OSW-Reliance 21 SBIR OSW26BZ06-DV025: Compact Passive Radar
Quick Answer
OSW26BZ06-DV025 is an OSW-Reliance 21 SBIR topic under the 2026 SBIR Broad Agency Announcement, Release 6, and it is the only topic in this release that accepts both a Phase I proposal and a Direct to Phase II proposal. Phase I is $314,363 over 12 months. Direct to Phase II is $2,095,748 over 24 months. Both cap the technical volume at 20 pages. The topic opens September 23, 2026 and closes October 21, 2026 through the Defense SBIR/STTR Innovation Portal.
The requirement is a radar that never transmits. In contested anti-access and area-denial environments, active radar emissions act as beacons for adversary electronic warfare, so the Department needs covert sensing using illuminators of opportunity. The topic is explicit: this effort requires a 100 percent receive-only payload, and the sensor shall not transmit any RF energy. That sentence appears again in the Phase II deliverable definition, which requires demonstrating detection and imaging "without emitting any RF energy from the passive sensor itself."
What makes this hard is not passive radar as a concept but the combination of capabilities at a price and size the Department is willing to throw away. Current passive systems are bulky, expensive, and primarily optimized for signals intelligence and electronic support measures rather than radar functionality. They lack the tightly synchronized, multi-channel receivers necessary for direct reference signal acquisition, spatial processing, and clutter cancellation. The Department seeks a paradigm shift toward low-cost, multi-channel attritable sensors designed specifically for high-risk deployments.
Concretely: a small form factor passive X-band radar doing both synthetic aperture imaging and ground moving target indication, light enough for a Group 1 or 2 unmanned aircraft, a loitering munition, or an unattended ground sensor, cheap enough that losing it is acceptable.
Topic At a Glance
Topic number: OSW26BZ06-DV025
Title: Compact Passive Radar
Agency: Office of the Secretary of War, Reliance 21, administered by the OUSW(R&E) SBIR Program
Solicitation: OSW-Reliance 21, 2026 SBIR Broad Agency Announcement, Release 6, Proposal Submission Instructions
Program types accepted: Phase I and Direct to Phase II. This is the only topic in the release offering both
Phase I award: $314,363 over 12 months, technical volume limited to 20 pages
Direct to Phase II award: $2,095,748 over 24 months, technical volume limited to 20 pages, structured as 5 pages of Phase I justification plus 15 pages of Phase II technical proposal
OUSW (R&E) Critical Technology Area: Quantum and Battlefield Information Dominance
Component Technology Priority Area: Integrating Sensing and Cyber
Projected CMMC level requirement: Level 2 (Self)
Export control status: ITAR restricted. The technology within this topic is restricted under the International Traffic in Arms Regulation, 22 CFR Parts 120-130, or the Export Administration Regulation, 15 CFR Parts 730-774
Absolute constraint: a 100 percent receive-only payload. The sensor shall not transmit any RF energy
Band: X-band
Required modes: synthetic aperture radar imaging and ground moving target indication
Host platforms: Group 1 or 2 unmanned aircraft systems, loitering munitions, or unattended ground sensors
Design driver: extreme size, weight, power, and cost constraints, with attritability as an explicit requirement
Technical and Business Assistance: Phase I up to $6,500, Phase II up to $50,000 per project, in addition to the cost ceilings and not subject to profit or fee, using the mandatory SBIR/STTR TABA Request Form in Volume 5
Cost volume: the DSIP online Cost Volume webform is required. No separate Excel template
Topic open date: September 23, 2026
Proposal deadline: October 21, 2026
Submission portal: DSIP at dodsbirsttr.mil
Keywords: passive radar, GMTI, SAR, bistatics
The Two Paths, and How to Choose
This topic appears in both the Phase I table and the Direct to Phase II table of the OSW-Reliance 21 Release 6 topic index. That is unusual and it is the first decision you have to make.
Phase I
$314,363 over 12 months, with a 20-page technical volume. Follow the Phase I Proposal Instructions in the DoW SBIR Program BAA and use the Phase I technical volume template provided as its Appendix A.
The Phase I objective is a feasibility study to determine the scientific, technical, and commercial merit of a small form factor, attritable passive radar architecture. The desired end product is a robust simulation and a basic laboratory prototype that validates the feasibility of detecting targets using signals of opportunity while strictly adhering to the SWaP-C metrics required for expendable systems.
Note that a 20-page Phase I technical volume is generous by SBIR standards, and twice what topic NV024 in this same release allows.
Direct to Phase II
$2,095,748 over 24 months, with a 20-page technical volume divided as follows: Part 1, Phase I Justification, 5 pages maximum, and Part 2, Phase II Technical Proposal, 15 pages maximum.
The statutory basis is 15 U.S.C. 638(cc), which allows the Department to make a Phase II award without regard to whether the concern received a Phase I award for that project.
The feasibility restriction that will disqualify many DP2 proposers
Read this carefully, because it is stricter than what most components impose and stricter than DARPA's equivalent language in the same cycle.
