CLOE — MIRA-SAR — Miniature SAR for GNSS-denied Navigation

Executive summary

Key indicators across requirements, verification and traceability.

23

Requirements

91%

Accepted requirements

16 / 21

IVV tests passed

91%

Requirement coverage

176

Traceability links

8 / 8

Open technical issues

Traceability state

21/23 requirements covered by at least one test (91%), 14 fully verified (60%), 16/21 tests passed, 0 orphan test(s).

Req	Requirement	Status	Cov.	Verifying tests
REQ-001	The payload shall provide an absolute horizontal position fix without GNSS with an accuracy of CEP95…	Accepted	✓	PASS Absolute position fix accuracy against surveyed ground truth… [Qualification campaign] todo Correlation accuracy over varied terrain (urban vs rural). [Flight test campaign]
REQ-002	The payload shall bound the host inertial navigation horizontal drift to ≤ 15 m over any 60 s coasti…	Accepted	✓	PASS INS coasting drift characterization between fixes. [Qualification campaign] todo GNSS-denied endurance flight: 30 min navigation with GNSS of… [Flight test campaign]
REQ-003	The payload shall deliver position fixes at a rate ≥ 0.1 Hz (one fix every 10 s) under nominal imagi…	Accepted	✓✓	PASS In-flight fix rate under nominal terrain. [Flight test campaign]
REQ-004	The payload shall sustain GNSS-denied navigation for ≥ 30 min continuous while remaining within the …	Accepted	✓	todo GNSS-denied endurance flight: 30 min navigation with GNSS of… [Flight test campaign]
REQ-005	Time to first valid fix after entering imaging mode shall be ≤ 90 s.	Analysis	✓✓	PASS Time to first fix after entering imaging mode. [Qualification campaign] PASS In-flight cold-start time to first fix. [Flight test campaign]
REQ-006	The payload shall detect GNSS denial or spoofing and switch to SAR-aided navigation within 5 s of on…	Accepted	✓✓	PASS Live GNSS denial detection latency. [Flight test campaign]
REQ-007	The SAR sensor shall achieve a ground resolution ≤ 1.0 m (range) × 1.0 m (azimuth).	Accepted	✓✓	PASS SAR resolution measurement using corner reflectors. [Qualification campaign]
REQ-008	The payload shall operate over a height-above-ground-level envelope of 150 m to 1500 m.	Accepted	✓	todo Altitude & swath envelope flight check. [Flight test campaign]
REQ-009	The imaged swath width shall be ≥ 600 m at 1000 m AGL.	Accepted	✓	todo Altitude & swath envelope flight check. [Flight test campaign]
REQ-010	The sensor shall operate in Ku-band centred at 16.7 GHz with a transmit bandwidth ≥ 300 MHz.	Accepted	✓✓	PASS SAR resolution measurement using corner reflectors. [Qualification campaign] PASS RF emission, EIRP limit and ground inhibit. [Qualification campaign]
REQ-011	The payload shall store on board ≥ 50 000 km² of geo-referenced reference imagery for scene matching…	Accepted	✓✓	PASS Reference map storage capacity load test. [Qualification campaign]
REQ-012	The correlation of a formed SAR image against the reference map shall complete within ≤ 2 s (end-to-…	Accepted	✓✓	PASS Correlation latency benchmark. [Qualification campaign]
REQ-013	The payload shall gate and reject ambiguous or false correlation fixes such that no position jump > …	Accepted	✓✓	PASS False-fix gating with injected ambiguous scenes. [Qualification campaign]
REQ-014	The total payload mass shall be ≤ 2.5 kg.	Accepted	✓✓	PASS Payload mass measurement. [Qualification campaign]
REQ-015	The payload shall draw an average electrical power ≤ 80 W from the host 24 V DC bus.	Accepted	✓✓	PASS Average power consumption on 24 V bus. [Qualification campaign]
REQ-016	The payload shall output a navigation correction to the host autopilot over CAN/serial at a rate ≥ 2…	Accepted	✓✓	PASS Navigation correction output to autopilot in flight. [Flight test campaign]
REQ-017	The payload shall operate over a temperature range of −20 °C to +55 °C.	Accepted	✓	todo Thermal operating range qualification. [Qualification campaign]
REQ-101	The payload shall operate only under a valid experimental frequency authorization for its Ku-band em…	Accepted	✗	No test
REQ-102	The payload shall limit its radiated EIRP to the authorized maximum and shall inhibit RF transmissio…	Accepted	✓✓	PASS RF emission, EIRP limit and ground inhibit. [Qualification campaign]
REQ-103	Reference map data shall be encrypted at rest (AES-256) and shall be securely erased within 5 s upon…	Accepted	✓✓	PASS Map encryption at rest and secure erase. [Qualification campaign]
REQ-104	Stored imagery and correlation data shall be handled in accordance with applicable export-control ru…	Accepted	✗	No test
REQ-105	On any detected internal fault the payload shall flag the navigation solution as invalid and shall n…	Accepted	✓✓	PASS Built-in test and fault → invalid-fix flag. [Qualification campaign]
REQ-106	The payload shall be electromagnetically compatible with the host UAV avionics per RTCA DO-160 secti…	Analysis	✓	todo EMC emissions per DO-160 section 21. [Qualification campaign]

