Projectile Spin Estimation via Radial Velocity Variation Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining the spin of a projectile using radar transceivers are not refined enough, leading to potential inaccuracies in spin rate measurement due to measurement noise and errors.
Innovation Solution
A method involving a radar transceiver that obtains a time series of radial velocity observations, calculates a center velocity, extracts a second time series of variations around the center velocity, estimates the frequency of this variation, and determines the spin based on the frequency, potentially using multiple time intervals and statistical methods for improved reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single frequency estimate is used from the second time series, then the calculation is simple, but the measurement reliability is reduced due to noise and errors
Solution Approach 1:
The second time series is divided into multiple time intervals, and the frequency is estimated separately for each interval. This segmentation allows the system to process the signal in manageable portions and reduces the impact of noise and errors in any single interval, thereby improving overall measurement reliability without significantly increasing computational complexity.
Solution Approach 2:
The system performs preliminary processing by dividing the time series into intervals and estimating frequencies for each interval before combining the results. This preliminary action prepares the data in a way that reduces noise and errors, leading to more reliable final spin measurements.
2Device complexity
If the time interval between observations is large, then the data processing is simpler, but the spin rate measurement accuracy is reduced
Solution Approach 1:
The system dynamically adjusts the time interval between observations based on the expected spin rate of the projectile. By optimizing the observation interval to capture at least two observations per rotation, the system maintains measurement accuracy while managing processing complexity. This dynamic adjustment ensures that the sampling rate is sufficient to accurately represent the spin characteristics without requiring excessive data points.
3Reliability
If multiple time intervals are used to estimate frequency, then the spin measurement reliability is improved, but the calculation time increases
Solution Approach 1:
The time series is segmented into multiple intervals, and frequency estimates are calculated for each interval in parallel or sequential manner. This segmentation enables the system to process the data in manageable chunks, improving reliability through multiple estimates while controlling calculation time through efficient processing of each interval.
Solution Approach 2:
The system uses the frequency estimates from multiple time intervals to refine the final spin measurement. By analyzing the distribution of frequency estimates and applying statistical methods, the system obtains a more reliable spin value while managing calculation time through efficient aggregation and processing of the multiple estimates.
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 provides a more reliable estimation of the spin rate by capturing periodic variations in radial velocity, reducing the impact of measurement noise and errors, and allowing for accurate spin determination even at high spin rates.
Implementation Method 1
obtaining from a radar transceiver a first time series comprising observations of a radial velocity of the projectile relative to the radar transceiver
Implementation Method 2
The variation in the first time series around the center velocity of the projectile is caused by reflections of the radar signal from features of the projectile, as said features rotate towards or away from the radar due to the spin
Data Source
AI summary
A method for estimating a spin of a projectile, the method comprising obtaining a first data series representing a radial velocity of a projectile over time in accordance with a radar signal reflected from the projectile, subtracting a center velocity of the first data series from the first data series to form a second data series representing a variation of the radial velocity of the projectile around the center velocity over time, dividing the second data series into respective time intervals, estimating, for each of the time intervals of the second data series, a frequency of the variation of the radial velocity of the projectile around the center velocity, and determining a spin of the projectile based on the estimated frequencies of the variation of the radial velocity of the projectile.