Honeywell G.m.b.h.

Patricia K Sturm

Kathryn W Ybarra

Gregory T Stayton

Lewis R Motisher

Douglas L Bishop

David F Weymans

Michael H Curtis

A method of processing a plurality of tracks representative of one or more target aircraft in a vicinity of a surveillance aircraft, where each track is generated in response to target reply signals provided by the target aircraft in response to interrogation signals transmitted by the surveillance aircraft, includes eliminating a portion of the plurality of tracks which are duplicate tracks of the same target aircraft. The remaining tracks are maintained and updated in response to the target reply signals provided by the target aircraft. A threat level for each of the remaining tracks is determined and two or more of the remaining tracks which are possibly representative of a same target aircraft are merged resulting in a composite track. The composite track is output to a display device utilizing information from a particular remaining track of the composite track having the greatest threat level to the surveillance aircraft while continuing to maintain and update all the remaining tracks.

Method of track merging in an aircraft tracking system

A method of processing a plurality of replies of target aircraft provided in response to interrogation signals from the surveillance aircraft during surveillance periods to determine whether an altitude track may be initialized for use in a traffic alert and collision avoidance system includes the step of selecting three replies, one from each of three consecutive surveillance periods. The replies have binary or coded altitude data of high or low confidence. The binary or coded altitude data of non-adjacent and adjacent replies of the selected replies are compared and an altitude difference value for each of the comparisons is generated. Further efforts to initialize a track are discarded if any of the altitude difference values are greater than first predetermined separated altitudes if and only if such compared non-adjacent and adjacent replies have binary or coded altitude data of high confidence. The binary or coded altitude data of the non-adjacent and adjacent replies are further compared whether or not the replies have binary data of low or high confidence to determine whether an altitude track may be initialized. The process applies if the altitude data is Gilham code, binary, or other encoded data with single bit errors.

Method of altitude track initialization in an aircraft tracking system

In an aircraft having an aircraft tracking system (ATS), the aircraft being a monitoring aircraft, the monitoring aircraft interrogates target aircraft in the vicinity of the monitoring aircraft in order to determine potentially dangerous situations. The target aircraft responds to the interrogations with parameter information which includes identification (ID). A method of interrogating the target aircraft comprises the steps of receiving unsolicited signals from the target aircraft in the vicinity of the monitoring aircraft. The received unsolicited signals are received by the monitoring aircraft at a first power level. Based on the first power level of the received unsolicited signals, the monitoring aircraft interrogates the target aircraft with a first interrogation signal. The first interrogation signal is transmitted at a second power level, the second power level being based on the first power level of the received unsolicited signal, thereby minimizing interference in the environment and optimizing receipt of the first interrogation signal by the target aircraft.

Method of improved initial transmission of acquisition and tracking

In an aircraft which has a tracking system, the aircraft interrogates all target aircraft in the vicinity of the aircraft in order to determine potentially dangerous situations. The interrogation has a predetermined interrogation sequence which includes interrogation pulses and suppression pulses. The target aircraft respond to the interrogation with predetermined parameter information, the target aircraft sometimes responding to the suppression pulses of the interrogation resulting in an indication of false tracks to the monitoring aircraft. A method is implemented which reduces the false tracks resulting from replies to the suppression pulses. The method comprises the steps of forming tracks on responses to the interrogations wherein the responses meet a first set of predetermined criteria. The formed tracks are then identified as suppression pulse tracks or non-suppression pulse tracks in accordance with a second set of predetermined criteria. Lastly, tracks labelled as suppression pulse tracks are inhibited from being displayed by the tracking system as a potentially dangerous target aircraft to the monitoring aircraft.

Method of reducing false tracks due to suppression pulse replies in an

In a Traffic Alert and Collision Avoidance System on an aircraft having a plurality of antennas, an optimal bearing value is obtained for each target aircraft by generating a target data block for each response to an interrogation, each target data block including a measured bearing value and an associated priority code. A priority code is assigned based on the antenna receiving the information, and the number of valid bearing measurements used to determine a measured bearing value for the reply. If more than one target data block is obtained in a surveillance period, one target data block is retained based on predetermined criteria. The measured bearing value of all the target data blocks having the same, highest priority code are selected or combined, the result being saved in the target data block. The priority codes are then used to select the proper reply bearing measurement, the bearing track update filtering parameters, and to aid in the reply qualification for bearing track initialization.

Method of bearing determination utilizing a bottom antenna in an

In a Traffic Alert and Collision Avoidance System (TCAS), response to interrogations can result in normal, multipath (image), and mixed multipath (potential image) tracks. The method for reducing the number of false tracks includes the steps of selecting a track to be updated from an existing track list. The selected track has the shortest measured range within the highest priority category track. A reply which has not yet been utilized is selected which has parameters which are within predetermined windows of the selected track parameters. (The predetermined windows are equal to or smaller than the windows for lower priority targets.) The selected track is updated using .alpha..beta..gamma. range squared filter, and the selected reply is marked as used. After all tracks are updated, the unused replies are tested to generate new tracks. Then all the tracks are examined to insure that predetermined track category criteria are met, otherwise the track is recategorized.

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Phoenix, AZ, United States of America

Patricia K Sturm