Issues & checks

Rule-based controls on the traceability graph.

2 requirement(s) without any IVV test
0 requirement(s) with no verification method
0 requirement(s) with quality warnings (wording, atomicity, “shall”…)
0 test(s) not linked to any requirement
3 open critical/blocking technical issue(s)

Requirements

Safety, RF & export-control requirements — 7 item(s)

Regulatory, RF-spectrum, data-protection and fail-safe requirements for the SAR payload.

ID	Requirement	Prio.	Verif.	Status
—	Safety, RF & export-control requirements Regulatory, RF-spectrum, data-protection and fail-safe constraints applicable to a SAR emitter carrying potentially sensitive reference imagery on an uncrewed platform.
REQ-101	The payload shall operate only under a valid experimental frequency authorization for its Ku-band emission and shall not radiate outside the authorized band.	Must	Inspection	Accepted
REQ-102	The payload shall limit its radiated EIRP to the authorized maximum and shall inhibit RF transmission while on the ground (weight-on-wheels / safe interlock).	Must	Test	Accepted
REQ-103	Reference map data shall be encrypted at rest (AES-256) and shall be securely erased within 5 s upon a tamper or authenticated erase command.	Must	Test	Accepted
REQ-104	Stored imagery and correlation data shall be handled in accordance with applicable export-control rules (ITAR/EAR) for geospatial intelligence.	Must	Inspection	Accepted
REQ-105	On any detected internal fault the payload shall flag the navigation solution as invalid and shall never output a silent erroneous fix (fail-safe, no misleading information).	Must	Test	Accepted
REQ-106	The payload shall be electromagnetically compatible with the host UAV avionics per RTCA DO-160 section 21 (emissions).	Should	Test	Analysis

System requirements — 22 item(s)

Top-level functional and performance requirements for the MIRA-SAR GNSS-denied navigation payload.