Each eligible topic requires that proposers provide documentation to demonstrate that the feasibility described in the Phase I section of the topic has been met. Feasibility documentation cannot be based upon or logically extend from any prior or ongoing federally funded SBIR or STTR work. Work submitted within the feasibility documentation must have been substantially performed by the proposer or the principal investigator. If technology in the feasibility documentation is subject to intellectual property, the proposer must either own the IP or must have obtained license rights to such technology prior to proposal submission, to enable it and its subcontractors to legally carry out the proposed work.
The Volume 2 instruction repeats it: feasibility documentation must not be solely based on work performed under prior or ongoing federally funded SBIR or STTR work.
Two different formulations appear in the same document, "cannot be based upon or logically extend from" in the DP2 guidelines and "must not be solely based on" in the Volume 2 instruction. The stricter reading is the first, and it is the one to plan against. If your passive radar prototype was built under a prior SBIR or STTR from any federal agency, that work may not be usable as your feasibility basis, and even work that logically extends from it may be excluded.
For a small radar company, much prior work is federally funded, and a great deal of it is SBIR-funded specifically. Before you commit to the DP2 path, audit the provenance of every result you intend to cite. Internally funded development, privately funded development, non-SBIR government contract work, and commercial product development are all cleaner ground.
And the consequence of getting it wrong is severe: if the proposer fails to demonstrate technical merit and feasibility equivalent to the Phase I level as described in the topic, the related Phase II proposal will not be evaluated.
Which path fits you
Choose Direct to Phase II if you have a working multi-channel passive radar receiver with a demonstrated architecture, developed outside prior federal SBIR or STTR funding, and you can substantiate the Phase I feasibility described in the topic in five pages. Choose Phase I if your passive radar capability is at the algorithm and simulation stage, or if your existing hardware traces back to SBIR funding you cannot use as a feasibility basis.
Note that the DP2 award is roughly 6.7 times the Phase I award, which is a large ratio. If you can clear the feasibility bar honestly, the DP2 path is worth the audit effort.
What the Requirement Actually Is
The objective
Develop a low-cost, small form factor, attritable passive radar sensor capable of detecting and tracking targets using external RF signals for tactical unmanned and expendable platforms.
The operational driver
In contested anti-access and area-denial environments, active radar emissions act as beacons for adversary electronic warfare. To ensure survivability, the Department requires covert sensing utilizing illuminators of opportunity.
This effort requires a 100 percent receive-only payload. The sensor shall not transmit any RF energy.
That last requirement is absolute and it is repeated in the Phase II deliverable definition. It has design consequences beyond the obvious. A receive-only system has no control over its illumination geometry, waveform, timing, or power, which means everything conventional radar gets for free must be recovered from the environment. It also means no active calibration, no transmitted reference, and no ability to choose a favorable pulse repetition frequency. And practically, "shall not transmit any RF energy" is worth interpreting conservatively: unintentional emissions from local oscillators, clocks, and digital processing are worth addressing in your design discussion, since an attritable sensor whose digital section radiates is not actually covert.
What is wrong with existing systems
Current passive systems are bulky, expensive, and primarily optimized for signals intelligence and electronic support measures rather than radar functionality. They lack the tightly synchronized, multi-channel receivers necessary for direct reference signal acquisition, spatial processing, and clutter cancellation.
The Department seeks a paradigm shift toward low-cost, multi-channel attritable, meaning expendable, sensors designed specifically for high-risk deployments.
The critique names three specific capabilities that SIGINT-derived hardware lacks: direct reference signal acquisition, spatial processing, and clutter cancellation, all of which depend on tight synchronization across multiple channels. Channel-to-channel phase coherence at low cost is the engineering crux of this topic, and a proposal that treats it casually has missed the point of the paragraph.
The system being sought
This topic seeks the development of a small form factor passive X-band radar featuring both synthetic aperture radar imaging and ground moving target indicator capabilities.
Optimized for extreme size, weight, power, and cost constraints, the payload must be light enough for integration onto Group 1 or 2 unmanned aircraft systems, loitering munitions, or unattended ground sensors.
Three things to notice.
X-band specifically. Passive radar research has historically leaned on VHF and UHF broadcast illuminators, FM radio and digital television, because they are powerful, continuous, and everywhere. X-band illuminators of opportunity are a different and harder problem: the available sources are other radars, satellite downlinks, and communications systems rather than broadcast transmitters. Your proposal has to identify which X-band illuminators you intend to exploit and what their availability and geometry look like in a contested environment. This is arguably the single most important technical judgment in the proposal.
Both SAR and GMTI. These place opposite demands on the collection. Synthetic aperture imaging needs coherent integration over a long aperture with precise platform motion knowledge. Moving target indication needs Doppler discrimination against clutter. Doing both from a bistatic or multistatic passive geometry, on a small platform, is a substantial signal processing burden, and the Phase I language acknowledges it by asking for algorithms that work "under constrained computational limits."
Group 1 or 2 UAS. Group 1 is under 20 pounds gross takeoff weight and Group 2 runs to 55 pounds. That is the payload envelope, and it is severe for a multi-channel coherent receiver plus antennas plus edge processing. Loitering munitions and unattended ground sensors imply the same or tighter.
