Case 2 Calculation of polarization measurands

The processing is done by pulse pair mode. However, both FFT and random phase processing can be performed only if Z_dr and standard moments are requested for output. In any mode, you may select a clutter filter.

RVP10 calculates the polarization parameters as follows:

Z D R = 10 L O G [\frac{S_{h h}}{S_{v v}}]

Z D R = 10 L O G [\frac{< {| S_{h h} |}^{2} > - N_{h}}{< {| S_{v v} |}^{2} > - N_{v}}] + G D R

R H O H V = | ρ_{h v} (0) |

P H I D P = \arg [ρ_{h v} (0)]

Where the following definitions are used:


Transmit horizontal	or	Transmit vertical
$g_{h}^{r} g_{h}^{t} S_{h h} = < {\| S_{h h} \|}^{2} > - N_{h}$	or	$g_{v}^{r} g_{v}^{t} S_{v v} = < {\| S_{v v} \|}^{2} > - N_{v}$

The noise powers within the 2 channels are denoted as N_h and N_v. The noise corrections to S_hh and S_vv are optionally configured in the TTY setups. The Z_dr Offset is the total (transmit and receive) differential channel gain. It must be calibrated for the system as follows:

dB value is: $Z D R O f f s e t = 10 L O G o f f s e t$ where the linear value is $o f f s e t = \frac{g_{v}^{r} g_{v}^{t}}{g_{h}^{r} g_{h}^{t}}$ .

The correlation function is computed as follows:

ρ_{h v} (0) = \frac{< S_{v h} S_{h h}^{*} >}{\sqrt{S_{h h} S_{v v}}}

The gain terms cancel in the calculation of ρ, so in the implementation they are assumed to be =1.