The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1989
Filed:
Dec. 31, 1986
Rex B Peters, Woodinville, WA (US);
Sundstrand Data Control, Inc., Redmond, WA (US);
Abstract
A system and method for precisely and continuously estimating the path length between the entrance of a borehole and a probe (10) which is supported by an elastic cable (14) and carries a gyrocluster (42) and accelerometer cluster (40). The precise estimate of borehole path length is used to aid the inertial navigation performed within the survey system and is selectively determined by integration of either the rate at which the probe (10) moves along the borehole or a compensated cable feed rate that is based on the rate at which the cable (14) passes into or out of the borehole with correction being made for changes in temperature and gravity induced cable stretch. Selection of the rate to be integrated at any given time being determined by whether the rate at which probe (10) moves along the borehole exceeds the compensated cable feed rate by a predetermined amount.