Phase I Requirements
The objective of Phase I is to conduct a feasibility study to determine the scientific, technical, and commercial merit of a small form factor, attritable passive radar architecture.
Offerors are expected to define a comprehensive system architecture, identifying critical low-cost receiver components, antenna configurations suitable for small form factor platforms, and highly efficient edge-processing hardware.
The effort will include developing proof-of-concept signal processing algorithms for reference signal isolation, clutter cancellation, and target detection and tracking under constrained computational limits.
The desired end product is a robust simulation and a basic laboratory prototype that validates the feasibility of detecting targets using signals of opportunity while strictly adhering to the SWaP-C metrics required for expendable systems.
Reading the Phase I scope
Four architecture elements are named: low-cost receiver components, antenna configurations for small platforms, edge-processing hardware, and three specific algorithms. The three algorithms are reference signal isolation, clutter cancellation, and target detection and tracking, and they correspond directly to the three capabilities the topic says existing SIGINT hardware lacks.
The end product is a robust simulation plus a basic laboratory prototype. Both, not either. And the phrase "strictly adhering to the SWaP-C metrics required for expendable systems" means your Phase I has to commit to numbers: mass, volume, power, and unit cost. A feasibility study that establishes technical performance without bounding cost has not addressed attritability, which is the topic's defining constraint.
Phase II Requirements
Phase II culminates in the delivery of a viable hardware prototype.
Offerors are expected to transition their Phase I concepts into a physical, highly miniaturized sensor prototype suitable for integration onto a small unmanned aircraft system or expendable ground node.
The minimum required deliverable is a functional prototype that successfully demonstrates passive stationary and moving target detection, tracking, and imaging in a realistic outdoor environment utilizing RF illumination, cooperative or non-cooperative signals of opportunity, without emitting any RF energy from the passive sensor itself.
The performer must characterize system performance, demonstrate real-time edge processing that outputs actionable products, and validate that the unit cost and SWaP footprint meet the criteria for a truly attritable tactical asset.
Unpacking the minimum deliverable
Six things are packed into that one sentence, and each is a separate test.
Stationary target detection. Moving target detection. Tracking. Imaging. In a realistic outdoor environment. Without transmitting.
Note "cooperative or non-cooperative signals of opportunity." Cooperative illumination is permitted for the demonstration, which is an important allowance: you may use a known, controlled X-band source rather than depending on whatever happens to be radiating over your test range. That said, the operational value of the system depends on non-cooperative sources, so a demonstration that only works with a cooperative illuminator should be framed honestly as a step, with the non-cooperative case addressed in your risk discussion.
Three additional validation requirements follow. Characterize system performance, which means quantitative detection, resolution, and accuracy figures rather than imagery alone. Demonstrate real-time edge processing that outputs actionable products, meaning the processing happens on the platform and produces something a user can act on, not a raw data dump for later analysis. And validate that the unit cost and SWaP footprint meet the criteria for a truly attritable tactical asset, which is a cost claim you must substantiate, not assert.
That last one deserves emphasis. "Validate that the unit cost meets the criteria for a truly attritable tactical asset" is a bill of materials and manufacturing cost analysis, delivered as part of a technical program. Build the cost model early and update it as the design matures.
Phase III Dual Use
In Phase III, the expendable passive radar sensor is expected to transition into operational military platforms and commercial markets, supported by non-SBIR and non-STTR funding.
For Department applications, the technology will be integrated into launched effects, loitering munitions, and distributed unattended ground sensor networks.
In the commercial sector, potential applications include low-cost air traffic monitoring, counter-unmanned aircraft surveillance for critical infrastructure, and general airspace monitoring where adding active RF spectrum clutter is undesirable or prohibited.
The commercial case here is stronger than it first appears, and the reason is spectrum. A receive-only sensor needs no transmit authorization, which removes the regulatory obstacle that limits deployment of active radar for counter-drone and airspace monitoring at airports, stadiums, prisons, substations, and data centers. The topic names that advantage directly: environments "where adding active RF spectrum clutter is undesirable or prohibited." For a commercialization strategy, that is a concrete, defensible market entry argument rather than a generic dual-use paragraph.
Launched effects is worth noting on the military side. It is a current Army program area with active procurement, and a passive sensing payload for launched effects has an identifiable transition path.
Funding, Cost Structure, and OSW-Reliance 21 Mechanics
The awards
Phase I: $314,363 over 12 months. The Phase I base amount must not exceed the base limit set by the topic.
Direct to Phase II: $2,095,748 over 24 months.
Both figures are oddly precise, which usually indicates a specific funding line rather than a round programmatic allocation. Treat them as ceilings, not targets, and build a budget that fits.
Cost volume mechanics
OSW-Reliance 21 requires the use of the DSIP online Cost Volume webform. No separate Excel template is required. If supplementary cost detail is desired, it may be uploaded as a PDF attachment within Volume 3.
For Direct to Phase II, a detailed cost volume must be submitted online in the proper format shown in the Cost Breakdown Guidance in the DoW 2026 SBIR BAA. Provide enough information to allow evaluators to assess your plans to use the requested funds.
Percentage of Work, with no exceptions
Review the updated Percentage of Work calculation details included in the DoW solicitation. OSW-Reliance 21 will not accept any deviation to the POW requirements.
