Time measurements

I have borrowed the 'running time clock' of Rolf Apitsch to perform measurements on the time stamping accuracy of different cameras. See Rolf's web page on his experiments here. I used the following setup:

The control box and display built by Rolf receive a time synchronisation pulse via GPS. The display contains three rows with LEDs: The first row lights up one LED every 0.1 second, the second one every 0.01 s, the third one every 0.001 s. If the camera has an analog video signal, the control box inserts a time visualisation in the video signal. For normal CCD cameras, the time stamping accuracy of the readout software can be checked by comparing the running lights with the time stamp by the readout software. The latter reads the PC clock, which in turn is synchronized via the internet using the freeware TimeMemo.

For the analog cameras, the PAL signal was converted to USB by a converter from Conrad Electronics.

Here are the results for the different cameras (click the camera name for more details):

StellaCam3 (= Watec 120N+ with peltier cooler) - the time delay of 40 ms between the image acquisition and the time stamp of the video time inserter as measured by Gerhard Dangl was confirmed.
Mintron - basically no time delay was found
SkyNyx 2-0M - the acquisition software (Lucam Recorder) produced a time stamp ca. 200 ms after the actual acquisition

Thanks to Rolf for loaning his 'running light clock' - I call it 'Rolf's time machine'....

Detlef, 26 Aug 2008 - undated 29 Aug 2008.

Created by dvk, 26 Aug 2008.
Return to Koschny's Astronomy.