US 11,656,313 B2
Low-frequency radio navigation system
William J. Dickerson, Cranbrook (CA)
Assigned to Arbiter Systems, Inc., Paso Robles, CA (US)
Filed by Arbiter Systems, Inc., Paso Robles, CA (US)
Filed on Jul. 2, 2021, as Appl. No. 17/367,116.
Application 17/367,116 is a continuation of application No. 16/428,620, filed on May 31, 2019, granted, now 11,085,989.
Prior Publication US 2021/0333349 A1, Oct. 28, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G01S 1/46 (2006.01); G01S 1/68 (2006.01); G01S 7/282 (2006.01); G01S 5/02 (2010.01)
CPC G01S 1/685 (2013.01) [G01S 1/46 (2013.01); G01S 5/0221 (2013.01); G01S 5/0226 (2013.01); G01S 7/282 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A low-frequency radio navigation system comprising:
a transmitter comprising:
a base coded modulator configured to generate a base modulation;
a data coded modulator configured to generate a data modulation; and
wherein the transmitter radiates a low-frequency continuous, constant-power chirped-FM spread spectrum signal, comprising:
the base modulation; and
the data modulation, wherein the data modulation is orthogonal to the base modulation.