Polarisation

Polarisation displays provide useful diagnostic tools. The noise diode injects a linearly polarised signal at 45° to the probes. Each probe therefore receives equal noise power. You can look at the polarisation display consisting of the cross-power spectrum between the two polarisation IF chains from a single antenna. This display will tell you if both IF chains are operating normally for that antenna. The plot should be similar to this one except that the baseline (BL) will be set for an autocorrelation (e.g., 11 or 44) and the polarisation (PO) will be AB for frequency 1 and CD for frequency 2.