Estimating weather and ground reflectivity with doppler spectral information

• US 10,048,370 B2
• Filed: 07/07/2015
• Issued: 08/14/2018
• Est. Priority Date: 07/07/2015
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Christianson, Paul E., Jensen, Robert J.
• Primary Examiner(s): Bythrow, Peter M
• Application Number:
  US14/793,546
• Publication Number:
  US 20170010355A1
• Time in Patent Office: 1,134 Days
• Field of Search: 342 26 R
• CPC Class Codes: G01S 13/5244 Adaptive clutter cancellation specially adapted for airborne MTI, G01S13/5242
• CPC Class Codes: G01S 13/953 mounted on aircraft
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Systems, methods, and devices for processing a radar return signal to estimate reflectivity values. An example weather radar system includes one or more antennas configured to transmit a radar signal generated by a transmitter and deliver a radar return signal to a receiver. The example weather radar system further includes one or more processors configured to sample the radar return signal, determine a first signal power measurement of the sampled radar return signal based on Doppler signal processing, determine a quality of the first signal power measurement, and estimate reflectivity values of the sampled radar return signal based on the first signal power measurement when the quality is above a threshold. The example weather radar system further includes memory configured to store the estimated reflectivity values.

Claims

1. A weather radar system comprising:

one or more antennas, wherein the one or more antennas are configured to;

transmit a radar signal generated by a transmitter; and

deliver a radar return signal of the transmitted radar signal to a receiver;

and

one or more processors configured to;

sample the radar return signal at a periodic sample rate, wherein timing of the periodic sample rate following transmission of the radar signal corresponds to a range bin;

determine a first signal power measurement of the sampled radar return signal of the first range bin based on Doppler signal processing, wherein the first signal power measurement comprises at least one of a ground signal power component or a weather signal power component;

determine a quality of the first signal power measurement;

responsive to determining that the quality of the first signal power measurement is above a threshold, estimate reflectivity values of the sampled radar return signal of the first range bin based on the first signal power measurement; and

responsive to determining that the quality of the first signal power measurement is below the threshold;

determine a second signal power measurement of the sampled radar return signal of the first range bin based on non-Doppler signal processing; and

estimate reflectivity values of the sampled radar return signal of the first range bin based on the second signal power measurement; and

memory, wherein the memory is configured to store the estimated reflectivity values.

2. The weather radar system of claim 1, wherein the one or more processors are configured to estimate reflectivity values of the sampled radar return signal by at least being configured to separately estimate the ground reflectivity values based on the ground signal power component and weather reflectivity values based on the weather signal power component.

3. The weather radar system of claim 1, wherein the memory is configured to store a data structure, wherein the data structure comprises a three-dimensional (3-D) volumetric buffer defining a distribution of reflectivities, and wherein the one or more processors are further configured to update a portion of the data structure with the estimated reflectivity values.

4. The weather radar system of claim 3, wherein the one or more processors are configured to update the portion of the data structure with the estimated reflectivity values by at least being configured to update the portion of the data structure with at least one of estimated ground reflectivity values or estimated weather reflectivity values.

5. The weather radar system of claim 1, wherein the memory is configured to store a data structure, wherein the data structure comprises a three-dimensional (3-D) volumetric buffer defining a distribution of reflectivities, and wherein the one or more processors are further configured to update a portion of the data structure with the estimated reflectivity values based on the second signal power measurement.

6. The weather radar system of claim 1, wherein the one or more processors are configured to determine the quality of the first signal power measurement by at least being configured to determine whether the sampled radar return signal of the first range bin is at least partially eclipsed.

7. The weather radar system of claim 1, wherein the one or more processors are configured to determine the quality of the first signal power measurement by at least being configured to determine amount of multiple-time-around echo (MTAE) contamination associated with the sampled radar return signal of the first range bin.

8. The weather radar system of claim 1, wherein the one or more processors are configured to determine the first signal power measurement based on Doppler signal processing by at least being configured to measure at least one of:

ground signal power,

weather signal power,

receiver noise power, or

MTAE power.

9. The weather radar system of claim 1, wherein the one or more processors are configured to determine the second signal power measurement of the sampled radar return signal of the first range bin based on non-Doppler signal processing by at least being configured to measure the sum of ground signal power, weather signal power, and receiver noise power of the sampled radar return signal of the first range bin.

