초록 ▼

A sensor assembly suitable for use in an airborne shooter localization system. The sensor assembly has a pressure sensor subassembly with a pressure transducer positioned to detect pressure variations associated with a shock wave from a passing projectile or the muzzle blast following the shock wave

A sensor assembly suitable for use in an airborne shooter localization system. The sensor assembly has a pressure sensor subassembly with a pressure transducer positioned to detect pressure variations associated with a shock wave from a passing projectile or the muzzle blast following the shock wave. To substantially increase the signal to noise ratio for measurements of the shock wave, the pressure sensor subassembly attenuates pressure fluctuations triggered by turbulent airflow over the surface of the subassembly more than it attenuates the shock wave. This preferential attenuation is provided by separating the pressure transducer from the surface of the sensor assembly by a cavity large enough that the pressure fluctuations are substantially attenuated as they propagate across the cavity. Additionally, features of a housing that holds the pressure sensor subassembly facilitate use on an aircraft. Those features include flexibility that allows the sensor assembly to conform to curved surfaces, a skin that provides resistance to environmental conditions and allows the sensor assembly to be attached with an adhesive, and a body region that provides high vibrational impedance to prevent low frequency mechanical vibrations from being coupled to the pressure transducer.

대표청구항 ▼

What is claimed is: 1. A sensor assembly, comprising: a domed surface member having an opening therein; a porous member mounted in the opening in the surface; a pressure sensor, fixedly coupled to the porous member and separated from the porous member by a distance, wherein the distance is such tha

What is claimed is: 1. A sensor assembly, comprising: a domed surface member having an opening therein; a porous member mounted in the opening in the surface; a pressure sensor, fixedly coupled to the porous member and separated from the porous member by a distance, wherein the distance is such that a pressure fluctuation with a frequency of approximately 1 KHz induced by turbulent airflow across the domed surface at the porous membrane is attenuated by at least a factor of 7 as the pressure fluctuation propagates across the distance. 2. The sensor assembly of claim 1, wherein the porous member comprises pores having an average pore diameter of less than 100 microns. 3. The sensor assembly of claim 1, wherein the porous member has pores having an average pore diameter of less than 30 microns. 4. The sensor assembly of claim 3, wherein the porous member comprises sintered stainless steel. 5. The sensor assembly of claim 1, wherein the distance is between 2 mm and 15 mm. 6. The sensor assembly of claim 1, wherein the distance is between 4 mm and 7 mm. 7. The sensor assembly of claim 6, wherein: the domed surface comprises an outer surface of a flexible support member; the flexible support member further comprises: a second surface; a compressible region disposed adjacent the domed surface and between the domed surface and the second surface. 8. The sensor assembly of claim 7, wherein: the compressible region comprises an open cell foam; the pressure sensor comprises a microphone; the sensor assembly further comprises a rigid support member, the pressure sensor and the microphone being attached to the rigid support, the rigid support member being mechanically coupled to the domed surface member, with the rigid support member separated from the second surface. 9. A sensor assembly, comprising: a flexible support member having an first surface and a second surface, the flexible support member comprising a region between the first surface and the second surface, the flexible support member having an opening therein, the opening extending through first surface; a pressure sensor sub-assembly disposed within the opening, the pressure sensor sub-assembly being spaced from the second surface, and the pressure sensor sub-assembly comprising: a rigid support having a first end and a second end, with a cavity between the first end and the second end; a porous member disposed at the first end, the first end being positioned adjacent the first surface; and a pressure sensor disposed at the second end. 10. The sensor assembly of claim 9, wherein the region of the flexible support comprises open cell foam. 11. The sensor assembly of claim 10, wherein the open cell foam comprises open cell polyurethane foam. 12. The sensor assembly of claim 11, wherein first surface and the second surface comprise vacuum molded polyurethane. 13. The sensor assembly of claim 9, wherein the first surface and the second surface comprise non-porous surfaces. 14. The sensor assembly of claim 13, wherein the support member comprises a port adapted to equalize a pressure within the region relative to a pressure outside the region. 15. The sensor assembly of claim 14, wherein the second surface has a planar extent with a smallest dimension and the first surface is domed, providing a maximum separation between the first surface and the second surface, wherein the smallest dimension is at least eight times the maximum separation. 16. An aircraft comprising an outer skin and a plurality of sensor assemblies, each sensor assembly comprising: a flexible support member having a domed surface member and a second surface, the flexible support member comprising a region between the first surface and the second surface, the flexible support member having an opening therein, the opening extending through first surface; a porous member mounted in the opening in the domed surface; a pressure sensor, fixedly coupled to the porous member and separated from the porous member by a distance, wherein second surface is affixed to the outer skin. 17. The aircraft of claim 16, wherein: the sensor assembly is circular, having a diameter, and the domed surface extends to a peak that is distance above the second surface that is less than one eighth of the diameter; the opening is at the peak of the dome. 18. The aircraft of claim 17 wherein: the sensor assembly further comprises foam between the domed surface and the second surface; the domed surface and second surface comprise vacuum formed polyurethane forming an enclosure, enclosing the foam; and the enclosure has an air inlet. 19. The aircraft of claim 15, wherein: the pressure sensor is separated by a distance over which frequency components of eddies at a frequency are attenuated by a factor of 10 when the eddy propagate across the distance; the aircraft further comprises: an electronics assembly comprising a high pass filter having a cutoff frequency such that a signal at the frequency is attenuated by at least 3 dB in the filter; a signal conductor coupling an output of the pressure sensor to the electronics assembly through the high pass filter. 20. The aircraft of claim 19, wherein the aircraft is a helicopter.