1. An RF disturbance detection system, comprising:
an RF interrogator configured to transmit an RF interrogation signal; and
a plurality of RF transceiver modules configured to respond to the RF interrogation signal by transmitting unique RF response signals, wherein the RF interrogator is further configured to periodically interrogate the RF transceiver modules to detect the power of the corresponding response signals so as to detect any changes in the response signal powers over time.
2. The RF disturbance detection system of claim 1, wherein the RF interrogator comprises an RF reader and wherein the RF transceiver modules comprise RFID tags.
3. The RF disturbance detection system of claim 2, wherein the RFID tags are passive RFID tags.
4. The RF disturbance detection system of claim 2, wherein the RFID tags are active RFID tags.
5. The RF disturbance detection system of claim 1, wherein the transceiver modules are distributed across a ground surface.
6. The RF disturbance detection system of claim 1, wherein the RF interrogator is a wireless access point and the RF transceiver modules are wireless client devices.
7. A method of detecting disturbances, comprising:
distributing a plurality of RF transceiver modules in a monitored area, wherein each RF transceiver module is configured to transmit a unique response signal in response to an interrogation;
interrogating the plurality of RF transceiver modules at a first time;
receiving the unique response signals at a reception point to determine power levels for the received response signals at the first time;
interrogating the plurality of RF transceiver modules at a subsequent second time;
receiving the unique response signals at the reception point to determine power levels for the received response signals at the second time; and
comparing the power levels from the first and second times to detect a presence of an RF disturbance in the monitored area.
8. The method of claim 7, wherein comparing the power levels comprises comparing signal-to-noise ratios (SNRs).
9. The method of claim 7, further comprising continuing to monitor power levels times subsequent to the second time.
10. The method of claim 7, wherein distributing the RF transceiver modules comprises placing the RF transceiver modules on a ground surface.
11. The method of claim 7, wherein the RF disturbance results from a buried object.
12. The method of claim 11, wherein the buried object is an improvised explosive device (IED).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of manufacturing razor blades from a strip material having an upper surface and a lower surface, comprising
(a) offsetting a first lengthwise-extending portion of only one of the surfaces from a second lengthwise-extending portion of the same surface,
(b) flattening the first lengthwise-extending surface portion and the second lengthwise-extending surface portion to remove at least 50% of the offset;
(c) separating the first lengthwise-extending surface portion from the second lengthwise-extending surface portion;
(d) sharpening a lengthwise-extending edge on the separated first lengthwise-extending portion of the strip material at said offset.
2. The method of claim 1, wherein during step (a) the first lengthwise-extending surface portion is offset from the second lengthwise-extending surface portion by at least 10% of the thickness of the strip material.
3. The method of claim 1, wherein during step (a) the first lengthwise-extending surface portion is offset from the second lengthwise-extending surface portion by at least 20% of the thickness of the strip material.
4. The method of claim 1, wherein during step (b) at least 75% of the offset is removed.
5. The method of claim 1, wherein during step (b) at least 90% of the offset is removed.
6. The method of claim 3, wherein during step (b) at least 95% of the offset is removed.
7. The method of claim 1, wherein sharpening a lengthwise-extending edge occurs after step (b) and before step (c), the method further comprising
(e) separating the first lengthwise-extending strip portion into razor blade length sections, each razor blade length section including part of the first lengthwise-extending surface portion and part of the second lengthwise-extending surface portion,
wherein step (c) comprises separating the first lengthwise-extending strip portion from the second lengthwise-extending strip portion on the razor blade length sections to provide the razor blades.
8. The method of claim 7, further comprising attaching the razor blade length sections to a razor housing prior to step (c).
9. The method of claim 7, further comprising attaching the razor blades to blade support members of a razor housing after step (d).
10. The method of claim 1, wherein the first lengthwise-extending surface portion and the second lengthwise-extending surface portion are of approximately equal width.
11. The method of claim 10, wherein a lengthwise-extending edge of the first lengthwise-extending strip portion and a lengthwise-extending edge of the second lengthwise-extending strip portion are sharpened.
12. The method of claim 1, wherein strip material is a metal.