Alternative Positioning, Navigation and Timing (PNT) Technologies for Global Positioning System (GPS)-Degraded and GPS-Denied Operation
Navy SBIR 2016.1 - Topic N161-002
NAVAIR - Ms. Donna Attick -
Opens: January 11, 2016 - Closes: February 17, 2016

N161-002 TITLE: Alternative Positioning, Navigation and Timing (PNT) Technologies for Global Positioning System (GPS)-Degraded and GPS-Denied Operation

TECHNOLOGY AREA(S): Air Platform, Electronics, Sensors


The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop innovative systems that allow for affordable, robust, alternative forms of radiofrequency (RF) based Positioning, Navigation and Timing (PNT), providing an available substitute in environments where the Global Positioning System (GPS) functionality is degraded or completely denied.

DESCRIPTION: GPS provides extremely precise PNT information and has been extensively deployed in military systems; however, GPS may not be available or reliable in Anti Access, Area Denial (A2/AD) environments. Inertial navigation systems (INS) and precision clocks may extend PNT for short periods, but are subject to growing drift errors when GPS is not available. Alternatives are needed to compliment GPS navigation in GPS denied environments.

Research, develop, integrate and test innovative, affordable, robust, intelligent, and adaptable precise alternative PNT systems that integrate multiple sensors and sources of information, optimally fusing navigation information and seamlessly transitioning between sources and sensors based on the availability of sources and RF interference present.

Candidate technologies for this project include an integrated military GPS/Inertial Navigation System (INS) which preferably combines enhanced-long range navigation (e-LORAN) signals or possibly ground terrain mapping with chip scale atomic clocks (CSAC). LORAN-C was decommissioned in 2010, as GPS was available to provide superior PNT capability on a worldwide basis. Since then, the government has realized that GPS represents a single point of failure which can be denied through unintentional and intentional interference, and that a robust backup to GPS is needed, as outlined in the National Positioning, Navigation, and Timing Resilience and Security Act of 2015 (H.R.1678). E-LORAN has been identified as a strong candidate as a backup PNT source to GPS. The developed technologies should be suitable for use in manned air systems such as the F-35 Joint Strike Fighter, as well as in space, weight and power (SWaP) constrained air vehicles such as small unmanned aerial vehicles (UAVs) and precision guided munitions (PGM).

The system hardware and software architectures should be designed to minimize life cycle costs and to readily adapt to the inclusion or exclusion or different sets of sensors and measurements for use on different platforms having different requirements and constraints. The system should be compatible with military security, environmental and other requirements for aviation navigation systems.

RF based PNT that utilizes a geodetic model (such as World Geodetic System 1984 (WGS-84) coordinates) in addition to the Coordinated Universal Time (UTC), could potentially operate in a relative sense to meet mission requirements, such as precision approach and landing relative to a carrier.

Specific goals include PNT accuracy, availability, and performance comparable to GPS when GPS is denied over critical mission phases and to suitable performance levels for non-critical mission phases. In addition, jam-resistance 60 decibels (dB) greater than GPS without an anti-jam antenna, timing and frequency performance to support mission requirements, operation in all-weather conditions, operation over land and sea environments having minimal distinguishable features with no or minimal supporting infrastructure, robust operation in RF challenged and other types of challenging environments is desired.

PHASE I: Perform analyses and trades to demonstrate concept feasibility and develop navigation and timing system concept solutions for use in different classes of manned, unmanned, and SWAP constrained air vehicles. Combine GPS/INS with one or more robust navigation and timing technologies in configurations and designs which minimize data fusion errors when combining data from multiple navigation and timing sensor systems. Analyze design and performance to support successful mission operations using representative air vehicles, platforms and mission scenarios.

Consider working with platform prime contractors, navigation system prime contractors and others, as appropriate.

Document the analysis results and designs in reports.

PHASE II: Develop the Phase I designs into test beds and prototype systems, and demonstrate and validate performance. Objectives include demos and tests under operational conditions, e.g. flight tests.

Consider working with platform prime contractors, navigation system prime contractors and others, as appropriate.

Document the results and designs in reports.

PHASE III DUAL USE APPLICATIONS: Refine the design, test and integrate operational systems suitable for use in or replacement of deployed navigation systems in new or existing manned and unmanned air vehicles and/or SWaP constrained air vehicles identified by the small business working with the NAVAIR Program Officer. Document results in reports. This technology may also be used for navigation and timing on commercial air and marine vehicle systems, e.g. commercial aircraft. For example, because of the proliferation of low-cost GPS jammers, the FAA is becoming more concerned about the loss of GPS signals due to RF interference, such as recently occurred in the Newark airport area.


1. National Coordination Office for Space-Based Positioning, Navigation, and Timing. (2015). LORAN-C Infrastructure & E-LORAN. Retrieved from

2. eLoran Technologies. (2015). Retrieved from

3. eLoran System Definition and Signal Specification Tutorial, Retrieved from

KEYWORDS: GPS; Global Navigation Satellite Systems; e-LORAN; GPS-denied navigation system; signals of opportunity; Inertial Navigation System

TPOC-1: 760-301-4594

TPOC-2: 760-939-5355

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