ADS-B radar

• US 9,465,104 B2
• Filed: 01/02/2014
• Issued: 10/11/2016
• Est. Priority Date: 10/05/2013
• Status: Expired due to Fees

• Current Assignee: Jed Margolin
• Original Assignee: Jed Margolin
• Inventors: Margolin, Jed
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US14/146,202
• Publication Number:
  US 20150097714A1
• Time in Patent Office: 1,013 Days
• Field of Search: 342/29, 342/30, 342/118
• US Class Current: 1/1
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft

Abstract

The reliability and safety of Automatic Dependent Surveillance-Broadcast (ADS-B) are improved by using the signals transmitted from an ADS-B unit as a radar transmitter with a receiver used to receive reflections.

Claims

1. A system for sensing aircraft and other objects comprising:

(a) an ADS-B transmitter;

(b) an ADS-B receiver;

(c) an ADS-B antenna;

(d) an ADS-B antenna multiplexer;

(e) an ADS-B processor;

(f) a radar processor;

(g) a datastream comparator;

(h) a display;

whereby

(i) said ADS-B processor is configured to control said ADS-B antenna multiplexer, and said ADS-B multiplexer is configured to allow either said ADS-B transmitter or said ADS-B receiver to use said ADS-B antenna,

(j) said ADS-B processor and said radar processor are configured to work together,

(k) said ADS-B processor is configured to periodically cause said ADS-B transmitter to emit a transmitted signal through said ADS-B antenna multiplexer to said ADS-B antenna,

(l) said transmitted signal is reflected by a target producing a reflected signal,

(m) said reflected signal is received by said ADS-B antenna, and said ADS-B antenna multiplexer is configured to send said reflected signal to said ADS-B receiver,

(n) said radar processor is configured to process said reflected signal from said ADS-B receiver and said transmitted signal from said ADS-B transmitter to determine a range to said target,

(o) said datastream comparator is configured to compare the datastream of said transmitted signal and the datastream from said reflected signal,

(p) said radar processor is configured to display said range on said display,

and whereby

(q) if said range to said target does not match a possible position of said target as reported by ADS-B messages from said target said radar processor is configured to note this on said display as a first attention item,

(r) said radar processor is configured to use the change in the positions of said target as reported by said ADS-B messages received from said target to calculate a reported radial velocity of said target,

(s) said radar processor is configured to use the Doppler shift of said reflected signal to calculate a measured radial velocity of said target,

(t) a discrepancy between said reported radial velocity of said target and said measured radial velocity of said target indicates a system error comprising GPS spoofing, failure of the ADS-B system on said target, or deliberate misreporting by said target and said radar processor is configured to note said discrepancy on said display as a second attention item, and

(u) a receipt of said ADS-B messages from said target that is not confirmed by a reflected signal indicates that a false ADS-B signal is being broadcast and said radar processor is configured to note said false ADS-B signal on said display as a third attention item.

2. A system for sensing aircraft and other objects comprising:

(a) an ADS-B transmitter;

(b) an ADS-B receiver;

(c) a first ADS-B antenna;

(d) a second ADS-B antenna;

(e) an antenna controller;

(f) an ADS-B antenna multiplexer;

(g) an ADS-B processor;

(h) a radar processor;

(i) a datastream comparator;

(j) a display;

whereby

(k) said second ADS-B antenna is directional, and said radar processor is configured to control said antenna controller which is configured to control the direction of said second ADS-B antenna,

(l) said ADS-B processor is configured to control said ADS-B antenna multiplexer, and said ADS-B antenna multiplexer is configured to allow said ADS-B transmitter to use either said first ADS-B antenna or said second ADS-B antenna, and said ADS-B antenna multiplexer is also configured to allow said ADS-B receiver to use either said first ADS-B antenna or said second ADS-B antenna,

(m) said ADS-B processor and said radar processor are configured to work together,

(n) said ADS-B processor is configured to periodically cause said ADS-B transmitter to emit a transmitted signal through either said first ADS-B antenna or said second ADS-B antenna through said ADS-B antenna multiplexer,

(o) said transmitted signal is reflected by a target producing a reflected signal,

(p) said reflected signal is received by either or both said first ADS-B antenna and said second ADS-B antenna, and said ADS-B antenna multiplexer is configured to select either said first ADS-B antenna or said second ADS-B antenna and send said reflected signal to said ADS-B receiver,

