Showing papers on "Secondary surveillance radar published in 1974"

Computer automated radar terminal system

Abstract: An automated radar terminal system employs primary (noncooperative) and secondary (cooperating transponder) surveillance radar equipment to monitor the ensemble of aircraft disposed within a subject air space. A data acquisition subsystem supplies detected and verified aircraft transponder-emitted beacon messages, and derived parameters which characterize each message such as aircraft range and azimuth, to a data processing subsystem. The central processor and memory structure there included maintain the interrelated target scratch pad, data base and multiple display files for accurately and efficiently presenting flexible combined primary radar video-alpha-numeric displays which typically vary at each of plural controller display stations.

Proximity indication with means for computing the distance from an own station to an interrogating secondary surveillance radar

Abstract: A method and apparatus for determining the distance to a secondary surveillance radar (SSR) station from an own transponder station when another transponder station lies within a monitored region surrounding the own station. The distance information is utilized to modify the operating mode of a proximity indicating system at the own station.

Method and apparatus for measuring passively range and bearing

Abstract: In an aircraft collision avoidance system, a method and apparatus for determining passively the slant range and bearing angle to another transponder equipped aircraft within a selectable proximity to an aircraft (own aircraft) equipped with the collision avoidance system in which the azimuthal lines of position from interrogating standard secondary surveillance radar ground stations to both aircraft and the times of arrival at the own aircraft of the transponder replies of the other aircraft are determined. From such data, the bearing angles to the actual and imaginary locations of the transponder equipped aircraft are calculated and then supplied to a truth table which identifies the bearing angle to the actual location of the transponder equipped aircraft. The slant range to the transponder equipped aircraft is then computed in accordance with a predetermined relationship between the time of arrival of one of the transponder replies and the bearing angle.

Antenna system for primary and secondary radar

Abstract: A common antenna system for a primary and a secondary radar transceiver is described. The primary feeder connected to the primary transceiver is provided with two probes for transmitting and receiving through it the interrogation signals of the secondary transceiver. Two ancillary feeders are mounted on either side of the primary structure to transmit and receive a side lobe suppression signal for the secondary transceiver. The feed system is located at the focus of a reflector common to both primary and secondary transceivers.

Radar system with displaced primary and secondary radiation lobes

Abstract: A radar system having a primary and a secondary radar device each generating respective radiation lobes with the primary radiation device having means for making contact with a target and a secondary radiation device producing a radiation lobe which is displaced from a radiation lobe of the primary device so that the secondary device makes contact with the target following the time delay consumed by the processing of the target echo by the receiver of the primary device.

SAR image quality analysis model

Abstract: : The report describes a SAR (Synthetic Aperture Radar) image quality analysis and an image quality model incorporating the conclusions of the image quality analysis into a SAR system digital simulation. The objective of the model and its development program is to provide a fundamental approach for SAR image quality effects for specific SAR systems (parameter combinations performing specific missions). The model thus provides a relatively economical prediction of the information which can be extracted from a specified radar- mission configuration. The model output is a collection of image quality assessment functions, in particular the TQF (Threshold Quality Factor). Other parameters, which indicate the performance of the SAR system, are available from the digital simulation. These include the point target response (both range and azimuth) along with their locations for a preselected target field configuration.