Frequency Accuracy

As the key to digging the pulsar signal out of the noise is to accurately synchronously average the pulse signal over a period of time (typically an hour or so), the accuracy of the data sampling timing must be high. As a general guide, timing accuracies of better than 1 ms over the observation time is required. For an observation time of 1 hour this translates to better than 0.1 ppm stability for the data sampling timing. Using a soundcard, for example, with the large variations in quality between models, without modification with a more accurate clock, is not recommended.

Usually data is recorded and then processed "off-air" by software. As the actual observed period of the pulse is the intrinsic pulsar signal period modified by doppler effects due the observer's moving point of reference in space (Earth's orbit around the Sun and rotation on its own axis), some sort of search mechanism is required in the "off-air" software. A number of test synchronous integrations will need to be done to find the best integration period (which produces the best S/N).