Michael Lambert Mahaffey

US Patent:

8275073, Sep 25, 2012

Filed:

Jun 11, 2009

Appl. No.:

12/456075

Inventors:

Stephen T. Ha - Greenville TX, US
Michael L. Mahaffey - Austin TX, US
Frank A. Boyle - Melissa TX, US

Assignee:

L—3 Communications Integrated Systems, L.P. - Greenville TX

International Classification:

H03D 3/00
H04L 27/10
H04J 9/00
H04L 5/04

US Classification:

375323, 375273, 370204

Abstract:

Methods and systems are disclosed herein for discriminating phase-shift-key (PSK) modulated signals from frequency-shift-key (FSK) modulated signals in received signal streams. First, a bit frequency analysis is applied to a digital signal stream representing the received signal stream. The bit frequency analysis computes bit frequencies for bit segments within the digital signal stream. These bit frequencies are then summed in an array to form a bit frequency histogram. Second, a bit phase analysis is applied to the digital signal stream. The bit phase analysis computes bit phases for bit segments within the digital signal stream. These bit phases are then summed in an array to form a bit phase histogram. Spikes within the bit frequency and bit phase histograms can be used to determine whether the received signal stream includes FSK or PSK signals. An enhanced bit phase analysis can also used, if needed.

US Patent:

20230115712, Apr 13, 2023

Filed:

Oct 7, 2021

Appl. No.:

17/496453

Inventors:

- Melbourne FL, US
Michael Lindsey MAHAFFEY - Austin TX, US
Michael Duane SAPP - Garland TX, US
Brian Joseph HOLDEN - St. Paul TX, US

International Classification:

G01C 21/20
G01C 21/00

Abstract:

Data indicative of a line of sight to a target is obtained from a sensor mounted on an aircraft. Data indicative of an orientation of the aircraft relative to the Earth is obtained from a navigation system associated with the aircraft. An expression is generated that couples a first variable indicative of misalignment of an orientation of the sensor and the orientation of the aircraft and a second variable indicative of the location of the target relative to the Earth. The first variable and second variable are determined using the data indicative of the line of sight from the sensor to the target and the expression coupling the first variable and the second variable. The misalignment of the orientation of the sensor and the orientation of the aircraft is compensated for using the first variable. The location of the target relative to the Earth is determined using the second variable.