Ryan International Corporation

Paul A Ryan

Dean E Ryan

William C Brodegard

The location of weather activity from a moving platform such as an aircraft is enhanced using triangulation in time. More particularly, a first measurement of the weather activity is made relative to the aircraft at a first time. A second measurement of the location of the weather activity is made from the aircraft at a second period in time. The first measurement is modified or updated to correct for the change in position of the aircraft between the first and second measurements and then the modified data is compared with the data of the second measurement to enhance the location of the weather activity.

Enhancement of storm location from a single moving platform

Two pairs of signals determinative of bearing to a transmitter are developed from two pairs of directional antennas. The signals, converted to digital form, are compared to each other to develop a result signal. The result signal is used to select a primary pair out of the original two pair of signals. The non-primary pair of signals are compared to each other to develop a binary sign bit. The primary signal pair, the result signal and the sign signal are applied to a table to develop a bearing quantity related to the bearing to the transmitter.

Method and apparatus for direction finding

An antenna arrangement on a host aircraft for generating power signals related to a direction from which a transponder reply signal is received from a threat aircraft. The arrangement includes first and second monopole antenna elements arranged along a first axis of the host aircraft, third and fourth monopole antenna elements arranged along a second axis of the host aircraft, with the second axis being orthogonal to the first axis, a first quadrature combiner coupled to the first and second monopole antenna elements for generating first and second signals from the received reply signal, and a second quadrature combiner coupled to the third and fourth monopole antenna elements for generating third and fourth signals from the received reply signal. The respective power levels of the first, second, third and fourth signals are related to the direction from which the reply signal is received from the threat aircraft.

Antenna arrangement and aircraft collision avoidance system

A proximity warning device for aircraft responds solely to transmissions from transponders. The host aircraft has a host transponder and a signal is generated therein and coupled to the device to indicate transmission of a host reply. Selective suppression is implemented based on presence of an SSR beam which is indicated by the signal. Suppression pulses have a fixed duration but randomly selected intervening durations. Data collection proceeds without regard for suppression or the presence of host replies. The shaping of data collection intervals free of interference from suppression provides for improved efficiency for later data decoding and processing. The signal is used to specially mark collected data generated by a host reply. The ability to discriminate between host and other replies allows completely new performance monitoring functions. In one case, the health of the receiver is deduced from the amplitude of host replies. In another case the effectiveness of suppression is noted by capturing host replies in the presence of a suppression pulse.

Aircraft traffic alert and collision avoidance device

A passive aircraft Traffic alert and Collision Avoidance Device (TCAD) is based on sensing and responding to transponder replies of other aircraft to SSR interrogations. In order to avoid masking other aircraft replies by the host transponder TCAD repeatedly and randomly suppresses the host transponder and simultaneoulsly listens for other aircraft replies. Suppression on each occasion is effective for an equal and predetermined duration which is much longer than a typical replay, in a preferred embodiment the suppression/listen duration is 725 .mu.s. In this embodiment the time between successive suppression/listen occasions is random between 725 .mu.s. and 5.025 ms. with an average value of about 2.9 ms. Digital signal processing is used to detect and discard garbled or overlapping replies. Each valid reply, exhibiting a minimum pulse amplitude, is decoded and correlated with a calibrated range parameter and given a time tag. Successive replies which match to within predetermined criteria in time and calibrated range are merged to track the positional relation between the host and other aircraft. The positional relation between other aircraft and the host are evaluated via a priority table in terms of relative altitude and range to locate that craft which poses the highest threat to the host. Parameters of such a craft are displayed. In the event a craft penetrates a shield of programmable size an audible alert is sounded. TCAD provides for shields for each of a plurality of flight regimes, such as terminal, standard and enroute.

A passive aircraft Traffic alert and Collision Avoidance device (TCAD) is based on sensing and responding to transponder replies of other aircraft to SSR interrogations. In order to avoid masking other aircraft replies by the host transponder TCAD repeatedly and randomly suppresses the host transponder and simultaneously listens for other aircraft replies. Suppression on each occasion is effective for an equal and predetermined duration which is much longer than a typical reply, in a preferred embodiment the suppression/listen duration is 725 .mu.s. In this embodiment the time between successive suppression/listen occasions is random between 725 .mu.s. and 5.025 ms. with an average value of about 2.9 ms. Digital signal processing is used to detect and discard garbled or overlapping replies. Each valid reply, exhibiting a minimum pulse amplitude, is decoded and correlated with a calibrated range parameter and given a time tag. Successive replies which match to within predetermined criteria in time and calibrated range are merged to track the positional relation between the host and other aircraft. The positional relation between other aircraft and the host are evaluated via a priority table in terms of relative altitude and range to locate that craft which poses the highest threat to the host. Parameters of such a craft are displayed. In the event a craft penetrates a shield of programmable size an audible alert is sounded. TCAD provides for shields for each of a plurality of flight regimes, such as terminal, standard and enroute. Selection among shields is via a single pushbutton. TCAD allows the pilot to program each of the different shield sizes. Peripheral functions such as altitude deviation alert, density altitude and barometric pressure correction for altitude reporting are also provided.

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Dublin, OH, United States of America

Paul A Ryan