Data Acquisition

Data Input :
The analog input from the photometers is read by an MSI-4000 4-channel, 12-bit, isolated analog input card. The dedicated PEP data acquisition computer is a 400 MHz Compaq running DOS 6.22. The data acquisition programs are written in Q-Basic 4.5. The data are initially stored on a RAM disk, and at the end of the data run are transferred to the hard disk. At the start of the data run, the computer clock is synchronized with the Ultralink 325 WWVB receiver through a serial port.

The analog input (AI) program for occultations stores the time and 1000 data points per second, to achieve 1 ms. resolution.

Variable Star Observations:
The AI program for photometric variable observations with the PPI photometer averages readings for 10 seconds, and records the time and the average. This produces data consistent with the format of the Optec SSP-5 photometer.

Remote Planets Photometry:
The photometry program for remote planets records five readings, their average, and the time for each of the readings. This process is repeated to record data for the sky, comparison star, planet, and check star.

Click here to see a remote planet data run

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