This matters on a radar topic, where the temptation is to subcontract RF front-end design, antenna design, or embedded processing. Model the POW before you assemble the team.
Technical and Business Assistance
Phase I awardees may request up to $6,500 in TABA funding. Phase II awardees may request up to $50,000 per Phase II project. TABA funding is in addition to the Phase I and Phase II cost ceilings and is not subject to profit or fee.
All requests for TABA must be completed using the SBIR/STTR TABA Request Form, and the completed form must be included in Volume 5 of the proposal submission in DSIP. OSW will not accept requests for TABA that do not utilize the form or that are not included as a submission document in Volume 5.
The $50,000 Phase II figure is at the high end across components in this cycle, and for this topic the highest-value uses are export control counsel, given the ITAR restriction, and manufacturing cost engineering, since validating attritable unit cost is a contract deliverable.
Page limits and the no-appendix rule
For Phase I, the technical volume must follow the DoW SBIR solicitation formatting requirements except that all figures, tables, charts, and references must be included within the page count limit listed in the topic index. Any pages past the technical volume limit will not be considered, and no separate appendices will be evaluated.
For Direct to Phase II, the technical volume is 20 pages maximum: Part 1 Phase I Justification at 5 pages maximum, and Part 2 Phase II Technical Proposal at 15 pages maximum. Within that 15 pages, the Technology Transition and Commercialization Strategy is not to exceed 2 pages and counts toward the 15-page limit.
So a DP2 proposer has 5 pages to establish feasibility, 13 pages of technical proposal, and 2 pages of commercialization strategy. That is tight for a system with two radar modes, a multi-channel receiver, an antenna, edge processing, and a cost model. Plan the page budget before drafting.
What the DP2 technical proposal must contain
The Phase II Technical Objectives and Approach section must list specific technical objectives and provide a detailed technical approach, and it must include the following named subsections.
Phase II Work Plan, with an explicit, detailed description of the approach, indicating what is planned, how and where the work will be carried out, a schedule of major events, and the final product to be developed.
Related Work, describing significant activities directly related to the effort including those of the Principal Investigator, the firm, consultants, or others, and demonstrating the proposers' awareness of the state of the art.
Relationship with Future Research or Research and Development, stating anticipated results and discussing the significance of the Phase II effort as a foundation for Phase III.
Technology Transition and Commercialization Strategy, not to exceed 2 pages and counting toward the 15-page limit, addressing five specific questions: what is the first product this technology will go into; who will be your customers and what is your estimate of the market size; how much funding will you need to bring the technology to market and how will you raise it; does your company contain marketing expertise and if not how will you bring it in; and who are your competitors and what is your price or quality advantage.
Key Personnel, including the Principal Investigator, with directly related education, experience, and relevant publications, and a concise resume of the PI.
Facilities and Equipment, describing available instrumentation and physical facilities, justifying equipment to be purchased including Government Furnished Equipment, and stating whether the facilities meet federal, state, and local environmental laws and regulations across the named groupings. All requirements for government furnished equipment or other assets, and associated costs, must be determined and agreed to during Phase II contract negotiations.
Consultants, describing in detail any involvement of universities, academic institutions, or other consultants and identifying them in the Cost Volume.
Those five commercialization questions are literal and a reviewer will look for all five. Answer them as five answers, not as a narrative that touches on them.
The Company Commercialization Report, and a contradiction
Completion of the CCR as Volume 4 is required.
The Phase I Proposal Guidelines state that information contained in the CCR will be considered by OSW-Reliance 21 during proposal evaluations. The Direct to Phase II Proposal Guidelines in the same document state that the information contained in the CCR will not be considered by "SCO" during proposal evaluations.
The two statements conflict, and the reference to SCO appears to be residual text from another organization's instructions. The safe approach for either path is to complete the CCR carefully and completely, since at least one section of the governing document says it is scored. If the answer materially affects your proposal, raise it through DSIP Topic Q&A before it closes.
Note also that the commercialization strategy in Volume 2 is separate from the CCR. The strategy addresses how you propose to commercialize this research; the CCR covers what you have done to commercialize the results of past Phase II awards.
Supporting documents that are optional but encouraged
Letters of Support from prospective transition stakeholders within DEVCOM C5ISR Center, PAE Maneuver Ground, PAE Maneuver Air, CPE Autonomy, the Naval Research Laboratory, or the Air Force Research Laboratory.
A Data Management Plan addressing provenance, licensing, and protection of pre-training data and government-furnished data.
For this topic the named list is unusually well matched. DEVCOM C5ISR Center is the Army's sensors and electronic warfare organization and is the natural home for a passive radar payload. PAE Maneuver Air and CPE Autonomy connect to the unmanned platform side. A letter from C5ISR is the highest-value optional document here.
If your signal processing uses machine learning trained on RF data, the Data Management Plan is directly relevant rather than boilerplate, and addressing provenance and licensing of your training data is worth doing.
Evaluation and selection
All proposals will be evaluated in accordance with the evaluation criteria listed in the DoW solicitation.
