Abstract: The present invention relates to a method and apparatus for detecting the earth's static electric field and determining the contour of its equipotential lines and surfaces and for utilizing the detected field as a reference for other measurements. In particular, the contour of the field can be determined by sensing the potential at a plurality of points and measuring the differences in potential at the points with a differential static amplifier. Alternatively, a fluxmeter for measuring the electric field vector directly can be used to sense changes in the magnitude and direction of the field. A line defined between two points or a plane defined by three noncolinear points in space can be made to coincide with an equipotential line or surface in space, respectively, by adjusting the relative positions of the points such that either the potential differences between the points or the field components sensed along the defined line or in the defined plane are zero.

Abstract: The present invention relates to a sensing device having a chamber containing positive and negative ions, wherein a fluid flow is directed into the chamber and ionized. The ionized flow passes between a plurality of conductive plates, the outputs from which can be used to indicate physical effects, such as air or gas flow and angular motion.

Abstract: The invention relates generally to measuring the air speed of an object moving within the earth's atmosphere. In particular, the invention provides apparatus which comprises means for causing an air flow to enter an electric E field chamber, proportional to air speed, a portion of the air in the air flow being ionized prior to entry into the E field. Air speed is measured by the current resulting from charge separation in the field.

Abstract: A method and apparatus for utilizing the earth's static electric field as a reference for generating an information-bearing electrical signal. In a particular embodiment, the invention provides a differential static voltmeter having spaced voltage sensing probes and a differential static amplifier which determines the difference in voltage sensed by the probes. Since the probes measure the static voltage which occurs as a vertically oriented gradient in the earth's atmosphere, the voltage difference signal produced by the differential static amplifier is a measure of the disposition of the probes relative to a line usually parallel to the earth's surface, the voltmeter thereby being particularly useful as a pitch and roll stabilization reference and control system for airborne vehicles. In other embodiments, the invention also provides apparatus for defining a horizontal reference plane in the atmosphere and apparatus for sensing the roll or pitch rate of an airborne vehicle.

Abstract: A method and apparatus for utilizing the earth's static electric field to tect and/or avoid orographic protrusions extending from the earth's surface, the invention particularly allows detection of electrostatic field disturbances caused by typical mountain contours at horizontal distances up to five times the height of the mountain contour causing the disturbances. The present method comprises measurement of the horizontal component of the static electric field existing in the earth's atmosphere, the attitude of the platform from which such measurement is taken being essentially held parallel to an "artificial horizon". Orographic protrusions, or terrain obstacles, can thus be detected by an increase in the measured value of the horizontal component of the atmospheric static electric field.