Changes between Version 4 and Version 5 of Sensors/Specim


Ignore:
Timestamp:
Dec 14, 2009 11:10:31 AM (9 years ago)
Author:
mggr
Comment:

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  • Sensors/Specim

    v4 v5  
    2121The data from the CCD is transferred to a framegrabber card in the computer using [http://en.wikipedia.org/wiki/Camera_Link Camera Link].  As this is a digital protocol, there are no digitisation effects to worry about.
    2222
    23 The frame grabber lag time is apparently 55ms regardless of frame rate (i.e. a frame is captured 55ms after the nav sync pulse).
     23== Timing ==
     24
     25Both Specim instruments are connected to a nav-sync box that timestamps the start of acquisition against GPS time.  This measures the time from the start of acquisition pulse to the next GPS pulse-per-second.
     26
     27The frame grabber lag time is apparently 55ms regardless of frame rate (i.e. a frame is captured 55ms before the nav sync pulse).
     28
     29Consequently the timing of a start of acquisition is `next_GPS_PPS - navsync_time - 55ms`. [mggr: check this isn't +55ms!]
    2430
    2531== Eagle ==