Abstract: A gas turbine pyrometer filtering method and system uses a pyrometer to measure the high pressure turbine blade temperatures using infrared optical detection techniques. The pyrometer signal can be cluttered by positively biased noise. The turbine speed and the pyrometer electrical signal are alternately sampled by an analog to digital converter, and several revolutions of pyrometer data are stored in the local RAM. A data compression algorithm then selects single samples, at evenly spaced intervals, which results in a given number of revolutions, containing an exact number of data points of aligned data in RAM. This data is passed to a clutter rejection filter which then passes only the lowest value for each of the points in all revolutions of data. Thus, the revolutions of acquired data are reduced into a single revolution of filtered data for the current sampling. This single revolution of filtered data in then enter into a circular queue and the last element is discarded.

Abstract: A process, known as the Hick's Probabilistic Data Association Algorithm, correlates sensor measurement to target tracks under condition in which there are numerous false measurements. It accomplishes this by forming multiple hypotheses and computing a probabilistic score for each. The hypothesis with the high score is then used as a probability vector to update each target's track. The result is accomplished by combining the attributes of Joint Probabilistic Data Association (JPDA) and Nearest Neighbor Standard Filter (NNSF). This combination provides an improved algorithm which yields improved performance ever both prior art methods under high clutter conditions with crossing targets.

Abstract: This disclosure concerns the application of the pulse echo principle to the non-intrusive method of low liquid level sensing to determine the level of a liquid in a container. Generally, the sensor is attached to an outer wall of a liquid container by means of an epoxy adhesive. An ultrasonic pulse is transmitted through from the sensor into the container and is reflected back through the epoxy adhesive and the container wall. The acoustic reflection coefficient for the container wall varies depending on whether the wall is backed by a liquid, the level of which is being determined. Specific integral equations which are provided to manipulate the data and to render the sensor less sensitive to noise, wall thickness and reflections from thin liquid levels.