Files
micarrsim/tests/unit/beam-pattern.test.js
T

416 lines
14 KiB
JavaScript

import {
computeReceiveBeamPattern,
receiveBeamPatternDirection,
} from "/packages/acoustics-core/beam-pattern.js";
function assertNear(actual, expected, tolerance, label) {
assert(
Math.abs(actual - expected) <= tolerance,
label + ": expected " + expected + " ± " + tolerance + ", received " + actual,
);
}
function arrayFromPositions(positions) {
return {
microphones: positions.map((position, index) => ({
id: "mic-" + String(index + 1),
position,
})),
};
}
function sampleAtAngle(pattern, angleDeg) {
let bestIndex = 0;
let bestDistance = Infinity;
for (let index = 0; index < pattern.anglesDeg.length; index += 1) {
const delta = Math.abs(pattern.anglesDeg[index] - angleDeg);
const circularDistance = Math.min(delta, 360 - delta);
if (circularDistance < bestDistance) {
bestDistance = circularDistance;
bestIndex = index;
}
}
assert(bestDistance < 1e-10, "requested angle is present in sampled cut");
return pattern.responseLinear[bestIndex];
}
test("receive beam-pattern cuts use the documented right-handed axes", () => {
const cases = [
["xy", 0, [1, 0, 0]],
["xy", 90, [0, 1, 0]],
["xz", 0, [0, 0, 1]],
["xz", 90, [1, 0, 0]],
["yz", 0, [0, 0, 1]],
["yz", 90, [0, 1, 0]],
];
for (const [cut, angleDeg, expected] of cases) {
const actual = receiveBeamPatternDirection(cut, angleDeg);
actual.forEach((value, axis) =>
assertNear(value, expected[axis], 1e-12, cut + " direction axis " + axis));
}
});
test("one ideal point microphone is omnidirectional on every sampled cut", () => {
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([[12.5, -7, 3]]),
frequencyHz: 49_125,
speedOfSound: 343,
cut: "yz",
steeringAngleDeg: -35,
sampleCount: 360,
});
for (const response of pattern.responseLinear) {
assertNear(response, 1, 1e-12, "single-microphone response");
}
assertEqual(
pattern.metrics.halfPowerBeamwidth.status,
"full-circle-above-half-power",
"flat cut status",
);
assertEqual(pattern.metrics.halfPowerBeamwidth.widthDeg, null, "flat cut has no HPBW");
assert(
pattern.metrics.halfPowerBeamwidth.fullCircleAboveHalfPower,
"flat cut records the missing crossing",
);
assertEqual(
pattern.metrics.sampledLocalMaxima.peaks.length,
0,
"flat cut has no unique peaks",
);
});
test("half-wavelength two-microphone broadside cut has nulls, 60-degree HPBW, and front-back tie", () => {
const speedOfSound = 343;
const frequencyHz = 1_000;
const spacing = speedOfSound / frequencyHz / 2;
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([[-spacing / 2, 0, 0], [spacing / 2, 0, 0]]),
frequencyHz,
speedOfSound,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: 1_440,
});
assertNear(sampleAtAngle(pattern, 90), 0, 1e-12, "endfire null at +x");
assertNear(sampleAtAngle(pattern, 270), 0, 1e-12, "endfire null at -x");
assertNear(sampleAtAngle(pattern, 0), 1, 1e-12, "steered broadside response");
assertNear(sampleAtAngle(pattern, 180), 1, 1e-12, "planar front-back response");
assertEqual(
pattern.metrics.halfPowerBeamwidth.status,
"sampled-bracketed-bisection",
"HPBW status",
);
assertNear(pattern.metrics.halfPowerBeamwidth.widthDeg, 60, 1e-10, "power HPBW");
const zeroDbAngles = pattern.metrics.sampledLocalMaxima.peaks
.filter((peak) => Math.abs(peak.responseDb) < 1e-10)
.map((peak) => peak.angleDeg)
.sort((left, right) => left - right);
assertEqual(zeroDbAngles.join(","), "0,180", "front-back maxima remain tied");
assertEqual(
pattern.metrics.sampledLocalMaxima.status,
"tied-global-maxima-on-grid",
"global tie is explicit",
);
assertEqual(pattern.metrics.sampledLocalMaxima.selected, null, "tie has no selected peak");
assertEqual(
pattern.metrics.sampledLocalMaxima.globalMaximumRegions.length,
2,
"both tied regions are preserved",
);
assertNear(pattern.responseReal[Math.floor(pattern.sampleCount / 2)], 1, 1e-12, "raw real");
assertNear(pattern.responseImaginary[Math.floor(pattern.sampleCount / 2)], 0, 1e-12, "raw imaginary");
assertNear(pattern.responsePower[Math.floor(pattern.sampleCount / 2)], 1, 1e-12, "raw power");
});
test("asymmetric array preserves the receive steering sign in raw complex response", () => {
const speedOfSound = 343;
const frequencyHz = 1_000;
const quarterWavelength = speedOfSound / frequencyHz / 4;
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([
[0, 0, 0],
[quarterWavelength, 0, 0],
[3 * quarterWavelength, 0, 0],
]),
frequencyHz,
speedOfSound,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: 360,
});
const lookIndex = [...pattern.anglesDeg].findIndex((angle) => angle === 90);
assert(lookIndex >= 0, "+x look direction is sampled");
assertNear(pattern.responseReal[lookIndex], -1 / 6, 1e-12, "signed real response");
assertNear(
pattern.responseImaginary[lookIndex],
-Math.sqrt(3) / 6,
1e-12,
"signed imaginary response",
);
});
test("display dB floor never changes raw array factor or physical metrics", () => {
const array = arrayFromPositions([[-0.08575, 0, 0], [0.08575, 0, 0]]);
const shared = {
array,
frequencyHz: 1_000,
speedOfSound: 343,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: 720,
