3D True PN Engagement

PARITYS0 · dim 6

No clear winner. The survival gap is under 10 percentage points and the balanced-score gap is under 0.05, so neither SolvSRK nor the best baseline clears the win threshold. Either works — choose on cost, licensing, or integration effort. All verdicts →

3D engagement with azimuth and elevation LOS rates. True PN (N=3) in both planes against straight-line target.

Guidance & interception

Problem definition

Zarchan Ch. 3 (3D engagement geometry)

Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.

Show canonical RHS excerpt
def rhs(t, y):
    rx, ry, rz = y[0], y[1], y[2]
    vx_i, vy_i, vz_i = y[3], y[4], y[5]

    d = np.empty(6)

    R = np.sqrt(rx * rx + ry * ry + rz * rz)
    if R < _RANGE_GUARD:
        d[:] = 0.0
        return d

    vx_rel = vx_i - vtx
    vy_rel = vy_i - vty
    vz_rel = vz_i - vtz

    R_dot = (rx * vx_rel + ry * vy_rel + rz * vz_rel) / R
    V_c = -R_dot

    R2 = R * R
    omega_x = (ry * vz_rel - rz * vy_rel) / R2
    omega_y = (rz * vx_rel - rx * vz_rel) / R2
    omega_z = (rx * vy_rel - ry * vx_rel) / R2

    omega_mag = np.sqrt(omega_x**2 + omega_y**2 + omega_z**2)
    if omega_mag > _LOS_RATE_CLAMP:
        scale = _LOS_RATE_CLAMP / omega_mag
        omega_x *= scale
        omega_y *= scale
        omega_z *= scale

    a_x = N * V_c * omega_x
    a_y = N * V_c * omega_y
    a_z = N * V_c * omega_z

    d[0] = vx_rel
    d[1] = vy_rel
    d[2] = vz_rel
    d[3] = a_x
    d[4] = a_y
    d[5] = a_z

    return d
Parameters
  • N = 3
  • _LOS_RATE_CLAMP = 0.5
  • _RANGE_GUARD = 0.1
  • vtx = 200
  • vty = 30
  • vtz = -10
Initial condition
y(0) = [5000, 2000, 1000, -250, 0, 0]
Horizon
t ∈ [0, 25]

Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.

Fingerprint

Spread: extreme

Default noise: low

Recommendation snapshot

Clean best: Vern9

Noisy best: SciPy LSODA

Coverage

14 solver arms · clean + 5 noise levels

Ranked on survival, precision, and speed

Versions & freeze

Methodology →
Freeze
2026-08-13
libsolvsrk
2.3.0
SciPy
1.14
SUNDIALS
CVODE (bundled backend)

20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: 3D True PN Engagement (3d-true-pn-engagement)

Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.

Self-reported by Resonix Labs · not independently verified

Results matrix

Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.

Objective

Best overall trade-off of survival, precision, and speed.

Noise level

#SolverSurvivalSCDnfevWallScore
1Vern9external
100%
10.44182.81 s0.866
2SolvSRK
100%
10.31,61225 ms0.865
3SciPy RadauSciPy
100%
10.32,70835 ms0.865
4Vern7external
100%
10.05122.80 s0.858
5Tsit5external
100%
8.7618708 ms0.826
6SciPy DOP853SciPy
100%
8.53142 ms0.821
7SciPy RK45SciPy
100%
8.16384 ms0.811
8SciPy LSODASciPy
100%
7.74072 ms0.803
9SciPy RK23SciPy
100%
7.34,47537 ms0.793
10FBDFexternal
100%
7.27213.79 s0.790
11CVODE Adamsexternal
100%
7.02798 ms0.785
12SciPy BDFSciPy
100%
6.780016 ms0.778
13CVODE BDFexternal
100%
6.23689 ms0.766
14TRBDF2external
100%
4.44,9743.62 s0.723

At Clean, best balanced arm is Vern9 · SolvSRK survival 100%, SCD 10.3.

Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →

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Cite this page

Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.

@misc{resonix_evidence_3d_true_pn_engagement_2026,
  title        = {Resonix Evidence Portal: 3D True PN Engagement},
  author       = {{Resonix Labs (Canada) Inc.}},
  year         = {2026},
  howpublished = {\url{https://resonix.tech/evidence/problems/3d-true-pn-engagement}},
  note         = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}

Related

TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels

Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology

Self-reported by Resonix Labs · not independently verified · Verification status