Embedded Firmware Engineer (C/C++, Linux)

GDI Infotech, Inc. JOB DESCRIPTION Embedded Firmware Engineer – GNSS / Inertial Navigation Systems Defense / PNT R&D | Client-Confidential Engagement | U.S. Persons Only Client Sector Defense contractor — Position, Navigation & Timing (PNT) technology Engagement Type Contract / Contract-to-Hire (via GDI Infotech) Work Eligibility U.

S. Citizen required — NOFORN program restrictions apply Location Onsite/hybrid with client; specifics confirmed at engagement Period of Performance Initial deliverables due within 180 calendar days of requirements release, plus up to 90 days of post-delivery support ABOUT THE OPPORTUNITY GDI Infotech is supporting a defense technology client that develops mission-specific navigation and timing solutions for government customers.

The client's PNT (Position, Navigation and Timing) Directorate is seeking embedded firmware engineers to support two related Research & Development efforts: a multi-receiver GPS/inertial navigation card (“M-REGI”) and a secure, non-“Over-The-Air” timing and ephemeris delivery system (“Secure Start”). Candidates with strong embedded C/C++ and Linux/RTOS experience, ideally with GNSS or inertial navigation exposure, are strongly encouraged to apply.

WHAT YOU'LL WORK ON

• M-REGI (Navigation Card): Developing embedded C/C++ firmware for a custom circuit card built around a Microchip SAM9X60 ARM processor, integrating dual GPS satellite receivers and a tactical-grade Inertial Measurement Unit (IMU).
• Implementing Multi-Hypothesis Tracking (MHT) logic to arbitrate between two satellite-based navigation solutions using covariance, satellite tracking, and spoofing-detection metadata.
• Secure Start (Timing/Ephemeris POC): Building a proof-of-concept, laptop-based system (Linux/Ubuntu) that generates and delivers precise satellite timing and ephemeris data to a navigation receiver without relying on standard over-the-air signals — reducing vulnerability to spoofing.
• Working from orbital-parameter curve-fit algorithms (SDP4-based), Look-Up Table generation for GPS/Galileo constellations, and Precision Time Protocol (PTP) synchronization.
• Customizing Linux RTOS components (U-Boot, buildroot, kernel) for real-time embedded operation using the Yocto project.
• Building a lightweight CI/CD pipeline appropriate for an R&D environment.
• Documenting code structure, data flow, and user interface/configuration parameters.
• Providing up to 90 days of post-delivery engineering support, including troubleshooting, minor code changes, and knowledge transfer/training. REQUIRED QUALIFICATIONS
• Strong hands-on experience developing embedded firmware in C/C++.
• Experience with embedded Linux, including kernel/buildroot customization and real-time operating system concepts (Yocto project experience a plus).
• Familiarity with serial, USB, and TCP/IP communication interfaces on embedded platforms.
• Ability to work from block diagrams, written specifications, and MATLAB reference scripts to implement equivalent functionality in firmware.
• Comfort working in a small, fast-moving R&D environment with evolving requirements.
• U.S. Citizenship required; ability to comply with NOFORN handling requirements (no dissemination to foreign nationals, entities, or governments). PREFERRED / NICE-TO-HAVE
• Background in GNSS/GPS receiver systems, inertial navigation, or Extended Kalman Filter (EKF) implementations.
• Experience with satellite orbital mechanics or TLE (Two-Line Element) data / SGP4-SDP4 propagation models.
• Familiarity with Precision Time Protocol (PTP) or other precision timing/synchronization systems.
• Experience building CI/CD pipelines for embedded or R&D software workflows.
• Working knowledge of IEEE 730 (Software Quality Assurance Plans) or similar SQA frameworks.
• Prior experience on defense, aerospace, or other ITAR/NOFORN-controlled programs. ABOUT GDI INFOTECH GDI Infotech, Inc. is an IT staffing and recruiting firm specializing in the MSP/MSSP and technology services channel, offering direct hire, contract-to-hire, contract staffing, and onsite project deployment. GDI partners with clients to deliver qualified, vetted technical talent quickly and reliably.