pyart.util.estimate_noise_ivic13#

pyart.util.estimate_noise_ivic13(pwr_w_ray, pct=3.270436, delay=2, flat_reg_wlen=32, flat_reg_var_max=0.439551, snr_thr=1.769572, npulses=30, ngates_min=800, ngates_final_min=200, ngates_median=10, iterations=10, get_noise_pos=False)[source]#

Estimate noise parameters of a ray

Use the method of estimating the noise level in a ray outlined by Ivic, 2013.

Parameters:

  • pwr_w_ray (array like) – Doppler spectrum in linear units.

  • pct (float) – Point Clutter Threshold

  • delay (int) – distance of the gate to which compare for point target threshold

  • flat_reg_wlen (int) – Minimum number of gates that should contain a valid region. Default gives a size of 8 km with 83.3 m resolution

  • flat_reg_var_max (float) – Maximum local variance of powers in decibels to consider the region as flat.

  • snr_thr (float) – Threshold applied in steps 3 and 6

  • npulses (int) – Number of pulses used to compute the power of the array

  • ngates_min (int) – minimum number of gates with noise to consider the retrieval valid

  • ngates_final_min (int) – minimum number of gates that have to be left after the last step to consider the retrieval valid

  • ngates_median (int) – number of consecutive gates above the median power that would result in them considered signal and removed

  • iterations (int) – number of iterations in step 7

  • get_noise_pos (bool) – If True the indices of the gates identified as noise will be returned

Returns:

  • mean (float-like) – Mean of the gates in the ray identified as noise.

  • var (float-like) – Variance of the gates in the ray identified as noise.

  • nnoise (int) – Number of noise gates in the ray.

  • inds_ray (1D-array) – The indices of the gates containing noise

References

I.R. Ivic, C. Curtis and S.M. Torres, Radial-Based Noise Power Estimation for Weather Radars. Journal of Atmospheric and Oceanic Technology, 2013, 30, 2737-2753.