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    Re: Simplified Bris Sextant (calibration)
    From: Greg Rudzinski
    Date: 2012 May 14, 19:30 -0700

    A post calibration trial was made this afternoon for the Simplified Bris Sextant. No camera or magnification used. Just the Mark 1 eyeball through polarizing filters. The Sun's image was rocked to the low point then timed with center on the horizon.

    5/15/2012 UT 01:19:08 Hs 17* 23.7' Lat. 34* 9.6' N Lon. 119* 13.7' W Temp 68* F Press. 1016 mb

    Intercept 2.4' away
    Azimuth 281.5*

    This is a satisfactory trial result for a first effort with a proto type. It might also be time to rename the device from Bris to Fixed Altitude Reflector (FAR).

    Greg Rudzinski

    [NavList] Re: Simplified Bris Sextant (calibration)
    From: Greg Rudzinski
    Date: 12 May 2012 10:10

    Here is complete calibration data for 8 digital camera images taken through the Simple Bris Sextant as the horizon was observed passing just under the the center of the Sun. ( 1 pixel = 0.38')

    Lat. 34* 9.8' N Lon. 119* 13.8' W H.E. 8.5 ft.
    UT Date 5/12/2012
    UT 01:17:26 Hs 17* 24.9' corr. (-1.5' for 4 pixels) 17* 23.4' calibrated altitude
    01:17:23 17* 25.5' (-1.9' for 5 pixels) 17* 23.4'
    01:17:21 17* 25.9' (-2.3' for 6 pixels) 17* 23.6'
    01:17:18 17* 26.5' (-2.3' for 6 pixels) 17* 24.2'
    01:17:16 17* 26.9' (-2.7' for 7 pixels) 17* 24.2'
    01:17:13 17* 27.5' (-3.8' for10pixels) 17* 23.7'
    01:17:11 17* 27.9' (-4.2' for11pixels) 17* 23.7'
    01:17:09 17* 28.3' (-4.6' for12pixels) 17* 23.7'

    Avg. 17* 23.7' calibration altitude
    Spread 0.8'

    I am satisfied with these results and will be using this calibration value for future observations made with the Simple Bris Sextant.

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