask you for one with the
    sun at a high altitude in order to see what can be achieved with more
    predictable refraction.
    
    Proceeding with your data, I get the following coordinates for the photographer:
    Using LL:
    34.194933 N, -119.246715 (W)
    Using UL:
    34.195451 N, -119.246592 (W)
    I proceeded then with the mean of the two locations, with an
    Azimuth Sun = 36.77653 (counted from South)
    However, looking at the NOAA chart doesn't show a light house in this
    area. (Or, did I miss it?) I proceeded then with the island. The cliff
    and the lowest edge of Anacapa Island is 0.9059375 deg further in West
    direction, having an azimuth of 37.6824675 deg (from South).
    A line in this direction crosses the West Anacapa Island. This would
    mean that the Middle and East Islands would be hidden behind the
    horizon; this however would mean that the height of the hidden islands
    wouldn't exceed about 30m (about 100ft). Looking at them with Google
    Earth gives me the impression that they are likely to be higher. As a
    check I drew a parallel line from the eastern etch of the Anapaca
    Islands and this passes close to your assumed location. So, what went
    wrong? In the mean time I did indeed do some modifications to the
    program but the checks I performed indicated that it seemed to work
    again correct. If the information of my program is correct you changed
    in CA to summer time on 4 April. Could it be that you missed this when
    converting local time to UTC?
    
    I attach a screen shot showing your assumed location as "Pt LL 0", the
    mean location as "Loc mean" and the mentioned azimuth lines to the
    Anacapa Islands.
    
    Marcel
    
    

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