Online Viewing Program for Scintillation Data Files

A program has been developed to allow the on line examination of the scintillation data records. At this time, the actual number of files available for this purpose is limited to selected files. This does not constitute a real-time repository of recorded passes.

Data has been recorded from the 149.988 MHz emanations of the Transit satellites. Amplitude scintillations have been recorded using a 70 Hz sampling rate by a Vanguard receiver connected to a computer, via a PC30B interface board (see diagram). Records are read and processed by a C program written for the task and the value of 1 in every 5 data elements is plotted in a pbm image. The ppmtogif segment of the PBMPLUS package that interfaces with gnuplot is used to display an image supported by most web browsers. The vertical scale of the image is in 4mv per bit units.

The process enacted consists of the following steps:

* note that time marks have been added by a signal generator and these are removed for clarity in the record. Filtering is useful in removing trends in the signal strength to view the scintillation behaviour more clearly. In this instance, a moving average high-pass filter with a 0.2 Hz cutt-off was incorporated in the data cleaning process.

Please understand that this process happens in response to user requests, not from stored images and so may take some time.

Date, time and place when data was recorded

Time period of data

Choose data processing option

Raw data Time marks removed Time marks removed and filtered

Page accessed times since 10/3/1998.