ABSOLUTE VECTOR GRAVIMETER AND METHODS OF MEASURING AN ABSOLUTE GRAVITY VECTOR

摘要

An absolute vector gravimeter and method of use is provided. The absolute vector gravimeter includes one or more single axis accelerometers, each capable of pointing in at least two directions and calculating an estimated gravity component. Further embodiments provide for estimating a bias in the single axis accelerometer, as well as measuring non-ballistic accelerations along multiple axes and calculating estimated gravity components for each. A resultant non-ballistic acceleration vector can be calculated. Examples for reducing the RMS error in the estimated gravity components are also provided.

主权项

1. An absolute vector gravimeter comprising:
a base; a first single axis gimbal operatively connected to the base, the first single axis gimbal being configured to slew through an angle of at least 2θ degrees, where θ is an angle having a value of greater than 0 degrees; a first single axis accelerometer operatively connected to the first single axis gimbal; and a processor operatively connected to the first single axis gimbal and the first single axis accelerometer, the processor configured to:
i. operate the first single axis gimbal to point the first single axis accelerometer in a first direction, wherein the first direction is at an angle of (90−θ) degrees from an axis of determination, wherein the axis of determination is defined in relation to an instrument-fixed reference frame;ii. operate the first single axis accelerometer to take a first measurement of a first component of a gravity vector, when pointed in the first direction;iii. operate the first single axis gimbal to point the first single axis accelerometer in a second direction, wherein the second direction is oriented at an angle of (90+θ) degrees from the axis of determination;iv. operate the first single axis accelerometer to take a second measurement of a second component of the gravity vector when pointed in the second direction, wherein the first and second measurements are static measurements; andv. use the first measurement and the second measurement to calculate a first estimated gravity component along the axis of determination.