10. A method comprising:

transmitting, by one or more antennas, a plurality of radar signals generated by a transmitter;

delivering, by the one or more antennas, a plurality of radar return signals of the transmitted radar signals to a receiver;

sampling, by one or more processors, plurality of radar return signals at a periodic sample rate to generate a first sampled radar return signal and a second sampled radar return signal, wherein timing of the periodic sample rate following transmission of the plurality of radar signals corresponds to a range bin;

determining, by the one or more processors, a first signal power measurement of the first sampled radar return signal of a first range bin based on Doppler signal processing, wherein the first signal power measurement of the first sampled radar return signal comprises at least one of a ground signal power component or a weather signal power component;

determining, by the one or more processors, a quality of the first signal power measurement of the first sampled radar return signal;

responsive to determining that the quality of the first signal power measurement of the first sampled radar return signal is above a threshold, estimating, by the one or more processors, reflectivity values of the first sampled radar return signal of the first range bin based on the first signal power measurement;

determining, by the one or more processors, a first signal power measurement of the second sampled radar return signal of the first range bin based on Doppler signal processing;

determining, by the one or more processors, a quality of the first signal power measurement of the second sampled radar return signal; and

responsive to determining that the quality of the first signal power measurement of the second sampled radar return signal is below the threshold;

determine a second signal power measurement of the second sampled radar return signal of the first range bin based on non-Doppler signal processing; and

estimating, by the one or more processors, reflectivity values of the second sampled radar return signal based on the second signal power measurement.

11. The method of claim 10, wherein estimating reflectivity values of the first sampled radar return signal comprises separately estimating, by the one or more processors, ground reflectivity values based on the ground signal power component and weather reflectivity values based on the weather signal power component.

12. The method of claim 10, further comprising updating, by the one or more processors, a portion of a data structure stored in memory with the estimated reflectivity values of the first sampled radar return signal, wherein the data structure comprises a three-dimensional (3-D) volumetric buffer, and wherein the 3-D volumetric buffer defines a distribution of reflectivities.

13. The method of claim 12, wherein updating the portion of the data structure stored in memory with the estimated reflectivity values of the first sampled radar return signal comprises updating, by the one or more processors, the portion of the data structure with at least one of estimated ground reflectivity values or estimated weather reflectivity values.

14. The method of claim 10, further comprising updating, by the one or more processors, a portion of a data structure stored in memory with the estimated reflectivity values based on the second signal power measurement of the second sampled radar return signal, wherein the data structure comprises a three-dimensional (3-D) volumetric buffer, and wherein the 3-D volumetric buffer defines a distribution of reflectivities.

15. The method of claim 10, wherein determining the quality of the first signal power measurement of the first sampled radar return signal comprises determining, by the one or more processors, whether the sampled radar return signal of the first range bin is at least partially eclipsed.

16. The method of claim 10, wherein determining the quality of the first signal power measurement of the first sampled radar return signal comprises determining, by the one or more processors, an amount of multiple-time-around echo (MTAE) contamination associated with the sampled radar return signal of the first range bin.

17. A non-transitory computer-readable medium storing instructions that when executed by one or more processors cause the one or more processors to:

sample a radar return signal at a periodic sample rate, wherein timing of the periodic sample rate following transmission of the radar signal corresponds to a range bin;

determine a first signal power measurement of the sampled radar return signal of the first range bin based on Doppler signal processing, wherein the first signal power measurement comprises at least one of a ground signal power component or a weather signal power component;

determine a quality of the first signal power measurement;

responsive to determining that the quality of the first signal power measurement is above a threshold, estimate reflectivity values of the sampled radar return signal of the first range bin based on the first signal power measurement; and

responsive to determining that the quality of the first signal power measurement is below the threshold;

determine a second signal power measurement of the sampled radar return signal of the first range bin based on non-Doppler signal processing; and

estimate reflectivity values of the sampled radar return signal of the first range bin based on the second signal power measurement.

18. The non-transitory computer-readable medium of claim 17, storing further instructions that when executed cause the one or more processors to:

update a portion of a data structure stored in memory with the estimated reflectivity values.