Standard moment calculations (T, Z, V, W)

Standard moments are available for each polarization case. Since there can be up to 4 channels of time series input, there are several choices for computing the standard moments. For example, in the STAR mode (see Case 2: Simultaneous Dual Transmit and Receive (STAR)), the standard moments are computed from:

  • Shh samples
  • Svv samples
  • Average of the results from the Shh and Svv samples
The reflectivity moment can be computed from the Shh, Svv, and Shv samples simultaneously in all 3 choices.

In Case 3: Alternating H/V Transmit: Single Receiver, the case is handled by averaging the individual channel correlations, and then using the average correlations in the standard moment processing. The averaging must take into account the differential gain of the channels.

The method to use is selected in the setup. There are 4 questions in the mp section:

T/Z/V/W computed from: H–Xmt:YES V–Xmt:YES

T/Z/V/W computed from: Co–Rcv:YES Cx–Rcv:NO

Given a choice between vertical and horizontal transmit, the first 2 questions specify which transmit polarization should be used.

When choosing:

  • H-Xmt:YES V-Xmt:NO logic, V and W are computed from the H-channel co-receiver
  • H-Xmt:NO V-Xmt:YES logic, V and W are computed from the V-channel co-receiver
  • H-Xmt:YES V-Xmt:YES logic, V and W are computed from the averaged correlations from both receivers
RVP10 can produce ZH, ZV, and ZHV with any logical selection.

For the fixed H or V case, where there is only one transmit polarization, this question does not apply. The processor uses samples for the polarization that is transmitted.

Given a choice between using the co- or cross-polar receivers, the second 2 questions are define which one should be used. This question applies only to systems that can measure LDR, (fixed or alternating transmit, dual-channel receiver systems).

The tables in Reflectivity calibration parameters summarize the standard moment calculations for each mode and how to configure the four TTY setup responses.

These are the only supported modes. Some combinations of responses are unsupported. For example, it is not supported to answer both Co-Rcv: NO and Cx-Rcv: NO.

Each table identifies the transmitter/receiver case and what samples are available. The notation HH signifies that the shh samples are available. The tables use "—" to indicate that either a YES or NO response causes the same result, RVP10 does not care what response is made. In cases where averaging is performed, the type of weighting used is indicated.