Location
Cocoa Beach, FL
Start Date
7-3-1966 8:00 AM
Description
It became evident a little over a year ago that errors in our knowledge of the force field acting on a ballistic missile in free flight and errors in our knowledge of target location, the so-called geodetic and geophysical (G & G) errors, constitute two of the principal error sources in the Minuteman R & D test program on the Eastern Test Range. We found that individually-measured subsystem miss contributions, when added together on a given flight, would not fully account for the weapon system impact miss derived from the splash net; in other words, we were always left with a significant impact error which could not be attributed to guidance system, control system, propulsion system, separation dynamics, re-entry vehicle, or instrumentation system errors. It was concluded that this remanent error could only arise from either an inaccurately modelled force field in the targeting equations and/or from errors in our assumed knowledge of the target location.
Although new geodetic survey information for Ascension Island and Improved world gravimetric data became available last year from data gathered in the Transit, Anna, SECOR, and other satellite programs, no comprehensive approach had been developed for using these data systems or other schemes for accurately calibrating the total miss contribution due to G & G errors along the Minuteman R & D test trajectory on a flight from Cape Kennedy to the Ascension impact area, TRW Systems investigated the adequacy of the then existing and upcoming satellite programs (such as GEOS and the Calibration Satellite) and ground-based geodetic programs for determining the total G & G impact effect on the Eastern Test Range. It was concluded that the n..st accurate, quickest, and least expensive way to measure the combined G % G error, for the special case of a Minuteman trajectory to Ascension, was to use the existing radar network tracking the Minuteman vehicle .itself. The Minuteman program, therefore, embarked on its own limited special-purpose G & G measurement program.
Calibration of the Impact Errors Due to G&G Uncertainties in the Minuteman R&D Test Program at the Eastern Test Range
Cocoa Beach, FL
It became evident a little over a year ago that errors in our knowledge of the force field acting on a ballistic missile in free flight and errors in our knowledge of target location, the so-called geodetic and geophysical (G & G) errors, constitute two of the principal error sources in the Minuteman R & D test program on the Eastern Test Range. We found that individually-measured subsystem miss contributions, when added together on a given flight, would not fully account for the weapon system impact miss derived from the splash net; in other words, we were always left with a significant impact error which could not be attributed to guidance system, control system, propulsion system, separation dynamics, re-entry vehicle, or instrumentation system errors. It was concluded that this remanent error could only arise from either an inaccurately modelled force field in the targeting equations and/or from errors in our assumed knowledge of the target location.
Although new geodetic survey information for Ascension Island and Improved world gravimetric data became available last year from data gathered in the Transit, Anna, SECOR, and other satellite programs, no comprehensive approach had been developed for using these data systems or other schemes for accurately calibrating the total miss contribution due to G & G errors along the Minuteman R & D test trajectory on a flight from Cape Kennedy to the Ascension impact area, TRW Systems investigated the adequacy of the then existing and upcoming satellite programs (such as GEOS and the Calibration Satellite) and ground-based geodetic programs for determining the total G & G impact effect on the Eastern Test Range. It was concluded that the n..st accurate, quickest, and least expensive way to measure the combined G % G error, for the special case of a Minuteman trajectory to Ascension, was to use the existing radar network tracking the Minuteman vehicle .itself. The Minuteman program, therefore, embarked on its own limited special-purpose G & G measurement program.
