Compact Passive Radar

• Added six questions about Phase I and Phase II execution: whether Phase I lab hardware must meet the proposed expendable-system SWaP-C targets; whether offline processing and commercial evaluation boards are acceptable; whether a reduced channel count can demonstrate feasibility; who provides the Phase II illuminator and test range; and which Phase I deliverables must be submitted.
• No answers to these six new questions are included in the updated text. Applicants should treat these points as unresolved and avoid assuming that lab-scale hardware, offline processing, or Government-provided test resources will be accepted or available.
• The earlier waveform, illuminator, synchronization, motion compensation, antenna, polarization, communications, and X-band questions and answers are retained under new numbering.

Q&A Added: Seven detailed answers to Q1 replace previous single answer

Q1 now has granular guidance on seven sub-topics (previously one combined answer):

• Waveform approach: Both cooperative and noncooperative methods acceptable; justify your selection
• MIMO/beam assumptions: Do not assume noncooperative transmitter is MIMO or beams both receiver and target; define your illuminator geometry
• Timing synchronization: GNSS-based or advanced methods both acceptable; justify required coherence and accuracy (clarifies solicitation wording was not stating GNSS is insufficient)
• Motion compensation: Address estimation and compensation sufficient for your proposed SAR/GMTI performance (softens prior implication that real-time compensation is required)
• Antenna configuration: Your choice; justify based on performance, integration, and SWaP-C
• Polarization: No preference; select and justify based on illuminator, environment, targets, and SWaP-C
• Communications dependency: If required by your design, identify as dependency with type, interface, availability, performance, and SWaP-C impacts

Impact: Applicants now have explicit flexibility on multiple design choices (waveform, antenna type, polarization, sync method) with clear expectation to justify assumptions rather than meet unstated government preferences.

New Q&A added with 7 specific technical clarifications:

• Waveform knowledge: Confirms noncooperative (unknown) waveforms are in scope; MIMO beam geometry not specified
• Timing synchronization: Advanced approaches beyond GNSS are explicitly in scope
• Motion compensation: Real-time adaptation for Group 1&2 UAS platform motion is expected
• Antenna & polarization: No preferred antenna type or polarization mandated—offerors have design freedom
• Inter-platform communications: Clarifies whether illuminator-receiver data-link is part of the design requirement (answer pending in original Q&A structure)

Why it matters: The new Q1 reveals that applicants have flexibility on antenna design and polarization but must plan for active real-time motion compensation on smaller UAS platforms and justify timing methods beyond basic GNSS. The inter-platform comms question signals potential complexity in coordinating between separate illuminator and receiver platforms that was not explicitly addressed before.

Description information changed.

Description information changed.

Status changed from status: Pre-Release to status: Open.

New opportunity: Compact Passive Radar