Government technical evaluators from Army DEVCOM C5ISR Center, Army DEVCOM Army Research Lab, the Naval Research Laboratory, and the Air Force Research Laboratory may participate in the evaluation. Non-government support contractors may assist in administrative handling of proposals if the individual has signed a non-disclosure agreement, and they will not participate in selection decisions.
Proposing firms will be notified of selection or non-selection status within 90 days of the closing date of the topic, which is approximately January 19, 2027. Notifications will be issued through DSIP to both the Corporate Official and the Principal Investigator listed on the proposal.
Protests after award should be submitted, as prescribed in FAR 33.106(b) and FAR 52.233-3, to osd.ncr.ousd-r-e.mbx.SBIR-STTR-Protest@mail.mil. Refer to the DoW solicitation for procedures to protest the announcement itself.
Tri-service coordination and the TPOC question
This topic is of joint interest to the U.S. Army, meaning DEVCOM C5ISR Center and DEVCOM ARL, the U.S. Navy, meaning the Naval Research Laboratory, and the U.S. Air Force and Space Force, meaning the Air Force Research Laboratory. Proposers are strongly encouraged to engage the Technical Point of Contact listed in the topic description during the pre-release period to discuss technical scope and transition opportunities across the Services.
No Technical Point of Contact appears in the DV025 topic description, or in any of the four topic descriptions in this release. Use DSIP Topic Q&A, and send administrative questions to osd.pentagon.ousd-atl.mbx.communities-of-interest@mail.mil.
Note that Phase II efforts under this release shall include a transition plan addressing at least two of the three Services. On this topic that is a natural fit, since passive radar payloads have Army, Navy, and Air Force applications, but it is a stated requirement rather than a suggestion.
Classification
Phase I efforts are expected to be performed at the Unclassified and CUI level. Classified proposals are not accepted, and including classified data in an unclassified proposal may be grounds for the Agency to determine the proposal non-responsive and not evaluate it.
In some instances, work being performed on Phase II contracts will require security clearances. If a Phase II contract requires classified work, the offeror must have a facility clearance and appropriate personnel clearances.
For a passive radar topic touching electronic warfare survivability and specific illuminators of opportunity, this possibility is real. Be careful about what you write in an unclassified proposal regarding adversary systems and specific X-band sources, and understand that a facility clearance may become necessary.
Export control and foreign nationals
The technology within this topic is restricted under ITAR, 22 CFR Parts 120-130, or EAR, 15 CFR Parts 730-774.
Offerors must disclose any proposed use of foreign nationals, their countries of origin, the type of visa or work permit possessed, and the statement of work tasks intended for accomplishment by the foreign nationals, in accordance with the Announcement. Foreign national participation will be evaluated on a case-by-case basis and may be restricted due to U.S. export control laws.
Radar signal processing talent is internationally distributed and small radar firms often employ foreign nationals on visas. Resolve this before submitting, with named individuals, countries, visa types, and specific task assignments. Note that the case-by-case language is more accommodating than a flat bar, but the disclosure has to be specific to be evaluated.
The References
Only two, and both are textbooks rather than papers.
Melvin and Scheer, editors, "Principles of Modern Radar: Radar Applications," Volume 3, SciTech Publishing and IET, 2014.
Moo and Ding, "Adaptive Radar Resource Management," Academic Press and Elsevier, 2015.
The brevity is itself informative. Unlike the DARPA topics in this cycle, which cite recent primary literature to point at a specific technical approach, this topic cites the standard reference works. The Government is not steering you toward a particular passive radar technique. It is stating a system requirement and leaving the architecture open.
That has a practical consequence: you will not gain credit for aligning with a cited approach, and you carry the full burden of justifying your architecture from first principles. It also means the "Related Work" section of a DP2 proposal, where you must demonstrate awareness of the state of the art, is doing more work than usual, since the topic gives you no scaffolding. Cite the real passive radar and bistatic literature yourself.
The Moo and Ding reference on adaptive radar resource management is a slightly curious inclusion for a receive-only system, since resource management usually concerns allocating transmit resources. The plausible reading is that it points at managing limited receive and computational resources under constraint, which is consistent with the Phase I emphasis on algorithms that work under constrained computational limits.
Timeline and What to Do When
The dates
Topic opens: September 23, 2026
DSIP Topic Q&A closes: October 7, 2026, two weeks before the topic closes, per the DoW SBIR Program BAA
Proposal deadline: October 21, 2026
Selection notification: within 90 days of the closing date, approximately January 19, 2027
Phase I period: 12 months from award
Direct to Phase II period: 24 months from award
A working backward plan
Before September 23. Decide Phase I or Direct to Phase II. If DP2, audit the funding provenance of every result you intend to cite as feasibility evidence, because work based upon or logically extending from prior or ongoing federally funded SBIR or STTR work is excluded, and failing the feasibility bar means the proposal is not evaluated at all. Confirm the work was substantially performed by your firm or your PI, and resolve IP ownership or licensing. Identify which X-band illuminators of opportunity you intend to exploit and be ready to defend their availability and geometry. Build a preliminary bill of materials and unit cost model, since attritability is the defining requirement. Model your Percentage of Work before finalizing subcontracts. Reach out to DEVCOM C5ISR Center and the other named organizations about a letter of support. Resolve foreign national participation questions with named individuals, countries, visas, and tasks. Confirm SAM registration and CMMC Level 2 self-assessment in SPRS. Download the DoW SBIR Program BAA and its Appendix A Phase I template if bidding Phase I.
