Abstract: A ground-based antenna assembly (10) is provided that includes an assembly base (14) defining a substantially horizontal plane (18) and configured for attachment to a residential, commercial or governmental structure. The ground-based antenna (10) also includes a plurality of planar receiving panels (22) having a circular and/or elliptical shape. The plurality of planar receiving panels (22) are radially-spaced about the assembly base (14) and tilted with respect to the substantially horizontal plane (18) for a receiving field-of-view. The ground-based antenna assembly (10) further includes a plurality of planar transmitting panels (26) having a circular and/or elliptical shape. The plurality of planar transmitting panels (26) are radially-spaced about the assembly base (14) and tilted with respect to the substantially horizontal plane (18) for a transmitting field-of-view.

Abstract: A ground-based antenna assembly (10) is provided that includes an assembly base (14) defining a substantially horizontal plane (18) and configured for attachment to a residential, commercial or governmental structure. The ground-based antenna (10) also includes a plurality of planar receiving panels (22) having a circular and/or elliptical shape. The plurality of planar receiving panels (22) are radially-spaced about the assembly base (14) and tilted with respect to the substantially horizontal plane (18) for a receiving field-of-view. The ground-based antenna assembly (10) further includes a plurality of planar transmitting panels (26) having a circular and/or elliptical shape. The plurality of planar transmitting panels (26) are radially-spaced about the assembly base (14) and tilted with respect to the substantially horizontal plane (18) for a transmitting field-of-view.

Abstract: An array antenna (10) having a plurality of antenna elements (12) keeps only a subset of elements active during normal antenna operation. When a failure of one of the active elements in the array (10) is detected, one of the previously inactive elements (46) is activated to operate as a replacement for the failed element (50). The number of elements that are active during normal operation is selected to achieve a level of antenna performance required by an underlying antenna application. Thus, a desired level of antenna performance is maintained during the life of the array antenna (10) without the consumption of excess power by spare elements in the antenna. Redistributions of inactive element locations are periodically performed during the life of the array antenna (10) to enhance antenna performance in light of failed element locations.

Abstract: A method and apparatus for measuring a level of a material in a tank includes providing a stepped frequency microwave signal to an antenna of a transmitter and receiving in the antenna a received signal from a surface of the material at the level to be measured. A measuring signal containing ranging and calibrating signals is processed in even and odd sample sets input to contiguous narrowband filters formed digitally in a processor using DFT and other algorithms to form true in-phase and quadrature outputs. These outputs are combined and further processed using an interpolation algorithm to isolate ranging and calibration frequency components and to accurately measure the distances represented by such components. The calibration distance associated with the calibration frequency component is compared to a known delay line length and any determined error is used to correct the ranging distance associated with the ranging frequency component.

Abstract: A convolving element which processes sixteen 4-bit samples but may be expanded to convolve both a larger number of samples and a larger number of bits per sample. The expansion occurs through interconnections of identical convolving elements. A selective inversion element inverts particular ones of the convolved samples under the control of a previously loaded binary code. The selective inversion element additionally minimizes interconnections and therefore input/output terminals of the convolving element, by permitting carries for each sample convolved to be accumulated rather than to propagate to more significant elements.

Abstract: The invention provides a method of and apparatus for recording latent photographic images on film by scanning the film in a raster pattern with a spot produced by focusing onto the film a beam of radiation, for example a laser beam, which is modulated in accordance with the retrieval of pictorial data defining an image to be recorded, the data comprising a plurality of elemental data each defining a required spot intensity at a respective elemental image area and a plurality of corrective data defining geometrical distortions of the image to be recorded. Clock signals are produced in accordance with the traverse of the spot, and the elemental data are retrieved in accordance with the production of the clock pulses the production of the clock signals being modified in accordance with the corrective data so as to determine the retrieval of the elemental data so as to set the spot intensity at the required level for each elemental image area as modified by the corrective data.