Output Rate

Correlation parameters should result in an output rate less than 10 MBytes per second (of observing time) for routine DiFX processing; higher rates may be considered if required and adequately justified. Observers should ensure that their data-analysis facilities can handle the dataset volumes that will result from the correlation parameters they specify.

An approximate parametrization of the output rate is given by

$$R=4\cdot \frac{N_{\mathrm{s}\mathrm{t}\mathrm{n}}\cdot (N_{\mathrm{s}\mathrm{t}\mathrm{n}}+1)\cdot N_{\mathrm{s}\mathrm{b}\mathrm{b}}\cdot N_{\mathrm{s}\mathrm{p}\mathrm{c}}}{T_{\mathrm{i}\mathrm{n}\mathrm{t}}}\cdot N_{\mathrm{p}\mathrm{h}\mathrm{c}}\cdot p$$

where the rate $R$ is in Byte/s;

$N_{\mathrm{s}\mathrm{t}\mathrm{n}},N_{\mathrm{s}\mathrm{b}\mathrm{b}},N_{\mathrm{s}\mathrm{p}\mathrm{c}}$ are the numbers of observing stations, data channels, and spectral points per data channel, respectively;

$T_{\mathrm{i}\mathrm{n}\mathrm{t}}$ is the correlator integration period;   and

$N_{\mathrm{p}\mathrm{h}\mathrm{c}}$ is the number of phase centers.

The polarization factor $p=1$ for single-polar, or dual-polar parallel-hand output;  or $p=2$ for cross-polar, four-Stokes processing.

Output data rates are also estimated by SCHED.