September 23 through October 5. Draft the technical volume. For Phase I, 20 pages against the DoW Appendix A template covering the system architecture, low-cost receiver components, antenna configurations, edge processing hardware, the three named algorithms, the simulation plan, the laboratory prototype plan, and the SWaP-C metrics. For DP2, 5 pages of feasibility justification, 13 pages of technical proposal covering the work plan, related work, and future research relationship, and 2 pages of commercialization strategy answering all five named questions. Address the multi-channel synchronization problem explicitly, since it is the capability the topic says existing systems lack. Draft the 3,000 character cover sheet abstract and the 3,000 character anticipated benefits and commercial applications discussion.
October 6 through October 7. Submit remaining questions through DSIP Topic Q&A before it closes, including the CCR evaluation discrepancy if it affects you.
October 8 through October 14. Build the cost volume in the DSIP online webform, following the Cost Breakdown Guidance in the DoW 2026 SBIR BAA. Price receiver hardware, antenna fabrication, edge processing hardware, anechoic or outdoor test range access, and for DP2 the realistic outdoor demonstration campaign. Identify any Government Furnished Equipment requirements, remembering those must be determined and agreed during contract negotiations. Add supplementary cost detail as a Volume 3 PDF if useful. Complete the SBIR/STTR TABA Request Form and place it in Volume 5.
October 15 through October 18. Complete Volume 4, the Company Commercialization Report, carefully. Assemble Volume 5 with the TABA form, letters of support, and a Data Management Plan if your processing uses trained models. Complete Volume 6 training and the Volume 7 foreign affiliations webform, remembering that Volume 7 must be the webform and will not be accepted as a PDF in Volume 5, and that no previous versions should be uploaded to Volume 5. Run compliance: page limits with figures, tables, charts, and references counted inside, no appendices, unclassified or CUI only, no classified data.
October 19 through October 20. Submit and certify in DSIP.
Frequently Asked Questions
What is OSW-Reliance 21 SBIR topic OSW26BZ06-DV025?
OSW26BZ06-DV025 is an OSW-Reliance 21 SBIR topic titled "Compact Passive Radar," released under the 2026 SBIR Broad Agency Announcement, Release 6. The objective is to develop a low-cost, small form factor, attritable passive radar sensor capable of detecting and tracking targets using external RF signals for tactical unmanned and expendable platforms.
Can I submit either a Phase I or a Direct to Phase II proposal?
Yes. DV025 is the only topic in this release that appears in both the Phase I table and the Direct to Phase II table of the topic index. Phase I is $314,363 over 12 months. Direct to Phase II is $2,095,748 over 24 months. Both have a 20-page technical volume limit.
How much funding is available?
Phase I is $314,363 over 12 months. Direct to Phase II is $2,095,748 over 24 months. Phase I awardees may request up to $6,500 in TABA and Phase II awardees up to $50,000 per project, both in addition to the cost ceilings and not subject to profit or fee, using the mandatory SBIR/STTR TABA Request Form in Volume 5.
When is the proposal deadline?
The topic opens September 23, 2026 and proposals are due October 21, 2026 through the Defense SBIR/STTR Innovation Portal at dodsbirsttr.mil.
Can my feasibility evidence come from a prior SBIR award?
No, and this is the most consequential restriction on the DP2 path. Feasibility documentation cannot be based upon or logically extend from any prior or ongoing federally funded SBIR or STTR work. Work submitted must have been substantially performed by the proposer or the Principal Investigator. If the technology is subject to intellectual property, you must own the IP or have obtained license rights prior to proposal submission. Note that the Volume 2 instruction phrases this as "must not be solely based on" prior SBIR or STTR work, which is a weaker formulation than the DP2 guidelines language; plan against the stricter reading.
What happens if my feasibility documentation is inadequate?
If the proposer fails to demonstrate technical merit and feasibility equivalent to the Phase I level as described in the topic, the related Phase II proposal will not be evaluated.
How is the Direct to Phase II technical volume structured?
Twenty pages maximum, divided into Part 1 Phase I Justification at 5 pages maximum and Part 2 Phase II Technical Proposal at 15 pages maximum. Within the 15 pages, the Technology Transition and Commercialization Strategy is not to exceed 2 pages and counts toward that limit.
Can the sensor transmit at all?
No. The topic states that this effort requires a 100 percent receive-only payload and that the sensor shall not transmit any RF energy. The Phase II deliverable definition repeats the constraint, requiring demonstration without emitting any RF energy from the passive sensor itself.
What band is required?
X-band. This is a meaningful constraint, since much passive radar work relies on VHF and UHF broadcast illuminators. X-band illuminators of opportunity are other radars, satellite downlinks, and communications systems rather than broadcast transmitters, so identifying and justifying your illuminator set is a central part of the proposal.
What radar modes are required?
