Method of bearing determination utilizing a bottom antenna in an aircraft tracking system
First Claim
1. In an aircraft having a Traffic Alert and Collision Avoidance System (TCAS), said aircraft including a first and second antenna, wherein said aircraft interrogates all target aircraft in the vicinity of said aircraft such that in a surveillance period a predetermined number of interrogations are made during an interrogation portion of the surveillance period, each interrogation being transmitted between said first antenna and said second antenna in a predetermined sequence, said target aircraft responding to each interrogation received such that the same target aircraft responds at least once during a surveillance period, a method for obtaining an optional bearing value for each target aircraft comprising the steps of:
- a) generating a target data block for each response received, each target data block including a measured bearing value and an associated priority code;
b) storing the generated target data blocks in a response list;
c) upon completion of the interrogation portion of the surveillance period, determining the target data blocks which relate to the same target;
d) if only one target data block is found in the response list from step (c),i) retaining that target data block;
otherwisee) if more than one target data block is found in the response list from step (c),i) retaining one target data block in the response list based on predetermined criteria;
ii) combining the measured bearing value of all the target data blocks from step (c) having the same, highest priority code thereby obtaining the optimal bearing value; and
iii) storing the resultant optimal bearing value of step (e, ii) in the retained target data block, along with the priority code of the measured bearing value used in step (e, ii); and
f) repeating step (c) until all detectable duplicate target data blocks for each reponding target aircraft have been eliminated from the response list, each remaining target data block having the optimal bearing value and having an associated priority code for tracking each target aircraft.
3 Assignments
0 Petitions
Accused Products
Abstract
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.
23 Citations
8 Claims
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1. In an aircraft having a Traffic Alert and Collision Avoidance System (TCAS), said aircraft including a first and second antenna, wherein said aircraft interrogates all target aircraft in the vicinity of said aircraft such that in a surveillance period a predetermined number of interrogations are made during an interrogation portion of the surveillance period, each interrogation being transmitted between said first antenna and said second antenna in a predetermined sequence, said target aircraft responding to each interrogation received such that the same target aircraft responds at least once during a surveillance period, a method for obtaining an optional bearing value for each target aircraft comprising the steps of:
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a) generating a target data block for each response received, each target data block including a measured bearing value and an associated priority code; b) storing the generated target data blocks in a response list; c) upon completion of the interrogation portion of the surveillance period, determining the target data blocks which relate to the same target; d) if only one target data block is found in the response list from step (c), i) retaining that target data block;
otherwisee) if more than one target data block is found in the response list from step (c), i) retaining one target data block in the response list based on predetermined criteria; ii) combining the measured bearing value of all the target data blocks from step (c) having the same, highest priority code thereby obtaining the optimal bearing value; and iii) storing the resultant optimal bearing value of step (e, ii) in the retained target data block, along with the priority code of the measured bearing value used in step (e, ii); and f) repeating step (c) until all detectable duplicate target data blocks for each reponding target aircraft have been eliminated from the response list, each remaining target data block having the optimal bearing value and having an associated priority code for tracking each target aircraft. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification