Remote detection and measurement of objects
Provided are methods of using electromagnetic waves for detecting metal and/or dielectric objects. Methods include directing microwave and/or mm wave radiation in a predetermined direction using a transmission apparatus, including a transmission element; receiving radiation from an entity resulting from the transmitted radiation using a detection apparatus; and generating one or more detection signals in the frequency domain using the detection apparatus. Methods may include operating a controller, wherein operating the controller includes causing the transmitted radiation to be swept over a predetermined range of frequencies, performing a transform operation on the detection signal(s) to generate one or more transformed signals in the time domain, and determining, from one or more features of the transformed signal, one or more dimensions of a metallic or dielectric object upon which the transmitted radiation is incident. A system and method for remote detection and/or identification of a metallic threat object using late time response (LTR) signals is also disclosed.
1. A system for remote detection of one or more dimensions of an object, the system comprising:
a transmission apparatus, including a directional transmission element, configured to be pointed towards a target, the transmission apparatus being configured to direct a radiation with a first polarization in a predetermined direction, wherein the directed radiation includes at least one of a microwave radiation and a millimeter wave radiation;
a non-imaging detection apparatus configured to detect radiation from an entity resulting from the directed radiation, the detection apparatus being configured to detect radiation that has the first polarization and to detect radiation that has a second polarization that is transverse to the first polarization, the detection apparatus being further configured to generate one or more detection signals in a frequency domain;
a controller, the controller being operable to:
(i) cause the directed radiation to be swept over a predetermined range of frequencies,
(ii) perform a transform operation on the one or more detection signals to generate one or more transformed signals in a time domain, and
(iii) determine, from one or more features of the one or more transformed signals, one or more dimensions of the object upon which the directed radiation is incident, wherein the object includes at least one of a metallic object and a dielectric object; and
a neural network configured to make decision on a presence of the object, wherein the neural network has multiple outputs with a plurality of sub-classifications.
2. The system of claim 1 , wherein the controller is operable to monitor for anti-correlation between detected radiation that has the first polarization and detected radiation that has the second polarization.
3. The system of claim 1 , wherein the detected radiation that has the first polarization is analyzed in the time domain, and the detected radiation that has the second polarization is analyzed in the time domain.
4. The system of claim 1 , wherein the first polarization is detected using a first receiver horn and the second polarization is detected using a second receiver horn.
5. The system of claim 1 , wherein the first and second polarizations are measured using receivers that are oriented parallel to a direction of transmission of the radiation.
6. The system of claim 1 , wherein the first and second polarizations are measured using receivers that are oriented at right angles to a direction of transmission of the radiation.
7. The system of claim 1 , wherein the controller is operable to initiate step (i) upon receiving an activation signal, the activation signal corresponding to a user input and/or detection of the presence of the entity.
8. The system of claim 1 , wherein the controller is configured to normalize according to a range one or more transformed signals.
9. The system of claim 1 , wherein the plurality of sub-classifications correspond to a plurality of object types.
10. The system of claim 9 , wherein the plurality of object types include gun, mobile phone, or keys.
11. A system for remote identification of at least one of a caliber and a barrel length of a metallic threat object, the system comprising:
a transmission apparatus, including a transmission element, configured to direct a radiation in a predetermined direction;
a detection apparatus configured to receive radiation from an entity resulting from the directed radiation and to store an amplitude of the received radiation as a function of frequency;
a neural network configured to make decision on a presence of the metallic threat object, wherein the neural network has multiple outputs with a plurality of sub-classifications; and
a control circuitry, the control circuitry being operable to:
(i) cause the directed radiation to be swept over a predetermined range of frequencies,
(ii) perform a transform operation on one or more detection signals to generate one or more transformed signals in a time domain,
(iii) extract, from one or more features of the one or more transformed signals, an onset of an oscillatory response, and
(iv) identify the barrel length of the metallic threat object from a frequency of the onset of the oscillatory response.
12. A system for remote detection of one or more dimensions of an object, the system comprising:
a transmission apparatus, including a directional transmission element, configured to be pointed towards a target, the transmission apparatus being configured to direct a radiation with a first polarization in a predetermined direction, wherein the directed radiation includes at least one of a microwave radiation and a millimeter wave radiation;
a non-imaging detection apparatus configured to detect radiation from an entity resulting from the directed radiation, the detection apparatus being configured to detect radiation that has the first polarization and to detect radiation that has a second polarization that is transverse to the first polarization, the detection apparatus being further configured to generate one or more detection signals in a frequency domain;
a controller, the controller being operable to:
(i) cause the directed radiation to be swept over a predetermined range of frequencies,
(ii) perform a transform operation on the one or more detection signals to generate one or more transformed signals in a time domain, and
(iii) determine, from one or more features of the one or more transformed signals, one or more dimensions of the object upon which the directed radiation is incident, wherein the object includes at least one of a metallic object and a dielectric object; and
a neural network configured to make decision on a presence of the object based on at least one of:
a first input comprising a sum of correlations between vectors in an array, the vectors in the array comprising a stored signal above a threshold derived by Direct Fourier Transform from the one or more detection signals;
a second input comprising sum of integrated signals above the threshold;
a third input comprising a lowest correlation value between an ideal response for a number of barrel lengths and for a number of weapon calibers stored in memory, and a direct untransformed measured quantity for the one or more detection signals;
a fourth input comprising a sum of correlations between the one or more transformed signals, the one or more transformed signals comprising Complex Fourier Transform of detection signals corresponding to radiation that has the first polarization and detection signals corresponding to radiation that has the second polarization; or
a fifth input comprising a sum of integrated Complex Fourier Transform of the detection signals corresponding to radiation that has the first polarization and the detection signals corresponding to radiation that has the second polarization.