Systems, methods, and apparatuses for taking pressure measurements are provided. A multi-hole pressure sensor probe can include a probe tip having a plurality of probe tip holes. The probe tip holes can lead to probe tip channels that convey fluid from the measurement environment to pressure transducers. The pressure transducers can operate using optical transduction techniques. A light source can be applied to the diaphragm, and the light reflected from the diaphragm changes as the position of the diaphragm changes. Further, a reflective material can be applied on the backside of the diaphragm to increase its reflective properties. The light can then be collected and analyzed using a photodiode to determine the environmental pressure acting on the different holes of the probe.

An aspect of the invention is directed to a system of both atmospheric and underwater sensors for measuring pressure waves from a noise source. A system of pressure sensors can be formed to determine the location of an external noise source, whether in air or underwater. The system includes at least two arrays consisting of pressure sensors, including at least one atmospheric pressure sensor and at least one underwater pressure sensor, such as a hydrophone. Each sensor may be a seven-fiber intensity modulated fiber optic pressure sensor. The system includes an analog to digital converter for digitizing the pressure data received from each sensor and a processor which processes the received signals to calculate an approximate location of the noise source based upon the pressure signals received by the sensors at different times of arrival. The system can provide this capability in remote applications due to its low power requirements.

An aspect of the invention is directed to a system of both atmospheric and underwater sensors for measuring pressure waves from a noise source. A system of pressure sensors can be formed to determine the location of an external noise source, whether in air or underwater. The system includes at least two arrays consisting of pressure sensors, including at least one atmospheric pressure sensor and at least one underwater pressure sensor, such as a hydrophone. Each sensor may be a seven-fiber intensity modulated fiber optic pressure sensor. The system includes an analog to digital converter for digitizing the pressure data received from each sensor and a processor which processes the received signals to calculate an approximate location of the noise source based upon the pressure signals received by the sensors at different times of arrival. The system can provide this capability in remote applications due to its low power requirements.

An apparatus for producing strain in an optical fibre proportional to dynamic pressure fluctuation in the surrounding substance. The apparatus includes a diaphragm having a first face that, in use, is exposed to dynamic pressure fluctuations in the substance, and a second, opposite face, the diaphragm being adapted to flex in response to dynamic pressure fluctuations applied to it. One or more optical fibres are mounted on either the first or the second face of the diaphragm, whereby strain is produced in the fibre when the diaphragm flexes.

An apparatus for producing strain in an optical fibre proportional to dynamic pressure fluctuation in the surrounding substance. The apparatus includes a diaphragm having a first face that, in use, is exposed to dynamic pressure fluctuations in the substance, and a second, opposite face, the diaphragm being adapted to flex in response to dynamic pressure fluctuations applied to it. One or more optical fibres are mounted on either the first or the second face of the diaphragm, whereby strain is produced in the fibre when the diaphragm flexes.

A single complex calculation for locating a dominant frequency, such as an interfering signal in a frequency range, is replaced by several much easier ones. A signal is analyzed over a first frequency range to locate at least one comparatively significant frequency component therein. This can involve analyzing, using electronic hardware, a test range of frequencies to identify a potentially significant component within the test range; and determining, using electronic hardware, if a condition for finishing the analysis has been met. If the condition has not been met, the test range is modified as a result of the analysis and the operations of analyzing and determining are repeated.

A single complex calculation for locating a dominant frequency, such as an interfering signal in a frequency range, is replaced by several much easier ones. A signal is analyzed over a first frequency range to locate at least one comparatively significant frequency component therein. This can involve analyzing, using electronic hardware, a test range of frequencies to identify a potentially significant component within the test range; and determining, using electronic hardware, if a condition for finishing the analysis has been met. If the condition has not been met, the test range is modified as a result of the analysis and the operations of analyzing and determining are repeated.

A method for making a housing that defines a cavity for a pressure sensor, the method comprising: providing a bulk of material that will form the housing; focusing a radiation beam on internal portions of the bulk of material so as to modify the internal portions, thereby defining the housing's shape, wherein upstream of the focus of the radiation beam other portions of the bulk material remain unmodified; and discarding either the modified portions or the unmodified portions of the bulk material so as to form the cavity.

An optical sensor (10) comprises an optical cavity defined by a dielectric body and responsive to one or more physical environmental conditions, and a waveguide (70) having a terminal end spaced apart from the optical cavity such that light is optically coupled from the terminal end of the waveguide (70) to the optical cavity. The waveguide (70) is arranged such that, in use, it is maintained at a first temperature that would not damage the optical coupling to the optical cavity when the dielectric body is maintained at a second temperature sufficient to damage the optical coupling to the optical cavity.

An aspect of the invention is directed to a system of both atmospheric and underwater sensors for measuring pressure waves from a noise source. A system of pressure sensors can be formed to determine the location of an external noise source, whether in air or underwater. The system includes at least two arrays consisting of pressure sensors, including at least one atmospheric pressure sensor and at least one underwater pressure sensor, such as a hydrophone. Each sensor may be a seven-fiber intensity modulated fiber optic pressure sensor. The system includes an analog to digital converter for digitizing the pressure data received from each sensor and a processor which processes the received signals to calculate an approximate location of the noise source based upon the pressure signals received by the sensors at different times of arrival. The system can provide this capability in remote applications due to its low power requirements.