(q) said radar processor is configured to process said reflected signal from said ADS-B receiver and said transmitted signal from said ADS-B transmitter to determine a range to said target,

(r) said radar processor is configured to use the direction of said second ADS-B antenna to determine a bearing to said target,

(s) said datastream comparator is configured to compare the datastream of said transmitted signal and the datastream from said reflected signal,

(t) said radar processor is configured to display said range and said bearing on said display,

and whereby

(u) if said range and said bearing to said target do not match the position of said target as reported by ADS-B messages from said target said radar processor is configured to note this on said display as a first attention item,

(v) said radar processor is configured to use the change in the positions of said target as reported by said ADS-B messages received from said target to calculate a reported radial velocity of said target,

(w) said radar processor is configured to use the Doppler shift of said reflected signal to calculate a measured radial velocity of said target,

(x) a discrepancy between said reported radial velocity of said target and said measured radial velocity of said target indicates a system error comprising GPS spoofing, failure of the ADS-B system on said target, or deliberate misreporting by said target, and said radar processor is configured to note said discrepancy on said display as a second attention item, and

(y) a receipt of said ADS-B messages from said target that is not confirmed by a reflected signal indicates that a false ADS-B signal is being broadcast and said radar processor is configured to note said false ADS-B signal on said display as a third attention item.

3. A system for sensing aircraft and other objects comprising:

(a) an ADS-B transmitter;

(b) a first ADS-B receiver;

(c) a first ADS-B antenna;

(d) a second ADS-B receiver;

(e) a second ADS-B antenna;

(f) an antenna controller;

(g) an ADS-B antenna multiplexer;

(h) an ADS-B processor;

(i) a radar processor;

(j) a datastream comparator;

(k) a display;

whereby

(l) said second ADS-B antenna is directional and said radar processor is configured to control said antenna controller which is configured to control the direction of said second ADS-B antenna,

(m) said ADS-B processor is configured to control said ADS-B antenna multiplexer, and said ADS-B antenna multiplexer is configured to allow said ADS-B transmitter to use either said first ADS-B antenna or said second ADS-B antenna, and said ADS-B antenna multiplexer is also configured to allow said first ADS-B receiver to use either said first ADS-B antenna or said second ADS-B antenna, and said ADS-B antenna multiplexer is also configured to allow said second ADS-B receiver to use either said first ADS-B antenna or said second ADS-B antenna,

(n) said ADS-B processor and said radar processor work together,

(o) said ADS-B processor is configured to periodically cause said ADS-B transmitter to emit a transmitted signal through either said first ADS-B antenna or said second ADS-B antenna through said ADS-B antenna multiplexer,

(p) said transmitted signal is reflected by a target producing a reflected signal,

(q) said reflected signal is received by either or both said first ADS-B antenna or said second ADS-B antenna, and said ADS-B multiplexer is configured to select either said first ADS-B antenna or said second ADS-B antenna and send said reflected signal to said second ADS-B receiver,

(r) said radar processor is configured to process said reflected signal from said second ADS-B receiver and said transmitted signal from said ADS-B transmitter to determine a range to said target,

(s) said radar processor is configured to use the direction of said second antenna to determine a bearing to said target,

(t) said datastream comparator is configured to compare the datastream of said transmitted signal and the datastream from said reflected signal,

(u) said radar processor is configured to display said range and said bearing on said display,

and whereby

(v) if said range and said bearing to said target do not match the position of said target as reported by ADS-B messages from said target said radar processor is configured to note this on said display as a first attention item,

(w) said radar processor is configured to use the change in the positions of said target as reported by said ADS-B messages received from said target to calculate a reported radial velocity of said target,

(x) said radar processor is configured to use the Doppler shift of said reflected signal to calculate a measured radial velocity of said target,

(y) a discrepancy between said reported radial velocity of said target and said measured radial velocity of said target indicates a system error comprising GPS spoofing, failure of the ADS-B system on said target, or deliberate misreporting by said target, and said radar processor is configured to note said discrepancy on said display as a second attention item, and

(z) a receipt of said ADS-B messages from said target that is not confirmed by a reflected signal indicates that a false ADS-B signal is being broadcast and said radar processor is configured to note said false ADS-B signal on said display as a third attention item.