Proliferated Low Earth Orbit (pLEO) Positioning, Navigation and Timing (PNT)

Navy SBIR 22.4 - Topic N224-131
NAVWAR - Naval Information Warfare Systems Command
Opens: August 11, 2022 - Closes: September 13, 2022 (12:00pm est)

N224-131 TITLE: Proliferated Low Earth Orbit (pLEO) Positioning, Navigation and Timing (PNT)


TECHNOLOGY AREA(S): Electronics; Sensors

OBJECTIVE: Develop navigation concepts using commercial Low Earth Orbit (LEO) satellite constellations as signals of opportunity to provide accurate Global Positioning System (GPS)-independent positioning and precise timing with a positioning accuracy of less than 50 meters 3-D (Spherical) Position (95%), less than 6 meters/second velocity error (RMS per axis), and better than 50 nanosecond time transfer (95%) (threshold).

Objective performance requirements are less than 10 meters, less than 3 meters/second, and better than 20 nanosecond time transfer.

DESCRIPTION: Current naval navigation systems are heavily reliant on GPS, which is a highly accurate all-weather source of positioning, velocity, and timing (PVT). However, GPS utilizes weak radio frequency (RF) signals from distant satellites that may be subjected to intentional and unintentional interference. In recent years, the ability to compromise GPS has been demonstrated by adversaries using jamming techniques that interfere with military mission execution. To mitigate these challenges, the Navy is seeking alternate navigation technologies that can meet and/or rival GPS accuracies for improved PVT when GPS is degraded and/or unavailable. Signals of Opportunity (SoOP) have been considered as an alternative navigation source in the absence of Global Navigation Satellite Systems (GNSS), such as GPS.

As Non-Geosynchronous Orbit (NGSO) satellites become more prevalent, the Navy is exploring Low Earth Orbit (LEO) constellations for low-latency, broadband communications, as well as an APNT source through SoOP. As a goal, the effort should also include fast time to first fix (TTFF) capability of less than 1 minute to achieve the above PVT requirements with presumed course initial positioning in the range of 1 kilometer, and initial time uncertainty in the range of 50 microseconds.

SoOP refers to the use of RF signals out of band or different than the GPS traditional signal waveforms that can be leveraged to perform radio navigation. Such SoOP can be either leveraged in their current state/signal structure/baseband messaging, for example for the purposes of communications, or augmented and/or modified specifically to support precise alternate (to GPS) PVT. While SoOP solutions currently exist (some utilizing LEO satellites, such as using Doppler) these solutions do not provide the positioning accuracies and timing feature that this topic is seeking. This SBIR topic is seeking more creative and innovative SoOP solutions.

The end solution will integrate into PNT suites, such as the GPS-based Positioning Navigation and Timing Service (GPNTS). GPNTS is the Navy’s current and modernized PNT system, replacing the Navigation Sensor System Interface (NAVSSI). It is an open-architecture, data-hosting environment for Navy surface platforms and provides real-time PNT data services, while allowing to the integration of future APNT sources.

This SBIR topic falls under the NDS Alignment of "Modernize Key Capabilities" and the DDR&E (RT&L) Tech Priority "Networked Command, Control, and Communications (C3)."

PHASE I: Propose specific innovative solutions that use LEO satellite constellations as signals of opportunity to derive and provide accurate positioning and timing. Consider exploring modifications to signal structures, including specific navigation messages and improved cognitive waveforms, to maintain sufficient ratio of Energy per Bit to the Spectral Noise Density (Eb/No) to maintain precise range/pseudorange measurements to reach for objective performance requirements.

Describe the technical solution based on the investigation and technical trade-offs performed earlier in this Phase. Identify the means to incorporate the technical solution into the PNT suite, such as the GPNTS.

For the identified solution, develop the SBIR Phase II Project Plan to include a detailed schedule (in Gantt format), spend plan, performance objectives, and transition plan for the identified Program of Records (PoRs).

PHASE II: Develop a set of performance specifications for the hardware and software solution with positioning solution system for GPNTS. Conduct a System Requirements Review (SRR).

Engage with the Program Office in its introduction and collaboration with Naval Information Warfare Center (NIWC) Pacific engineers. Establish a working relationship with PMW/A 170 and NIWC Pacific engineers to perform integration studies to include the identification of any necessary engineering changes to the current GPNTS system. Additionally, establish a working relationship with the engineering team(s) of other potential transition PNT suite target(s).

