A capture effect antenna system in which the course and clearance signals are transmitted from a single antenna array. The clearance carrier signal has a substantial null along the course centerline, to thereby cause significant reduction in the course bends.
A localizer signalling system for guiding a craft along a course defined by double lobe course and clearance radiation patterns of different frequencies has a single array of radiating elements all energized by a "Course" group of frequencies and some or all elements energized by a "Clearance" group of frequencies through directional couplers, the coupling factor of the directional couplers determining the ratio of course frequency power to clearance frequency power energizing the array.
Disclosed is a radiofrequency distributor for a two frequency Instrument Landing System Localizer transmitting antenna array, for the purpose of driving each antenna with predetermined modulated radiofrequency currents of four different types, the distributor consisting of a combination of quarter wavelength power dividers and bidirectional couplers.
A broadband localizer antenna array with an even number of elements is supplied by a backmatched power dividing network comprising two chains of directional couplers and a group of hybrids which divide the power among the elements in accordance with geometrical progessions. The center elements in the array may be spaced 0.6 wavelength apart at the average frequency. Other spacings between the elements are greater than 0.6 wavelength.
A monitoring arrangement for use in a two frequency localizer guidance system using a single antenna array is disclosed. This monitoring arrangement is designed to provide monitoring signals equivalent to those that would be provided by monitors located at a distant point on the course and at a distant point located at a selected angle off the course. Additional monitoring for the clearance transmitter signals and means for determining the existence of major faults such as short circuits or open circuited lines or major injuries to the equipment.
In a survey system involving either differential global positioning (DGPS) or robotic total station (RTS) systems, the mobile station includes the radio system in the surveyor pole and either connects the laser reflector system or the GPS to the top of the pole or provides a connector for releasably connecting the laser reflector system or GPS. Electric connections between the GPS or laser reflector system, and the radio system are made either by using the physical connector between the pole and the GPS or laser reflector system, or by providing separate electrical conductors and electrical connectors from the pole to the GPS or laser reflector. In the case of a RTS system the base station includes a GPS for locating the position of the base station. For added convenience, the pole may be formed in sections and the power supply may include an inductive coupling battery charger. Data communications may also take place using wireless technology such as Bluetooth.