Both synthetic aperture radar imaging and ground moving target indication. These place different demands on the collection and processing, and the Phase I language asks for algorithms that work under constrained computational limits.
What platforms must the payload fit?
Group 1 or 2 unmanned aircraft systems, loitering munitions, or unattended ground sensors. Group 1 is under 20 pounds gross takeoff weight and Group 2 runs to 55 pounds, which sets a severe envelope for a multi-channel coherent receiver plus antennas plus edge processing.
What is wrong with existing passive radar systems?
They are bulky, expensive, and primarily optimized for SIGINT and electronic support measures rather than radar functionality. Specifically, they lack the tightly synchronized, multi-channel receivers necessary for direct reference signal acquisition, spatial processing, and clutter cancellation. Low-cost channel-to-channel phase coherence is the engineering crux of the topic.
What does Phase I have to deliver?
A comprehensive system architecture identifying critical low-cost receiver components, antenna configurations suitable for small form factor platforms, and highly efficient edge-processing hardware. Proof-of-concept signal processing algorithms for reference signal isolation, clutter cancellation, and target detection and tracking under constrained computational limits. And an end product consisting of a robust simulation plus a basic laboratory prototype that validates feasibility while strictly adhering to the SWaP-C metrics required for expendable systems.
What does Phase II have to deliver?
A functional, highly miniaturized hardware prototype demonstrating passive stationary and moving target detection, tracking, and imaging in a realistic outdoor environment using cooperative or non-cooperative signals of opportunity, without emitting any RF energy. The performer must also characterize system performance, demonstrate real-time edge processing that outputs actionable products, and validate that the unit cost and SWaP footprint meet the criteria for a truly attritable tactical asset.
Can I use a cooperative illuminator for the demonstration?
Yes. The Phase II deliverable permits cooperative or non-cooperative signals of opportunity. Since operational value depends on non-cooperative sources, a demonstration relying on cooperative illumination should be framed as a step, with the non-cooperative case addressed in your risk discussion.
Do I have to prove the cost?
Yes. Validating that the unit cost and SWaP footprint meet the criteria for a truly attritable tactical asset is a stated Phase II requirement. That is a bill of materials and manufacturing cost analysis delivered as part of a technical program, so build the cost model early.
Is this topic ITAR restricted?
Yes. The technology is restricted under ITAR, 22 CFR Parts 120-130, or EAR, 15 CFR Parts 730-774. Offerors must disclose any proposed use of foreign nationals, their countries of origin, visa or work permit type, and the specific statement of work tasks assigned to each. Foreign national participation is evaluated case by case and may be restricted.
What CMMC level applies?
The projected requirement for this topic is CMMC Level 2 with self-assessment.
What cost volume format do I use?
The DSIP online Cost Volume webform. OSW-Reliance 21 does not require a separate Excel template. Supplementary cost detail may be uploaded as a PDF attachment within Volume 3. For Direct to Phase II, follow the Cost Breakdown Guidance in the DoW 2026 SBIR BAA.
Are there Percentage of Work restrictions?
Yes. OSW-Reliance 21 will not accept any deviation to the Percentage of Work requirements described in the DoW solicitation. Model your POW before subcontracting RF front-end, antenna, or embedded processing work.
Is the Company Commercialization Report evaluated?
The document conflicts with itself. The Phase I Proposal Guidelines state that CCR information will be considered by OSW-Reliance 21 during proposal evaluations. The Direct to Phase II Proposal Guidelines state that it will not be considered by "SCO," which appears to be residual text from another organization's instructions. Complete the CCR carefully either way, and raise the discrepancy through DSIP Topic Q&A if it matters to you.
What must the commercialization strategy address?
Five specific questions, in no more than 2 pages counting toward the 15-page Phase II technical proposal limit. What is the first product this technology will go into. Who will be your customers and what is your estimate of the market size. How much funding will you need to bring the technology to market and how will you raise those funds. Does your company contain marketing expertise and if not how do you intend to bring it in. Who are your competitors and what is your price or quality advantage.
How do I request TABA?
Using the SBIR/STTR TABA Request Form, included in Volume 5 of the DSIP submission. OSW will not accept TABA requests that do not use the form or that are not submitted in Volume 5.
What optional documents help?
Letters of support from prospective transition stakeholders within DEVCOM C5ISR Center, PAE Maneuver Ground, PAE Maneuver Air, CPE Autonomy, the Naval Research Laboratory, or the Air Force Research Laboratory. For this topic DEVCOM C5ISR Center is the most natural fit. A Data Management Plan addressing provenance, licensing, and protection of pre-training and government-furnished data is also encouraged and is directly relevant if your signal processing uses trained models.
Who evaluates my proposal?
Government technical evaluators from Army DEVCOM C5ISR Center, Army DEVCOM Army Research Lab, the Naval Research Laboratory, and the Air Force Research Laboratory may participate. Non-government support contractors may assist with administrative handling under a non-disclosure agreement but do not participate in selection decisions.
When will I hear back?
Within 90 days of the closing date of the topic, which is approximately January 19, 2027. Notifications go through DSIP to both the Corporate Official and the Principal Investigator listed on the proposal.
