Clutter filtering approaches
The following table shows how each major mode implements clutter filtering.
| Mode | Clutter filtering |
|---|---|
| FFT Major Mode | Uses frequency domain clutter filters, including GMAP. The power spectra are restored by interpolating across the gap of removed spectral points. |
| PPP Mode |
In this mode, RVP10 performs a DFT/FFT into the frequency domain just for clutter filtering, such as GMAP. In dual-polarization, the same spectral points that were removed and interpolated in the co-polar realm are treated the same in the cross-polar realm. After removal of ground clutter, the RVP10 inverts back to the time domain for moment computations. |
| Random Phase Mode | Uses frequency domain clutter filters, including GMAP. The power spectra are restored by interpolating across the gap of removed spectral points. |
| Batch Mode | Uses a simple DC removal for the small batch clutter filter. The high PRF large batch is then processed using frequency domain clutter filters, including GMAP. The power spectra are restored by interpolating across the gap of removed spectral points. |
RVP10 enables time-domain IIR clutter filtering techniques. However, Vaisala does not recommend using these techniques, as the IIR filter has several drawbacks:
Instead of IIR clutter filtering Vaisala recommends using other filtering techniques. The frequency domain filters available in RVP10 are configured using the mf setup command (See Mf — Clutter filters):
- Type 0: Fixed width filters with interpolation
- Type 1: Variable width single slope adaptive processing
- Type 2: Reserved for future development
- Type 3: GMAP