Near-vertical direction finding and geolocation system
First Claim
1. A method for geolocating an RF emitter disposed on or near the ground, the method comprising:
- receiving a signal from the RF emitter at each antenna of an array of N non-collinear antennas, wherein N is an integer greater than 2;
routing the signal received at each of the antennas to one of a bank of N corresponding receivers;
downconverting the N received signals to N downconverted signals;
digitizing the N downconverted signals to digitized signals on N corresponding channels; and
using a processor coupled to a navigation unit;
to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter;
to use a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter;
to transform the Bearing Vector into locally level reference frame; and
to geolocate the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing local terrain data.
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Accused Products
Abstract
A system and method for geolocating an RF emitter disposed on or near the ground includes receiving a signal from the RF emitter at each antenna of an array of N non-collinear antennas, wherein N is an integer greater than 2; routing the signal received at each of the antennas to one of a bank of N corresponding receivers; downconverting the N received signals to N downconverted signals; digitizing the N downconverted signals to digitized signals on N corresponding channels; using a processor to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter; using a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter; transforming the Bearing Vector into locally level reference frame; and geolocating the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing local terrain data.
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Citations
18 Claims
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1. A method for geolocating an RF emitter disposed on or near the ground, the method comprising:
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receiving a signal from the RF emitter at each antenna of an array of N non-collinear antennas, wherein N is an integer greater than 2; routing the signal received at each of the antennas to one of a bank of N corresponding receivers; downconverting the N received signals to N downconverted signals; digitizing the N downconverted signals to digitized signals on N corresponding channels; and using a processor coupled to a navigation unit; to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter; to use a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter; to transform the Bearing Vector into locally level reference frame; and to geolocate the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing local terrain data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for geolocating an RF emitter disposed on or near the ground, the system comprising:
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an array of N non-collinear antennas each configured to receive a signal from the RF emitter, wherein N is an integer greater than 2; a bank of N corresponding receivers each configured to receive a corresponding signal from one of the antennas of the array, the receivers configured to downconvert the N received signals to N downconverted signals and to digitize the N downconverted signals to digitized signals on N corresponding channels; a processor configured; to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter; to use a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter; to transform the Bearing Vector into a locally level reference frame; and to geolocate the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing local terrain data. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification
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- Resources
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Current AssigneeRaytheon Applied Signal Technology Incorporated (Rtx Corporation)
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Original AssigneeRaytheon Applied Signal Technology Incorporated (Rtx Corporation)
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InventorsGooch, Richard P., Roscow, Alan W.
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Primary Examiner(s)Phan, Dao
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Application NumberUS13/046,685Publication NumberTime in Patent Office746 DaysField of Search342/417, 342442-445US Class Current342/417CPC Class CodesG01S 3/023 Monitoring or calibratingG01S 3/043 ReceiversG01S 3/48 the waves arriving at the a...G01S 5/02695 Constraining the position t...G01S 5/12 by co-ordinating position l...