Does Phase II require a multi-service transition plan?
Yes. Phase II efforts under this release shall include a transition plan addressing at least two of the three Services. Phase II contracting actions are anticipated to be firm-fixed-price or cost-plus-fixed-fee at the discretion of the Contracting Officer.
Who is the technical point of contact?
The release strongly encourages engaging the Technical Point of Contact listed in the topic description during pre-release, but no TPOC appears in the DV025 description or in any of the four topic descriptions in this release. Use DSIP Topic Q&A, and send administrative questions to osd.pentagon.ousd-atl.mbx.communities-of-interest@mail.mil.
What is the commercial market?
Low-cost air traffic monitoring, counter-unmanned aircraft surveillance for critical infrastructure, and general airspace monitoring where adding active RF spectrum clutter is undesirable or prohibited. The regulatory advantage is real: a receive-only sensor needs no transmit authorization, which removes the main obstacle to deploying radar at airports, stadiums, substations, and similar sites.
Positioning Advice for Companies Considering This Topic
Audit your feasibility provenance before you decide on the DP2 path. This is the single most important thing on this topic. Feasibility documentation cannot be based upon or logically extend from any prior or ongoing federally funded SBIR or STTR work, and a proposal that fails the feasibility bar is not evaluated at all. Trace every result you intend to cite. Internally funded, privately funded, non-SBIR government contract, and commercial product work are all cleaner ground. If your passive radar hardware came out of a prior SBIR, seriously consider the Phase I path instead.
Make multi-channel synchronization the centerpiece. The topic tells you exactly what existing systems lack: tightly synchronized, multi-channel receivers for direct reference signal acquisition, spatial processing, and clutter cancellation. Achieving channel-to-channel phase coherence at attritable cost is the hard problem. Lead with your approach to it, with numbers on phase stability and the cost of the components that deliver it.
Name your X-band illuminators and defend them. This is where most proposals will be weakest. X-band is not the broadcast-illuminator regime, so you must say what you intend to exploit, whether other radars, satellite downlinks, or communications systems, and address availability, geometry, bandwidth, and what happens in a contested environment where the adversary's emissions are both your illuminator and a thing they may turn off. Treating illuminator availability as an assumption rather than an analysis is the most likely fatal weakness.
Take "shall not transmit any RF energy" literally and completely. Address unintentional emissions from local oscillators, clocks, and digital processing, not just the absence of a transmitter. An attritable sensor whose digital section radiates is not covert, and a reviewer thinking about survivability in an electronic warfare environment will notice if you only address the obvious reading.
Show the cost model, not a cost claim. Validating attritable unit cost is a stated Phase II requirement. A bill of materials at projected volume, with the receiver, antenna, and processing broken out, is far more persuasive than a target price. It also forces the design discipline the topic is asking for.
Budget the SAR and GMTI processing honestly against the platform. Both modes on Group 1 or 2 power and thermal budgets, in real time, producing actionable outputs, is a demanding computational claim. State your processing architecture, the operations per second, the power draw, and what you trade to fit. The Phase I language explicitly asks for algorithms that work under constrained computational limits, so acknowledging the constraint is expected rather than a weakness.
Write the platform integration story concretely. Group 1 or 2 UAS, loitering munitions, and unattended ground sensors are three different mechanical, thermal, and interface problems. Pick a primary and name it, ideally an actual platform, and show the mass, volume, and power budget against it.
Lead the commercial case with spectrum regulation. A receive-only sensor needs no transmit authorization. That single fact is why counter-drone and airspace monitoring at airports, stadiums, prisons, substations, and data centers is a reachable market for this technology and not for active radar. The topic names the advantage itself. Build the market size estimate on it.
Get a DEVCOM C5ISR letter of support. Letters are optional but encouraged, C5ISR is on the named list, it is the Army's sensors and electronic warfare organization, and its evaluators may be reviewing your proposal. Launched effects is a named Phase III transition target with an actual program behind it.
Plan the DP2 page budget before drafting. Five pages of feasibility, thirteen pages of technical proposal, two pages of commercialization, with all figures, tables, charts, and references inside the limits and no appendices evaluated. For a system with two radar modes, a coherent receiver, an antenna, edge processing, and a cost model, page discipline is a real design task.
Answer the five commercialization questions as five answers. They are enumerated in the instructions and a reviewer will look for each. First product, customers and market size, funding required and how raised, marketing expertise, competitors and your advantage. Do not bury them in a narrative.
Cite the real passive radar literature yourself. The topic cites only two textbooks, which means it gives you no scaffolding and you carry the full burden of demonstrating awareness of the state of the art, which the Related Work section explicitly requires. Bring the bistatic and passive coherent location literature to the proposal.
Be careful what you write about adversary systems. Classified proposals are not accepted and including classified data may make your proposal non-responsive. On a topic about surviving adversary electronic warfare and exploiting specific X-band sources, keep the unclassified proposal unclassified and note where a classified annex or a cleared discussion would follow in Phase II.
Model Percentage of Work first. No deviations are accepted, and radar development invites subcontracting the RF front end, the antenna, or the embedded software. Run the calculation before you commit to a team structure.
