Variable Integration Time Doppler Filter Bank
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radar systems have limited Doppler resolution for distinguishing between closely-located targets due to a fixed integration time for Doppler processing, which restricts the ability to accurately determine the velocity of slower targets within the same range resolution cell.
Innovation Solution
Implementing a method where the integration processing time for each Doppler filter varies inversely with its corresponding Doppler frequency, allowing longer processing times for lower Doppler frequencies and shorter times for higher frequencies, thereby enhancing Doppler resolution for all detected targets within a radar's observing volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed integration time is used for Doppler processing, then the radar can handle high-speed targets, but the Doppler resolution for slower targets is limited
Solution Approach 1:
The patent applies dynamics by making the integration time variable rather than fixed. The system dynamically adjusts the integration time based on the Doppler frequency of each filter, using longer integration times for lower Doppler frequencies (slower targets) and shorter integration times for higher Doppler frequencies (faster targets). This dynamic adaptation resolves the contradiction by allowing the radar to optimize measurement precision for different velocity ranges within the same system.
Solution Approach 2:
The patent changes the parameter of integration time from a fixed value to a variable parameter that depends on Doppler frequency. By implementing multiple filters with different integration times corresponding to different Doppler frequency ranges, the system achieves both high Doppler resolution for slow targets and maintains the ability to handle fast targets, thus resolving the technical contradiction between measurement precision and adaptability.
2Measurement precision
If the integration time is increased to improve Doppler resolution, then slower targets can be distinguished, but the processing time for all targets increases
Solution Approach 1:
The patent applies local quality by assigning different integration times to different Doppler frequency filters rather than using a uniform integration time for all targets. Each filter is optimized with an integration time appropriate for its specific Doppler frequency range, allowing the system to achieve high Doppler resolution for slow targets without unnecessarily increasing processing time for fast targets. This localized optimization resolves the contradiction between measurement precision and processing time.
Solution Approach 2:
The patent segments the Doppler processing into multiple frequency-dependent channels, each with its own optimized integration time. By dividing the Doppler spectrum into multiple bands and applying appropriate integration times to each segment, the system achieves high resolution where needed while maintaining efficient processing overall, thus resolving the contradiction between Doppler resolution and processing time.
3Measurement precision
If multiple filters with varying integration times are used, then Doppler resolution is enhanced, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing a filter bank where each filter serves a specific Doppler frequency range but all filters work together within a unified processing framework. The system achieves enhanced Doppler resolution across multiple velocity ranges using a single multi-functional filter bank structure, reducing the need for separate processing systems and thus mitigating the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables improved discrimination between targets moving at different velocities within the same range resolution cell, increasing Doppler resolution and enhancing the radar's ability to accurately determine radial velocities of both high and low-speed targets.
Implementation Method 1
radar devices detect and locate objects (i.e., targets), by transmitting electromagnetic signals that reflect off targets within a sensor's field-of-view
Implementation Method 2
The reflected signal returns to the radar as an echo
Implementation Method 3
The Doppler effect manifests itself when there is a relative range rate, or radial velocity, between the radar and the target. When the radar's transmit signal is reflected from such a target, the carrier frequency of the return signal will be shifted
Data Source
AI summary
A system and method are provided for processing echo signals reflected from one of more targets in a radar field-of-view. The method includes receiving echo signals reflected from one or more targets in the radar field-of-view in response to a sequence of transmit pulses; generating a received signal vector containing samples from the received echo signals; and applying the received signal vector to a set of filters configured to calculate a Doppler spectrum for a set of Doppler frequencies to which each filter is tuned, wherein an integration processing time for each filter varies relative to the Doppler frequency of each filter.