ID	Requirement	Prio.	Verif.	Status
—	System requirements Functional and performance requirements for the MIRA-SAR map-aided inertial navigation payload — a miniature Ku-band SAR sensor that geo-locates the host UAV by correlating in-flight SAR imagery with onboard satellite reference maps, with no GNSS.
—	Navigation performance
REQ-001	The payload shall provide an absolute horizontal position fix without GNSS with an accuracy of CEP95 ≤ 10 m over correlatable terrain.	Must	Test	Accepted
REQ-002	The payload shall bound the host inertial navigation horizontal drift to ≤ 15 m over any 60 s coasting interval between two valid fixes.	Must	Test	Accepted
REQ-003	The payload shall deliver position fixes at a rate ≥ 0.1 Hz (one fix every 10 s) under nominal imaging conditions.	Must	Test	Accepted
REQ-004	The payload shall sustain GNSS-denied navigation for ≥ 30 min continuous while remaining within the drift budget of REQ-002.	Must	Test	Accepted
REQ-005	Time to first valid fix after entering imaging mode shall be ≤ 90 s.	Should	Test	Analysis
REQ-006	The payload shall detect GNSS denial or spoofing and switch to SAR-aided navigation within 5 s of onset.	Must	Test	Accepted
—	SAR sensor
REQ-007	The SAR sensor shall achieve a ground resolution ≤ 1.0 m (range) × 1.0 m (azimuth).	Must	Test	Accepted
REQ-008	The payload shall operate over a height-above-ground-level envelope of 150 m to 1500 m.	Must	Test	Accepted
REQ-009	The imaged swath width shall be ≥ 600 m at 1000 m AGL.	Should	Test	Accepted
REQ-010	The sensor shall operate in Ku-band centred at 16.7 GHz with a transmit bandwidth ≥ 300 MHz.	Must	Test	Accepted
—	Reference maps & correlation
REQ-011	The payload shall store on board ≥ 50 000 km² of geo-referenced reference imagery for scene matching.	Must	Test	Accepted
REQ-012	The correlation of a formed SAR image against the reference map shall complete within ≤ 2 s (end-to-end latency).	Must	Test	Accepted
REQ-013	The payload shall gate and reject ambiguous or false correlation fixes such that no position jump > 30 m is injected into the navigation solution.	Must	Test	Accepted
—	SWaP & host interface
REQ-014	The total payload mass shall be ≤ 2.5 kg.	Must	Test	Accepted
REQ-015	The payload shall draw an average electrical power ≤ 80 W from the host 24 V DC bus.	Must	Test	Accepted
REQ-016	The payload shall output a navigation correction to the host autopilot over CAN/serial at a rate ≥ 20 Hz.	Must	Test	Accepted
REQ-017	The payload shall operate over a temperature range of −20 °C to +55 °C.	Should	Test	Accepted

MBSE models

Operational analysis — Operational analysis · 13 element(s)

Operational context of map-aided navigation in a GNSS-denied / contested environment: who needs an absolute position without GNSS, and through which activities.

System functions — Functional need (system analysis) · 19 element(s)

Functional breakdown of the MIRA-SAR payload: from SAR acquisition through scene-matching correlation to inertial fusion and the navigation solution delivered to the host autopilot.

Logical architecture — Logical architecture · 29 element(s)

Logical decomposition of MIRA-SAR into subsystems and the logical functions they host, each realizing one or more system functions.

Physical architecture — Physical architecture · 22 element(s)

Physical implementation of MIRA-SAR: the on-board assemblies and components realizing the logical subsystems, sized for a ≤ 2.5 kg drone payload.

Navigation aiding states — States & modes · 6 element(s)

Navigation integrity automaton: passthrough when GNSS is available, transition to SAR-aided fixing on denial, and coasting / degraded behaviour when correlation is unavailable.

Payload operating modes — States & modes · 8 element(s)

MIRA-SAR payload mode automaton: power-up BIT, calibration, SAR imaging, and the safety / data-protection transitions (fault, secure erase).

IVV test campaigns

Flight test campaign — 4/7 passed

In-flight verification of GNSS-denied navigation performance, fix rate, denial detection and autopilot integration.

Type	Description	Expected result	Result
Test	GNSS-denied endurance flight: 30 min navigation with GNSS off.	Within drift budget for full duration.	not passed
Test	In-flight fix rate under nominal terrain.	Fix rate ≥ 0.1 Hz.	PASS
Test	Live GNSS denial detection latency.	Switch within 5 s.	PASS
Test	Altitude & swath envelope flight check.	Operational across envelope; swath ≥ 600 m at 1000 m.	not passed
Test	Correlation accuracy over varied terrain (urban vs rural).	CEP95 ≤ 10 m on correlatable terrain.	not passed
Test	Navigation correction output to autopilot in flight.	Correction at ≥ 20 Hz, accepted by autopilot.	PASS
Test	In-flight cold-start time to first fix.	TTFF ≤ 90 s.	PASS

Qualification campaign — 12/14 passed

Bench, lab and environmental verification of the MIRA-SAR payload against the system, safety and RF requirements.

