most probable position
Also found in: Acronyms.
most probable position
[′mōst ′präb·ə·bəl pə′zish·ən] (navigation)
The computed position of an aircraft determined by comparing a dead-reckoning position and a loran position determined for the same period of time, in which relative weights are given to the estimated probable errors of each.
That position of a craft judged to be most accurate when an element of doubt exists as to the true position; it may be a fix, estimated position, dead-reckoning position, no-wind position, or some other position as determined from the squares of the estimated probable errors of each.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
most probable position (MPP)


Area of uncertainty around the air plot position is 8 NM/h if TAS is up to 250 knots and 20 NM/h if TAS is greater than 250 knots. Aircraft's most probable position is within this circle.

50% area of probability is 1% along track and 3% across track of distance flown since resetting ground position indicator. Aircraft's most probable position will lie in this area.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved