Applied Physical Sciences Corp. | Date: 2011-04-29
Techniques are provided for sparse array RF imaging for surveillance applications. The present invention enables object image identification using a sparsely populated array of distributed radio nodes deployed and operated as a radar detection, tracking and identification application. Three-dimensional object images are formed, from which estimates of extent and shape can be extracted for objects that are detected in the vicinity of the deployed radar array. In addition, techniques are provided for the identification and/or classification of vehicles, humans and fauna through feature extraction from the formed three-dimensional images.
Applied Physical Sciences Corp. | Date: 2015-06-01
Techniques are provided for sparse array RF imaging for surveillance applications. Objects in a three dimensional (3-D) image-data-set obtained from multi-static radio frequency detection data are classified, for example, as human or non-human. One or more geometric image features are extracted from the image-data-set that support a target classification process; and the one or more objects are classified as a threat based on a parametric evaluation of the extracted geometric image features.
Applied Physical Sciences Corp. | Date: 2013-08-08
A coherent sound source is provided for marine seismic surveys. An underwater sound projector for producing time-harmonic waveforms comprises two pistons positioned on either side of an electro-magnetic force generator substantially having mechanical and magnetic symmetry about its geometric center thereby creating a virtual node to substantially cancel reaction loads that occur when the pistons are actuated. The underwater sound projector optionally also includes control systems to improve the fidelity of the force generator, provide pressure compensation to the pistons, finely adjust the static position of the pistons, and change the depth and roll when it is configured as tow body. A plurality of underwater sound projectors can be configured in an array. A load-bearing umbilical can connect the underwater sound projectors to a ship, transmit electrical power to each array element and serve as a duplex data transmission medium to route commands from the ship to the projector and report machinery status to the ship.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.96K | Year: 2013
Applied Physical Sciences and the Navmar Applied Sciences propose to adapt existing vector sensor and sonobuoy technology within their respective areas of expertise to develop a preliminary design for a passive deep water directional sonobuoy. The Phase I Base is centered on tasks pertaining to vector sensor design with emphasis on achieving the stringent noise floor criteria in an A-Size sonobuoy form factor. Other critical tasks include those concerning sonobuoy design which focuses on aspects related to packaging, deployment, hydro-mechanical self-noise, and telemetry. A small task will be conducted to obtain preliminary system level performance predictions of the vector sensor in an operationally significant environment. During the Phase I Option prototype designs for the pressure hydrophone and pressure-gradient hydrophone will be fabricated and tested for model validation purposes. The same type of test and evaluation approach will be employed to assess the fidelity of the hardwire telemetry link which routes the data from the sensor to a surface float.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 149.98K | Year: 2012
Sonar performance predictions are often unreliable due to the lack of accurate information about the acoustic properties of the ocean around the globe. We propose to demonstrate an environmental estimation technique that uses reverberation from active sonar transmissions to infer environmental properties including the sound speed profile, the seafloor geoacoustic properties, and the geographically varying seafloor scattering strengths. By exploiting the linear dependence of the reverberation level on the seafloor scattering strength, an analytic method for estimating the scattering strengths can be used to greatly reduce the computational burden and increase the accuracy of the estimated environmental parameters. The result of this environmental estimation will be a fully three dimensional (3D) estimate of the environment, which can then be used to estimate the probability of detection and probability of false alarm versus range, depth, and azimuth relative to the sonar. The estimated environment will then be used to determine a set of sonar transmission parameters which optimize performance.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.99K | Year: 2013
Applied Physical Sciences (APS) has developed a plan to improve the design and development of submarine towed array vector sensors that employ single crystal accelerometers so that they meet Navy specifications, but do so at significantly lower cost relative to earlier variants. Tasks in the Phase I study include developing a comprehensive cost-model which will ascertain the feasibility of various fabrication approaches for all the components that comprise the entire sensor. As a part of this process, APS has teamed with TRS Technologies to evaluate innovative electroding and bonding techniques to reduce the costs single crystal accelerometers. With that, the proposed effort centers on a series of analytical and numerical evaluations, proof-of-concept experiments, and an assessement of a prototype vector sensor suitable for towed array applications.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 736.87K | Year: 2013
The US Navy, Naval Surface Warfare Center (NSWC) plans to upgrade its facilities at the Acoustic Research Detachment (ARD). Part of this upgrade includes installation of volumetric measurement arrays to characterize the radiated acoustic signatures of scale submarine models. At low and mid-frequencies the planned volumetric arrays will likely resemble those currently installed at the Southeast Alaska Acoustic Measurement Facility (SEAFAC) and the South TOTO Acoustic Measurement Facility (STAFAC). These arrays, however, do not extend into the high-frequency (HF) range above 10 kHz. The purpose of this SBIR is to develop an HF Volumetric Array conforming to the requirements given by NSWC. This array would eventually be integrated into the permanent test infrastructure at ARD.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.98K | Year: 2013
With the continual reduction in radiated acoustic levels of submarines around the world, active sonar has become essential in all aspects of Anti-Submarine Warfare (ASW) operations. Further, bistatic and multistatic active sonar systems increase the spatial diversity of detection systems and afford improvements over monostatic systems in performance against potential threat submarines. Source development has been a focus, but the size and complexity of source designs, particularly at the lower frequencies necessary for longer range acoustic propagation, makes this aspect of the active sonar system technically challenging. This is especially true for air-deployable multistatic active sonar systems. An airborne acoustic source, combined with a field of air-deployed acoustic sensors in the water, has the potential to enable a wide area, active, search capability that limits the ability of submerged threats to effectively predict source location and reduce their own vulnerability to detection. The purpose of this SBIR proposal is to: Assess the feasibility of airborne acoustic sources for active sonar Develop source concepts that provide the ensonification levels and source waveforms necessary for submerged threat detection, and Plan at-sea experiments to validate the concepts for development.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 492.96K | Year: 2012
The Phase II effort consists of a 12-month Base and two 6-month Options. The Base is centered on the design, fabrication, and test of a prototype projector and power electronics. Testing is planned at NUWC Seneca Lake to evaluate the projector"s electro-acoustic performance. The first Option is geared on the design, fabrication, and test a prototype acoustic communication system that relies on the hardware developed during the Base. Testing is planned at NSWC Lake Pend Oreille to evaluate the communication system"s performance resulting from the transmission of PRN, BPSK, and QPSK waveforms. The second Option considers a system engineering study to transition the prototype communication system for use at the Aloha Cabled Observatory located 100 km from Oahu, HI.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 779.10K | Year: 2012
Applied Physical Sciences Corp. (APS) will develop designs and proof-of-concept devices to demonstrate a marine mammal detection capability for a variant of the AN/SSQ-125 active source sonobuoy. Acoustic transducers, signal processing algorithms, and data interfaces will be developed and tested. Surrogate targets will be used to facilitate testing. Open-water testing will also use surrogate targets although animals from the U.S. Navy Marine Mammal program may be utilized if separate funding is identified and appropriate approvals are secured. A detailed integration design for the AN/SSQ-125 will be developed to guide plans for a transition effort to PMA-264