Long-Range Passive Surveillance in Anti-Access/Area-Denial Environments

Navy SBIR 22.1 - Topic N221-019
NAVAIR - Naval Air Systems Command
Opens: January 12, 2022 - Closes: February 10, 2022 (12:00pm est)

N221-019 TITLE: Long-Range Passive Surveillance in Anti-Access/Area-Denial Environments

OUSD (R&E) MODERNIZATION PRIORITY: General Warfighting Requirements (GWR)


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 Announcement. 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 passive surveillance techniques that utilize the wideband signal processing and direction of arrival measurement capabilities of modern signals intelligence/electronic intelligence (SIGINT/ELINT) systems to act as a passive radar system leveraging opportunistic emitters in the operational area to develop and maintain the tactical surface picture in Anti-Access/Area-Denial (A2/AD) environments.

DESCRIPTION: Operations in high-threat environments drive both our own forces, as well as our adversaries, to effectively go dark by limiting detectable emissions. In such situations, long-range situational awareness provided by radar and SIGINT/ELINT systems is lost. However, in most of these environments, particularly those in littoral regions, many other electromagnetic emissions are present from other sources, including commercial ships, land-based emitters, and even satellites. In principle, an airborne platformís mission radar could use these emissions to maintain situational awareness by processing the reflections of these emissions from surrounding ships. However, this requires that not only the opportunistic emission is in the operating band of the mission radar (typically x-band), but also be suitable for the particular radar function (detection/tracking or imaging). This requirement is highly restrictive. On the other hand, modern SIGINT/ELINT collection systems operate over a very wide-frequency range and have wide-instantaneous bandwidth processing capabilities, making them an excellent passive radar system in A2/AD environments where opportunistic emissions may be the only means to develop and maintain a long-range surface picture. The nature of the available emissions should be considered and their suitability for use in vessel detection, tracking, and inverse synthetic aperture imaging over frequency ranges typical of modern SIGINT/ELINT systems.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by DoD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and NAVAIR in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advanced phases of this contract.

PHASE I: Develop passive radar concepts suitable for opportunistic emission exploitation by conceptual modern airborne SIGINT/ELINT systems. Supporting analyses should include the presence of potential opportunistic emissions in littoral and blue water oceanic regions. Hypothetical coverage maps should be developed for operations in peace time, heightened tensions, and during conflicts. The concepts should consider the relatively modest antenna gain (0-3 dBi)of typical SIGINT/ELINT systems. The feasibility of coherent signal processing approaches of these opportunistic emissions should be considered. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Based on Phase I results, candidate concept(s) will be matured through more detailed high-fidelity analyses with a focus on a particular SIGINT/ELINT system identified by the Navy sponsor. Examine integration concepts. Working with the Navy sponsor, assess software and possible firmware impacts to accommodate the candidate techniques. Identify critical technical challenges and perform necessary analysis and as required experimentation to understand the associated risk. The Phase II deliverable should provide a detailed conceptual approach with supporting analyses of sufficient detail to support follow-on design and integration in the candidate airborne platform system. A prototype system should be developed and demonstrated to assess feasibility of the proposed approach.

Work in Phase II may become classified. Please see note in Description paragraph.

PHASE III DUAL USE APPLICATIONS: Complete development, perform final testing, integrate, and transition the final solution to naval airborne SIGINT/ELINT systems.

The technology can support a variety of passive RF surveillance system for air surveillance, facility monitoring, or coastal navigation.


  1. Pavlikov, V. V., Volosyuk, V. K., & Zhyla, S. S. (2018, July). Ultra-wideband passive radars fundamental theory and applications. In 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) (pp. 1-6). IEEE. https://doi.org/10.1109/MMET.2018.8460251.
  2. Matthes, D. (2005, May). Convergence of ESM sensors and passive covert radar. In IEEE International Radar Conference, 2005. (pp. 430-44). IEEE. https://doi.org/10.1109/RADAR.2005.1435863.
  3. Clark, B., & Gunzinger, M. (2015). Winning the airwaves: Regaining America's dominance in the electromagnetic spectrum. Center for Strategic and Budgetary Assessments. https://csbaonline.org/uploads/documents/CSBA6292-EW_Reprint_WEB.pdf.
  4. Department of Defense. (2006, February 28). DoD 5220.22-M National Industrial Security Program Operating Manual (Incorporating Change 2, May 18, 2016). Department of Defense. https://www.esd.whs.mil/portals/54/documents/dd/issuances/dodm/522022m.pdf.

KEYWORDS: Passive radar; anti access/area denial; A2/AD; signal processing; parasitic radar; wideband


The Navy Topic above is an "unofficial" copy from the overall DoD 22.1 SBIR BAA. Please see the official DoD Topic website at rt.cto.mil/rtl-small-business-resources/sbir-sttr/ for any updates.

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