VLBA > Output Rate

# 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

$$R = 4 \cdot \frac{N_{\rm stn} \cdot (N_{\rm stn}+1) \cdot N_{\rm sbb} \cdot N_{\rm spc}}{T_{\rm int}}\cdot N_{\rm ppb} \cdot N_{\rm phc} \cdot p$$

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

$N_{\rm stn} , \; N_{\rm sbb} , \; N_{\rm spc}$ are the numbers of observing stations, data channels, and spectral points per data channel, respectively;

$T_{\rm int}$ is the correlator integration period;

$N_{\rm ppb}$ is the number of pulsar phase bins;  and

$N_{\rm phc}$ 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.