ADR-171: Drone Swarm Benchmarking & Evaluation Methodology — Metrics, Leaderboards, and Statistical Rigor

Field	Value
Status	Accepted (peer-reviewed 2026-05-30)
Date	2026-05-30
Deciders	ruv
Relates to	ADR-148 (ruview-swarm), ADR-147 (OccWorld), ADR-146 (RF encoder), ADR-028 (witness)

Companion to ADR-148. ADR-148 shipped the swarm and 5 criterion micro-benchmarks plus a SotaComparison against Wi2SAR. This ADR defines how we evaluate the swarm rigorously — what metrics, what statistics, what baselines, and an honest account of which external leaderboards do and do not apply.

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1. Context

ADR-148's ruview-swarm reports performance via five criterion micro-benchmarks and a single SotaComparison (localization 1.732 m vs Wi2SAR 5 m; coverage ~223 s vs 810 s). These numbers are internally valid but insufficient as scientific claims:

• The criterion figures (3.3 µs MARL inference, 43 µs RRT-APF, 54 ns fusion, 248 µs PPO step) measure wall-clock latency, not policy quality or coverage/localization quality.
• The 1.732 m localization comes from a single synthetic geometry (3 drones at 120° around a known point), not a distribution of victim positions under realistic noise.
• The 223 s coverage is an analytic estimate (estimate_coverage_time_secs()), not an episode rollout.
• All numbers are single-run point estimates. The MARL reproducibility literature (Henderson 2018; Agarwal 2021; Gorsane 2022) shows single/few-seed point estimates routinely flip algorithm rankings and overstate gains.

We need a defined, reproducible evaluation methodology before any "beats SOTA" claim can survive external review, and an honest position on external leaderboards.

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2. Decision

Adopt a two-tier evaluation methodology:

1. Micro-benchmarks (criterion) — keep for compute-latency regression gating only. Explicitly labeled as latency, never as quality.
2. Domain evaluation harness — a seeded, multi-run, statistically-reported harness producing SAR metrics (localization CEP, coverage, detection rate) and MARL metrics (IQM return, probability-of-improvement) over ≥10 seeds with 95% stratified-bootstrap confidence intervals, against ≥3 baselines, following the Agarwal/Gorsane standard.

Do not claim leaderboard standing — no public leaderboard accepts drone-swarm CSI-SAR submissions. Comparisons to Wi2SAR are paper-to-paper, labeled as such, acknowledging the sensing-modality difference (RSS bearing vs CSI multi-view fusion).

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3. External Leaderboard Landscape — Honest Assessment

There is no public, externally-administered leaderboard that accepts a drone-swarm, CSI-based, multi-view SAR system. This is a research niche; comparison is paper-to-paper. The adjacent options and their fit:

Benchmark / Leaderboard	Domain	Live submission?	Fit for ruview-swarm
Wi2SAR (arxiv 2604.09115)	Drone WiFi SAR	No (paper)	Direct baseline — paper-to-paper only; RSS bearing ≠ CSI fusion
MARL4DRP (Springer 2023)	Drone routing MARL	No	Closest drone-MARL benchmark; would need a routing→coverage adapter
CSI-Bench (NeurIPS 2025)	Static WiFi sensing	Splits + paper baselines	Adjacent (localization task) but no moving-sensor/multi-view fusion
SMAC / SMACv2	StarCraft cooperative MARL	No live LB	Structural analogy (CTDE) only; combat task, not coverage
PettingZoo MPE (Simple Spread)	2D cooperative particles	No	Cheap MARL correctness check, no physics/CSI
Melting Pot	Social-dynamics MARL	Closed (NeurIPS '24)	Not applicable
MAMuJoCo / Hanabi / GRF / Overcooked	Various cooperative MARL	No live LB	Not applicable
OmniDrones / gym-pybullet-drones / Pegasus	Drone-control sim platforms	No (platforms)	Training infrastructure, not leaderboards; no CSI layer

Conclusion: We will (a) keep Wi2SAR as the cited paper baseline, (b) optionally build a MARL4DRP/MPE adapter to post a recognized cooperative-MARL number (tangential to SAR), and (c) not represent any internal number as a leaderboard placement.

