circular error


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circular error

[′sər·kyə·lər ′er·ər]
(ordnance)
A bombing error measured by the radial distance of a point of bomb impact, or mean point of impact, from the center of the target, excluding gross errors.
With an airburst atomic bomb, the bombing error measured from the point on the ground immediately below the bomb burst to the desired ground zero.

circular error (CE)

circular error (CE)click for a larger image
An accuracy figure representing the stated percentage of probability that any point expressed as a function of two linear components (e.g., horizontal position) will be within the given figure. Circular error probability (CEP 50%), and CE (90%) are used commonly. A horizontal measurement on the ground, in feet or meters, defining a radius of a circle, within which an object of known coordinates should be found on an image. The CE value should have some measure of probability (P) associated with it. For example, a CE of 100 m and .9 P, means that 90% of the time the object will fall within a circle having a radius of 100 m. Circular error is normally used in armament delivery results.
References in periodicals archive ?
Williams, "A Comparison of Circular Error Probable Estimators for Small Samples," DTIC Document, 1997.
Accuracy is measured by what is called CEP (Circular Error Probability), essentially the measured diameter of a circle in which 50 percent of rounds will impact.
And instead of hitting city blocks with ordnance we're hitting single vehicles, single buildings into four or five feet circular error averages.
Excalibur will be fired out to a range of 40 kilometers from the M777A1, and because of its Global Positioning System and inertial navigation guidance, will deliver precision-strike capability (less than 10 meters Circular Error of Probability) at all ranges.
TLE and WDE can be stated as circular error probable (CEP), as the story explains, which is a 50th percentile measurement.
Overall, terrain referenced navigation accuracies of 30 m circular error probability (horizontal) and 3 m linear error probability (vertical) are reported as being achievable over terrain rougnesses down to two per cent.
Accuracy was only a matter of personal pride (the traditional bets on first drop, best drop, and best Circular Error Probable [CEP] had been placed), but one day, Marines on the ground would depend on my proficiency.
The rockets are far from accurate, with a "circular error probability" of about half a mile at the limit of their range.
The "circular error probable' (CEP, the basic measure of bomb accuracy) of the FB111 was about three-quarters of a mile--better than anything achieved in World War II, but still not good enough to assure a hit on a factory, to say nothing of a tank.
Abdollahi did not say how the accuracy was measured, but the international standard is circular error probable (CEP).
Throughout, Sion sprinkles in some strange terms and facts: "Circle of error" when he means "circular error probable, a measure of weapon accuracy; Congressional Medal of Honor (it is the Medal of Honor); Messerschmitt 109 (variously called the Me-109, ME-109, Bf-109 in the same paragraph).
After reading Maj Jack Sine's article "Defining the 'Precision Weapon' in Effects-Based Terms" (Spring 2006), I will be interested to see how the concept of circular error probable is applied to anticipated directed-energy weapons.