Correction to "Cumulative probability of detection for targets approaching a uniformly scanning search radar"

1964 ◽  
Vol 52 (6) ◽  
pp. 708-709 ◽  
Author(s):  
J.D. Mallett ◽  
L.E. Brennan
Keyword(s):  
Probability Of Detection ◽  
Cumulative Probability

scholarly journals Multiple Step Interlaced Beam Scan to Minimize the Deviation of Radar Detection Performance

2020 ◽  
Vol 20 (2) ◽  
pp. 125-130
Author(s):  
Ji Hwan Yoon ◽  
Yeonhee Park ◽  
Ji Eun Roh ◽  
Sung Chul Park
Keyword(s):  
Figure Of Merit ◽  
Detection Performance ◽  
Probability Of Detection ◽  
Line Of Sight ◽  
Cumulative Probability ◽  
Search Volume ◽  
Optimal Values ◽  
Fixed Beam ◽  
Beam Lattice ◽  
Multiple Step

For detection of targets, a radar conventionally scans a specified search volume with a fixed beam lattice of a specified beam spacing. With the fixed beam lattice, the detection performance of the radar within a unit beam lattice changes depending on the line-of-sight angle to a target. In this paper, multiple step interlaced scan is proposed to minimize the deviation of the detection performance due to the change of the target line-of-sight angle. As a figure of merit for the detection performance, the cumulative probability of detection is analyzed for various values of the interlaced scan step with different beam overlap ratios, and the optimal values of the steps to minimize the deviation of the cumulative probability of detection are derived.

Impact of Multiple On-Board Inspections on Cumulative Probability of Detection

2005 ◽  
Author(s):  
Brian D. Shook ◽  
Harry R. Millwater ◽  
Michael P. Enright ◽  
Stephen J. Hudak ◽  
William L. Francis
Keyword(s):  
Correlation Coefficient ◽  
Critical Issue ◽  
Step Function ◽  
Probability Of Detection ◽  
Cumulative Probability ◽  
Test Case ◽  
Dramatic Improvement ◽  
Material Defects ◽  
Significant Difference ◽  
Stress Spectrum

The impending application of on-board sensors for detecting and sizing material defects and evaluating their consequences will lead to improved forecasting of readiness, as well as improved safety, retirement-for-cause, and management of assets. This research looks at the consequences of multiple, i.e., continual, on-board inspections on the cumulative probability of detection (CPOD) of the system; that is the probability of detecting a defect considering all previous inspections. In particular, modeling and simulation of the CPOD is examined as a function of the degree of correlation between subsequent inspections. A surface crack in a turbine disk is used as a test case with loading from a typical stress spectrum from a fighter engine. The analysis indicates that a significant difference in detectability is achieved through multiple inspections depending upon the degree of correlation between inspections, with statistically independent inspections exhibiting a “dramatically” improved CPOD over dependent inspections. In particular, if each inspection is statistically independent 1) it is the left tail of the parent POD that defines the CPOD, 2) for the same median value, a higher coefficient of variation of the parent POD generates a significantly more effective CPOD, and 3) if enough inspections are performed, the CPOD curve becomes a step function at the first non-zero value in the parent POD curve, thereby giving orders-of-magnitude improvement in detectibility over the parent POD. The critical issue of statistical independence of multiple inspections is investigated by examining the CPOD as a function of correlation between inspections. The results indicate that the effectiveness of continual inspections on the CPOD varies from a correlation coefficient of zero (independent), which gives a dramatic improvement compared to the parent POD, to a correlation coefficient of one (dependent), which reverts to the parent POD. In summary, the correlation between inspections is a critical component that determines the effectiveness of continual inspections.

Cumulative Detection Probability as a Basis for Pressure Vessel Inspection Intervals

1995 ◽  
Vol 117 (4) ◽  
pp. 399-403 ◽  
Author(s):  
G. Garic
Keyword(s):  
Fracture Mechanics ◽  
Pressure Vessel ◽  
Detection Probability ◽  
Flaw Detection ◽  
Probability Of Detection ◽  
Acceptable Level ◽  
Cumulative Probability ◽  
Failure Risk ◽  
Flaw Detection Probability

This work discusses use of the cumulative flaw detection probability as the basis for establishing pressure vessel inspection intervals. The method is based on the accumulated probability of detecting a flaw over several inspections. It explicitly incorporates a user decision as to the acceptable level of failure risk. A four-step approach is outlined including fracture mechanics flaw growth calculations with probabilistic treatment of detection probability. It is concluded that (a) inspection intervals based on the cumulative probability of detection provide significant advantages over traditional cycle-based methods, (b) pressure vessel recertification inspections should rely on high percentage inspections conducted on a relatively infrequent basis.

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