Type	Description	Expected result	Result
Test	SAR resolution measurement using corner reflectors.	Resolution ≤ 1.0 m × 1.0 m.	PASS
Test	Absolute position fix accuracy against surveyed ground truth (captive/lab).	CEP95 ≤ 10 m.	PASS
Test	INS coasting drift characterization between fixes.	Drift ≤ 15 m / 60 s.	PASS
Test	Time to first fix after entering imaging mode.	TTFF ≤ 90 s.	PASS
Test	Correlation latency benchmark.	Latency ≤ 2 s.	PASS
Test	Reference map storage capacity load test.	≥ 50 000 km² stored and verifiable.	PASS
Test	Average power consumption on 24 V bus.	Average ≤ 80 W.	PASS
Test	Payload mass measurement.	Mass ≤ 2.5 kg.	PASS
Test	Thermal operating range qualification.	Functional across range.	not passed
Test	RF emission, EIRP limit and ground inhibit.	Within authorization; RF inhibited on ground.	PASS
Test	Map encryption at rest and secure erase.	Encrypted; erase ≤ 5 s.	PASS
Test	Built-in test and fault → invalid-fix flag.	Fault flagged; no misleading fix.	PASS
Test	EMC emissions per DO-160 section 21.	Within DO-160 §21 limits.	not passed
Test	False-fix gating with injected ambiguous scenes.	No injected jump > 30 m.	PASS

Interfaces (ICD)

Interfaces — 7 interface(s)

ID	Interface	A	Dir.	B	Nature	Status
IF-001	Navigation correction output (payload → autopilot)	MIRA-SAR Navigation Payload	A → B	UAV autopilot	Data	Agreed
IF-002	Status & SAR image downlink (payload → GCS)	MIRA-SAR Navigation Payload	A → B	Ground control station	Data	Draft
IF-003	RF aperture interface (transceiver ↔ antenna)	Ku-band MMIC transceiver	Bidirectional	Slotted-waveguide antenna	RF	Frozen
IF-004	Reference map load interface (loader → secure store)	Ground data loader	A → B	Encrypted NVMe SSD	Data	Agreed
IF-005	Inertial data interface (IMU → processor)	Tactical-grade MEMS IMU	A → B	Navigation & Correlation Processor	Data	Agreed
IF-006	Primary power interface (UAV bus → payload)	UAV platform (host)	A → B	Power & Thermal Module	Electrical	Frozen
IF-007	Time synchronization (autopilot → payload)	UAV autopilot	A → B	MIRA-SAR Navigation Payload	Signal	Agreed

Technical issues

Technical issues — 8 issue(s)

ID	Issue	Category	Severity	Status
FT-001	Correlation fails over featureless terrain (water, dense forest, desert)	Anomaly	Critical	Open
FT-002	Drift exceeds budget at 1500 m AGL due to coarser effective resolution	Non-conformance	Major	Analyzing
FT-003	RFSoC thermal throttling reduces fix rate in warm conditions	Anomaly	Major	Open
FT-004	Urban layover & shadow degrade SAR registration accuracy	Observation	Major	Analyzing
FT-005	IMU bias instability grows after sustained rotor vibration	Anomaly	Major	Open
FT-006	Seasonal change (snow / vegetation) causes registration error vs stale maps	Observation	Minor	Resolved
FT-007	Ambiguous match produced a 40 m navigation jump before gating	Non-conformance	Blocking	Analyzing
FT-008	RF pulse current transient browns out the compute rail	Anomaly	Critical	Open