# US 2025/0093545 A1 · Systems and methods for radio frequency sensing of seismic events > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0093545 A1 - Document ID: US20250093545A1 - Status: Published application - Kind: A1 - Application number: 18/968,171 - Filed: 2024-12-04 - Published: 2025-03-20 - Earliest claimed: 2022-02-11 - Assignees: Eagle Technology, LLC - Applicants: Eagle Technology, LLC - Inventors: Arthur G. Wilson; Vivek Krishna - Web page: https://patentgrep.com/patent/US20250093545A1 ## CPC - G01V 3/12: operating with electromagnetic waves {(operating with millimetre waves G01V8/005)} - H04B 7/18519: {Operations control, administration or maintenance} - H04W 56/005: {compensating for timing error by adjustment in the receiver} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Systems and methods for detecting or predicting a seismic event. The methods comprise, by a system: receiving at least one communication signal using a carrier recovery component with a fixed location remote from a source of the at least one communication signal; determining at least one of (i) phase deviations of the at least one communication signal over time and (ii) differential propagation delays over two paths which the at least one communication signal traveled; performing operations to detect patterns in at least one of the phase deviations and differential propagation delays that indicate an occurrence of seismic activity with level(s) of confidence; and using the level(s) of confidence to detect or predict the seismic event. ## Claims ### Claim 1 A method for detecting or predicting an event using a direct passive phase change measurement approach, comprising: receiving a communication signal at a system having a carrier recovery component with a fixed location remote from a location of a source of the communication signal; using, by the system, the communication signal to generate a reference signal with a range of frequencies less than the range of frequencies of the communication signal; determining, by the system, phase deviations in the communication signal over time by comparing the communication signal to the reference signal; performing, by the system, operations to detect a pattern in the phase deviations that indicates occurrence of structural physical motion of the source with a level of confidence; and use, by the system, the level of confidence to detect or predict the event. ### Claim 2 (depends on 1) The method according to claim 1, wherein the communication signal comprises a signal transmitted from the source with the location where the structural physical motion occurred. ### Claim 3 (depends on 2) The method according to claim 2, wherein the communication signal is either a signal generated by a satellite or a retransmitted signal originating at a ground station. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: receiving a plurality of communication signals at the system; and selecting the communication signal from the plurality of communication signals based on at least one of signal frequency, signal types and signal content. ### Claim 5 (depends on 1) The method according to claim 1, wherein the pattern is detected using a machine learning algorithm. ### Claim 6 (depends on 1) The method according to claim 1, further comprising performing operations by the system to cause a human or a robotic system to take an action for addressing the event which was detected or predicted. ### Claim 7 A method for detecting or predicting an event using a passive bistatic sensing approach, comprising: receiving a direct communication signal and a reflected communication signal by carrier recovery component; obtaining a reference signal; determining, by a signal processor, differential propagation delays over two paths which a communication signal traveled based on the direct communication signal and the reference signal; performing, by the signal processor, operations to detect a pattern in the differential propagation delays that indicates an occurrence of structural physical motion of the source of the direct communication signal with a level of confidence; and use the level of confidence to detect or predict the event. ### Claim 8 (depends on 7) The method according to claim 7, wherein the direct communication signal comprises a signal transmitted from a source located at the location of mechanical disturbance for downlink signals. ### Claim 9 (depends on 8) The method according to claim 8, wherein the direct communication signal is either a signal generated by a satellite or a retransmitted signal originating at a base station. ### Claim 10 (depends on 7) The method according to claim 7, wherein the pattern is detected using a machine learning algorithm. ### Claim 11 (depends on 7) The method according to claim 7, further comprising performing operations to cause a human or a robotic system to take an action for addressing the event which was detected or predicted. ### Claim 12 (depends on 7) The method according to claim 7, wherein the reflected communication signal comprises at least a portion of the direct communication signal which was retransmitted by a physical structure. ### Claim 13 (depends on 12) The method according to claim 12, wherein the differential propagation delays are modulated by relative physical mechanical motion between the source of the direct communication signal and the physical structure. ### Claim 14 (depends on 7) The method according to claim 7, further comprising using the differential propagation delays to determine an amount, degree and or duration of the event. ### Claim 15 (depends on 1) The method according to claim 1, wherein the phase deviations in the communication signal are due to physical motion of the source of the communication signal. ### Claim 16 (depends on 15) The method according to claim 15, further comprising detecting changes in a distance between an emitter of the source and the fixed location of the carrier recovery component based on the phase deviations in the communication signal. ### Claim 17 (depends on 16) The method according to claim 16, further comprising correlating the detected changes in the distance to mechanical event occurrences affecting a structure. ### Claim 18 (depends on 1) The method according to claim 1, wherein the source of the communication signal comprises a satellite and the method further comprises filtering the communication signal to remove any related events caused by perturbations in the motion of the source prior to generation of the reference signal. ### Claim 19 (depends on 1) The method according to claim 1, wherein the source of the communication signal comprises a ground station and the method further comprises filtering the communication signal to remove any effects of wind or other non-seismic events therefrom, prior to generation of the reference signal.