Wideband Observing
The wideband observing setup provides the widest possible bandwidth for a given observing band, with channel spacing depending on the number of polarization products.
| Wideband & Subarray Correlator Options | |
|---|---|
| Polarization products | Channel spacing |
| Full (RR, RL, LR, LL) | 2 MHz |
| Dual (RR, LL) | 1 MHz |
| Single (RR or LL) | 0.5 MHz |
For the low-frequency bands (L, S, C, X, and Ku bands) this uses the 8-bit samplers to provide a total of 2 GHz of bandwidth per polarization. The three highest-frequency bands (K, Ka, and Q bands) employ the new 3-bit (wideband) samplers, providing a total of 8 GHz of bandwidth; in this case all subbands are 128 MHz wide. In many frequency bands the total processed bandwidth is less than that delivered by the front-end. In those cases the observer may independently tune two 1 GHz baseband pairs when using the 8-bit samplers, or four 2 GHz baseband pairs when using the 3-bit samplers. The (fairly mild) tuning restrictions are described in the section on VLA Frequency Bands and Tunability.