Develop the prototype solution for GPNTS for demonstration and validation in the GPNTS or equivalent development environment. Conduct a Preliminary Design Review (PDR) and commence development of an Engineering Development Model (EDM) system. Conduct a Critical Design Review (CDR) prior to building the EDM.

Develop the life-cycle support strategies and concepts for the system.

Develop a SBIR Phase III Project Plan to include a detailed schedule (in Gantt format) and spend plan, performance requirements, and revised transition plan for the GPNTS and other potential transition PNT suite target(s).

PHASE III DUAL USE APPLICATIONS: Refine and fully develop the Phase II EDM to produce a Production Representative Article (PRA) of the solution.

Perform Formal Qualification Tests (FQT) (e.g., field testing, operational assessments) of the PRA solution with the GPNTS system and other potential transition PNT suite target(s).

Provide life-cycle support strategies and concepts for the LEO sensor with the GPNTS and other potential transition PNT suite contractor(s) by developing a Life-Cycle Sustainment Plan (LCSP).

Investigate the dual use of the developed technologies for commercial applications, including but not limited to, commercial and privately owned vessels and aircraft. These sensors can provide an additional method of positioning and time that is independent of GPS and available at all times, worldwide.


  1. Raquet, John F. and Miller, Mikel M. "Issues and Approaches for Navigation Using Signals of Opportunity." (2007). RTO-MP-SET-104.
  2. McEllroy Jonathan A. "Navigation Using Signals of Opportunity in the AM Transmission Band." Master’s Thesis. DTIC Accession Number ADA456511, 1 September 2001.
  3. Perdue, Lisa; Fischer, John, and Dries, Ronald. "Signals of Opportunity as an Augmentation or Alternative to GNSS for Critical Timing Applications." Proceedings of the 2017 Precise Time and Time Interval Meeting, ION PTTI 2017, Monterey, California, January 30-February 2, 2017.
  4. Mitola, Joseph III. "Cognitive Radio An Integrated Agent Architecture for Software Defined Radio." Dissertation for Doctor of Technology, Royal Institute of Technology, Sweden, 8 May 2000.
  5. Jones, Michael. "Signals of opportunity: Holy Grail or a waste of time?" GPS World, 22 Feb 2018.
  6. Psiaki, Mark L. "Navigation using carrier Doppler shift from a LEO constellation: TRANSIT on steroids." ION NAVIGATION. 2021, Volume 68, Issue 3, pp. 621–641.,-Mark%20L.&text=Abstract%3A,alternative%20to%20pseudorange%2Dbased%20GNSS.

KEYWORDS: Global Positioning System; GPS; Position Navigation and Timing; PNT; Assured PNT; APNT; GPNTS; Non-Geostationary Orbit; NGSO; Low Earth Orbit; LEO; proliferated LEO;; PLEO; signals of opportunity; SoOP; Velocity; Position Velocity and Timing; PVT


TPOC-1: McLaina Mazzone

Email: [email protected]


TPOC-2: Joseph Schnecker 

Email: [email protected]


The Navy Topic above is an "unofficial" copy from the Navy Topics in the DoD 22.4 SBIR BAA. Please see the official DoD Topic website at for any updates.

The DoD issued its Navy 22.4 SBIR Topics pre-release on July 12, 2022, which opens to receive proposals on August 11, 2022, and closes September 13, 2022 (12:00pm ET).

Direct Contact with Topic Authors: During the pre-release period (July 12, 2022 thru August 10, 2022) proposing firms have an opportunity to directly contact the Technical Point of Contact (TPOC) to ask technical questions about the specific BAA topic. Once DoD begins accepting proposals on August 11, 2022 no further direct contact between proposers and topic authors is allowed unless the Topic Author is responding to a question submitted during the Pre-release period.

SITIS Q&A System: After the pre-release period, proposers may submit written questions through SITIS (SBIR/STTR Interactive Topic Information System) at, login and follow instructions. In SITIS, the questioner and respondent remain anonymous but all questions and answers are posted for general viewing. The SITIS system closes to new questions August 30, 2022 at 12:00pm ET.

Topics Search Engine: Visit the DoD Topic Search Tool at to find topics by keyword across all DoD Components participating in this BAA.

Help: If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk via email at [email protected]

[ Return ]