Sr. Signal Processing Engineer

Title: Sr. Signal Processing Engineer Location: Falmouth, MA / On-site Spear AI is a growing defense contracting company delivering solutions that support national security. As we expand, we are building a culture where innovation meets mission-critical work. We operate with a flat organizational structure that lets every team member make an impact, work directly with leadership, and contribute to projects that matter. Whether you join our Hardware, Software, or Services division, you will work alongside people committed to excellence and to advancing the capabilities that keep the country safe. Spear AI builds sonobuoy sensors that are deployed into the water and collect data at the edge. We also work with the U. S. Navy to collect and process their SONAR data. You will have the opportunity to work on real-world projects that directly affect warfighter capability and mission success. Spear AI is seeking a senior signal processing engineer to develop, implement, and field the detection, estimation, and array processing algorithms at the core of our maritime sensor products. You will join an established cross-functional hardware team of mechanical, electrical, embedded software, and data processing engineers, working directly alongside our PhD acoustician. You will be in the lab and out on the water frequently, and the algorithms you write will run on hardware you helped specify. You do not need to come from acoustics. We are looking for depth in signal processing first. If your DSP experience is in radar, RF and communications, EW, sonar, seismics, biomedical signals, speech, radio astronomy, structural health monitoring, or another domain entirely, and you are genuinely interested in moving into underwater acoustics, we want to talk to you. You will not be learning the domain alone: our staff acoustician works on these problems daily and will be your direct partner in getting up to speed on ocean acoustics and propagation physics. Detection theory, estimation theory, and the judgment to know when an algorithm is fooling you are what we cannot teach quickly. Acoustics experience is a plus, not a filter. RESPONSIBILITIES You will work as part of an already formed team, collaborating closely with our acoustician, embedded software engineers, and the mechanical and electrical engineers who build the sensors your algorithms run on. You should have at least some experience in most of the following areas: Detection and Estimation – Develop, characterize, and defend detection and estimation algorithms operating against weak signals in non-stationary, non-Gaussian noise. Quantify performance honestly, including where the algorithm fails. Array Processing – Design and implement beamforming, spatial filtering, bearing estimation, and coherent processing across multi-element arrays. Understand the consequences of real array geometry, element mismatch, and imperfect element position knowledge. Real-Time and Embedded Implementation – Take algorithms from prototype to deployed code with real constraints on compute, memory, and power. Work with our cross-platform DSP library, used both for real-time processing on ARM A-series processors and for traditional cloud compute. Modeling and Simulation – Build the models and synthetic data you need to develop and stress algorithms before hardware exists, and to explain field results after it does. Sensor and Signal Chain Definition – Contribute to the decisions upstream of your algorithms: sensor selection, array geometry, sample rates, dynamic range, anti-aliasing, timing and synchronization, and platform self-noise. Help define the requirements that flow from processing back into hardware. Field Testing and Data Collection – Plan, support, and participate in bench and at-sea testing of algorithms and prototypes, including going to sea during early testing. Design test patterns that actually produce data you can draw conclusions from. Working With Real Data – Collaborate with our data processing and machine learning engineers on labeling, feature extraction, and the boundary between classical signal processing and learned methods. We use both and are not religious about either. Documentation and Handoff – Produce the analysis, documentation, and performance characterization that lets the rest of the team, and our customers, understand what the processing chain does and what its limits are. Incorporate Feedback – Elicit and incorporate feedback from operators, field technicians, and analysts. Our systems are used by people who are not signal processing engineers, and that has to show in the design. REQUIREMENTS · A PhD in electrical engineering, mechanical engineering, ocean engineering, applied physics, applied mathematics, or a related field, with a signal processing emphasis. Alternatively an MS plus 5+ years of relevant post-degree experience, or a BS plus 10+ years of highly relevant experience with at least five years in an algorithm development role. · Deep, demonstrable command of signal processing fundamentals: detection and estimation theory, spectral estimation, adaptive filtering, time-frequency analysis, and array processing. · Strong implementation ability. You write your own code and it works. Python plus a compiled language; C++ preferred. · Experience taking algorithms from concept through to a working system tested against real, messy, recorded data — not only simulation. · Genuine interest in underwater acoustics, whether or not you have worked in it before. · Comfort operating from incomplete requirements in a fast-moving development environment, and the willingness to make and defend engineering judgment calls. · Suitable written and verbal communication skills for working in a high performing development team, including explaining processing decisions to non-specialists. · Ability to physically participate in at sea deployment, test, and recovery operations including ability to lift, carry, and maneuver on a small boat at sea, communicate verbally, and carry out fine manipulations. · You must be willing to receive a Secret or Top Secret/SCI security clearance. This will be at no expense to you. For resources on what a security background investigation involves and what disqualifies people, reference the CIA requirements. Failure to obtain or maintain a clearance will be grounds for termination. DESIRED · Underwater acoustics, sonar, or ocean acoustic propagation experience. · Experience with hydrophones, hydrophone arrays, or other in-water sensing hardware. · Experience with real-time signal processing on embedded Linux. · Publication record or other evidence of original algorithm work. · Prior experience with small boats and at sea operations is strongly desired. · Prior experience with UxS is desired but not required. · Experience supporting or transitioning algorithms into operational or fielded systems. We hope you'll join our fast growing team!