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4. Evaluation Metrics

4.1 SAR Domain Metrics (primary — comparable to Wi2SAR)

Metric	Definition	Reporting
Localization CEP50	Median horizontal error, fused victim position vs ground truth	m, 95% CI
Localization CEP95	95th-percentile horizontal error	m
GDOP	Geometric Dilution of Precision of the contributing-drone constellation at detection time	dimensionless (tracked per detection)
Coverage rate @ T	Fraction of area scanned ≥1× within T=240 s	%, 95% CI
Coverage time to 95%	Time to scan 95% of bounded area	s, mean ± CI
Time-to-first-detection	Mission start → first confident detection (conf > 0.85)	s, 95% CI
Detection rate	P(detected | victim present) per mission	%, 95% CI
False-alarm rate	P(confident detection | no victim)	%, 95% CI
Collision rate	Collisions (d < 1.5 m) per mission	count/mission
Overlap ratio	Fraction of path re-covering scanned cells	%

4.2 MARL Policy-Quality Metrics

Metric	Definition
IQM episodic return	Interquartile mean over 10 seeds × 50 eval episodes (Agarwal 2021)
Probability of improvement	P(MAPPO return > IPPO return) on a random episode
Optimality gap	Expected gap to a defined reference performance
Performance profile	Fraction of (seed, episode) with localization error < τ, plotted vs τ ∈ [0,10] m
Sample efficiency	Return vs training steps (curve, not point)

4.3 Micro-benchmarks (criterion — latency only)

Retained from ADR-148, labeled as compute latency, not quality: marl_actor_inference 3.3 µs · rrt_apf_100iter 43 µs · multiview_fusion_3drones 54 ns · demo_coverage_estimate 100 ps · ppo_update_64transitions 248 µs. Purpose: prove the control loop has no compute bottleneck (all ≪ the 10 ms / 100 Hz budget) and gate performance regressions. They are not evidence of policy or localization quality.

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5. Statistical Protocol (Agarwal 2021 / Gorsane 2022)

Requirement	Standard adopted
Seeds per condition	≥10 training runs from distinct seeds
Evaluation episodes	50 fixed, versioned episodes per trained policy (10 victim layouts × 5 CSI-noise levels)
Aggregate metric	IQM (not mean, not median) + performance profiles
Confidence intervals	95% stratified bootstrap, 1,000 resamples
Baselines (≥3)	Random walk (lower bound), Boustrophedon+manual-triangulation (heuristic), IPPO (no shared critic)
Reproducibility	Versioned YAML config (drone count, area, victims, CSI σ amplitude / κ phase, wind, packet loss) + all seeds committed with results

Rationale: Henderson et al. (2018) found ≤5-seed point estimates flip rankings; Agarwal et al. (2021, NeurIPS Outstanding Paper) show IQM needs ~10 runs for the statistical power that the median needs ~200 runs for; Gorsane et al. (2022) made ≥10 seeds + IQM + stratified CIs the cooperative-MARL standard. rliable (google-research/rliable) is the reference impl.

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6. Reproducibility Harness (evals/)

A new evaluation harness (separate from criterion micro-benchmarks):

1. Seeded episodes — every episode, noise perturbation, and training run seeded from a versioned config; seeds committed with results (no Date.now()/unseeded RNG).
2. Per-episode logging — coverage %, localization error, GDOP, time-to-first-detection, collisions, detection binary → JSONL (reuses the ADR-148 telemetry schema).
3. Aggregation — IQM ± 95% stratified-bootstrap CI across the 10-seed × 50-episode matrix.
4. Baseline sweep — random / boustrophedon-heuristic / IPPO / MAPPO, so probability-of-improvement and performance profiles are computable.
5. Output — committed evals/RESULTS.md: a reproducible internal leaderboard ranking our 6 flight patterns × learning patterns on the SAR metrics, plus the Wi2SAR paper row.

This RESULTS.md is the real, defensible "leaderboard" for this system — patterns ranked against each other and the cited baseline, reproducibly, with CIs.

6.1 Dual-stage pipeline (compute-cost mitigation)

The full matrix is 10 seeds × 50 episodes × ≥4 conditions = ≥2,000 rollouts per policy. Running each rollout against the OccWorld 3D prior (ADR-147, ~375 ms/inference) would melt the L4 / RTX 5080 budget. Split evaluation into two stages:

• Stage 1 — Kinematic (fast, full matrix). Stripped vector environment; OccWorld paths pre-cached or treated as static analytical volumes. Produces episodic return, IQM, sample-efficiency curves, coverage %, GDOP, localization error over the full 10-seed matrix.
• Stage 2 — High-fidelity physics (sub-sampled). Take the 3 median seeds (by Stage-1 IQM) into Gazebo + PX4 SITL with full CSI phase/amplitude noise. Extracts false-alarm rate and collision rate under realistic dynamics (heading-rate limits, APF repulsion, motor response) that the kinematic sim omits.

Stage 1 is CI-runnable today; Stage 2 requires the Gazebo/PX4 SITL bring-up (follow-on).

6.2 Noise sweep (coherence-gate threshold)

The config generator systematically varies the two CSI noise parameters:

• σ — Gaussian amplitude noise (CSI magnitude)
• κ — von Mises phase concentration (lower κ = noisier phase)

Sweeping (σ, κ) isolates the exact environmental threshold where CrossViewpointAttention (ADR-016) drops out of its coherence gate (coherence_gate.rs Accept → PredictOnly/Reject, ADR-135). This finds the operating envelope, not just a single-point accuracy.

6.3 GDOP tracking

Localization accuracy is meaningless without the constellation geometry that produced it. The harness records GDOP per detection: 3 drones in a ~120° constellation give the √3 ≈ 1.73× CRLB improvement; 3 collinear drones degrade toward the single-view Cramer-Rao limit (~2.9 m). Reporting localization error stratified by GDOP band prevents the headline number from being a best-case geometric artifact.

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7. Evidence Grading of Current ADR-148 Numbers

Claim	Grade	Why
criterion latencies (3.3 µs / 43 µs / 54 ns / 248 µs)	High	Deterministic compute, hardware-specific, reproducible
Wi2SAR baseline (5 m, 160k m²/13.5 min)	High	Published field trial, open source
1.732 m 3-view localization	Low–Medium	Single synthetic geometry; no noise distribution; CRLB predicts ~2.9 m for N=3
223 s 4-drone coverage	Low	Analytic estimate, not an episode rollout
"beats SOTA"	Directional only	Valid as paper-to-paper direction; not leaderboard, not multi-seed

The √N multi-view scaling claim is theoretically sound (CRLB: σ ∝ 1/√(N·SNR); N=3 → √3 ≈ 1.73× improvement), but the measured 1.732 m must be reproduced over a victim-position and noise distribution before it is defensible.

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8. Consequences

Positive

• Converts scattered numbers into a reproducible, statistically-honest evaluation.
• The RESULTS.md internal leaderboard ranks the 6 flight × 4 learning patterns fairly.
• Aligns with the recognized MARL evaluation standard (IQM + stratified CIs + ≥10 seeds).
• Honest external-leaderboard position avoids overclaiming.

Costs / Risks

• ≥10 seeds × 50 episodes × N patterns × N baselines is a real compute cost — this is where the ADR-148 GCP L4 / local RTX 5080 training budget is actually spent.
• Requires the MARL policy to be trained to convergence first (the ADR-148 5-episode CPU run shows decreasing value_loss, not convergence).
• Coverage/localization must move from analytic estimate / synthetic geometry to episode rollouts under realistic CSI noise before headline numbers are republished.

Open issues → follow-on work

1. Train MAPPO/IPPO to convergence (M4 follow-on) before running the eval harness.
2. Build the seeded evals/ harness + RESULTS.md generator.
3. Optional: MARL4DRP or MPE Simple-Spread adapter for a recognized cooperative-MARL number.
4. Re-state ADR-148 §14 headline numbers with CIs once the harness has run.

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9. Research Notes & References

Compiled by ruflo-goals:deep-researcher (2026-05-30). Full landscape in the agent record.

MARL evaluation rigor

• Henderson et al., "Deep RL That Matters", arxiv 1709.06560 — ≤5-seed estimates flip rankings
• Agarwal et al., "Deep RL at the Edge of the Statistical Precipice", NeurIPS 2021, arxiv 2108.13264 — IQM, performance profiles, stratified bootstrap; rliable
• Gorsane et al., "Standardised Evaluation Protocol for Cooperative MARL", NeurIPS 2022, arxiv 2209.10485 — ≥10 seeds + IQM standard
• BenchMARL, arxiv 2312.01472 — operationalizes the above

Cooperative-MARL benchmarks

• SMACv2, arxiv 2212.07489 · PettingZoo MPE (Farama) · Melting Pot (DeepMind, NeurIPS 2024 contest) · MAMuJoCo (Gymnasium-Robotics) · MARL4DRP, Springer 2023 (closest drone-MARL)

Drone-sim platforms

• gym-pybullet-drones, arxiv 2103.02142 · OmniDrones, IEEE RA-L 2024 · Pegasus, arxiv 2307.05263 · Flightmare (IROS 2021) · AirSim (discontinued 2022) · Crazyswarm2

SAR / coverage / CSI sensing

• Wi2SAR, arxiv 2604.09115 (direct baseline: 5 m, 160k m²/13.5 min, 18.4° median AoA)
• CSI-Bench, NeurIPS 2025, arxiv 2505.21866 (461 h WiFi sensing, localization task)
• Coverage path planning, PMC9571681 (boustrophedon ~5% faster than spiral)
• Bio-inspired SAR, Nature s41598-025-33223-z (PSO > Levy/ACO on exploration score)
• CRLB for CSI localization, IEEE 8110647 (σ ∝ 1/√(N·SNR))

Tooling

• criterion.rs known limitations — wall-clock only, not algorithmic quality
• rliable, github.com/google-research/rliable

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ADR authored with research support from ruflo-goals:deep-researcher (2026-05-30). Companion to ADR-148. Defines the evaluation methodology that the ADR-148 headline numbers must satisfy before being republished as defensible claims.