};
const shallow = computeReceiveBeamPattern({ ...shared, dbFloor: -30 });
const deep = computeReceiveBeamPattern({ ...shared, dbFloor: -100 });
for (let index = 0; index < shallow.sampleCount; index += 1) {
assertNear(
shallow.responsePower[index],
deep.responsePower[index],
0,
"raw power is floor-independent at " + index,
);
}
assertNear(
shallow.metrics.halfPowerBeamwidth.widthDeg,
deep.metrics.halfPowerBeamwidth.widthDeg,
0,
"HPBW is floor-independent",
);
const nullIndex = [...shallow.anglesDeg].findIndex((angle) => angle === 90);
assertEqual(shallow.displayDb[nullIndex], -30, "shallow display floor");
assertEqual(deep.displayDb[nullIndex], -100, "deep display floor");
assert(
shallow.responseDb[nullIndex] < -300,
"raw null remains below both display floors",
);
});
test("receive array factor is invariant to translating every microphone", () => {
const basePositions = [[-0.12, 0.03, 0], [0.04, -0.08, 0.02], [0.15, 0.07, -0.01]];
const translation = [1_000, -2_000, 500];
const translatedPositions = basePositions.map((position) =>
position.map((coordinate, axis) => coordinate + translation[axis]));
const options = {
frequencyHz: 7_500,
speedOfSound: 343,
cut: "xy",
steeringAngleDeg: 23,
sampleCount: 720,
};
const base = computeReceiveBeamPattern({ ...options, array: arrayFromPositions(basePositions) });
const translated = computeReceiveBeamPattern({
...options,
array: arrayFromPositions(translatedPositions),
});
for (let index = 0; index < base.sampleCount; index += 1) {
assertNear(
translated.responseLinear[index],
base.responseLinear[index],
1e-11,
"translation-invariant sample " + index,
);
}
});
test("beam pattern uses analog frequency directly without Nyquist folding", () => {
const highFrequencyHz = 49_125;
const speedOfSound = 343;
const halfHighWavelength = speedOfSound / (2 * highFrequencyHz);
const array = arrayFromPositions([[0, 0, 0], [halfHighWavelength, 0, 0]]);
const highAnalog = computeReceiveBeamPattern({
array,
frequencyHz: highFrequencyHz,
speedOfSound,
cut: "xy",
steeringAngleDeg: 90,
sampleCount: 360,
});
const foldedTemporalAlias = computeReceiveBeamPattern({
array,
frequencyHz: 1_125,
speedOfSound,
cut: "xy",
steeringAngleDeg: 90,
sampleCount: 360,
});
assertEqual(highAnalog.frequencyHz, highFrequencyHz, "analog hypothesis is preserved");
assertNear(
highAnalog.wavelengthM,
speedOfSound / highFrequencyHz,
1e-15,
"analog wavelength",
);
assert(
Math.abs(sampleAtAngle(highAnalog, 0) - sampleAtAngle(foldedTemporalAlias, 0)) > 0.1,
"spatial pattern is not computed from the folded ADC alias",
);
});
test("coarse high-frequency cuts preserve raw samples but withhold unresolved metrics", () => {
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([[-0.5, 0, 0], [0.5, 0, 0]]),
frequencyHz: 100_000,
speedOfSound: 343,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: 360,
});
assert(!pattern.angularSampling.metricResolutionSatisfied, "phase-step audit fails");
assert(
pattern.angularSampling.maximumAdjacentPhaseStepRadBound >
pattern.angularSampling.metricPhaseStepLimitRad,
"result exposes the physical phase-step bound",
);
assertEqual(
pattern.metrics.halfPowerBeamwidth.status,
"resolution-unresolved",
"HPBW is withheld",
);
assertEqual(
pattern.metrics.sampledLocalMaxima.status,
"resolution-unresolved",
"peak interpretation is withheld",
);
assertEqual(pattern.responsePower.length, 360, "raw sampled power remains available");
});
test("non-constant cuts without sampled half-power crossings do not claim 360-degree HPBW", () => {
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([[-0.0005, 0, 0], [0.0005, 0, 0]]),
frequencyHz: 1_000,
speedOfSound: 343,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: 720,
});
assert(pattern.angularSampling.projectedApertureM > 0, "array is not constant on cut");
assert(
Math.min(...pattern.responsePower) > 0.5,
"sampled cut stays above half power",
);
assertEqual(
pattern.metrics.halfPowerBeamwidth.status,
"no-sampled-half-power-crossing",
"missing crossing remains unresolved",
);
assertEqual(pattern.metrics.halfPowerBeamwidth.widthDeg, null, "no fabricated width");
assertEqual(
pattern.metrics.halfPowerBeamwidth.fullCircleAboveHalfPower,
null,
"full-circle claim is withheld",
);
});
test("auto angular sampling increases resolution and reports when the safety cap is insufficient", () => {
const moderate = computeReceiveBeamPattern({
array: arrayFromPositions([[-0.225, 0, 0], [0.225, 0, 0]]),
frequencyHz: 49_125,
speedOfSound: 343,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: "auto",
});
assert(moderate.sampleCount > 720, "auto mode increases angular samples");
assert(moderate.angularSampling.metricResolutionSatisfied, "moderate case becomes resolved");
assert(!moderate.angularSampling.autoCapped, "moderate case fits the cap");
const extreme = computeReceiveBeamPattern({
array: arrayFromPositions([[-10, 0, 0], [10, 0, 0]]),
frequencyHz: 1_000_000,
speedOfSound: 343,
cut: "xz",
steeringAngleDeg: 0,
sampleCount: "auto",
});
assertEqual(extreme.sampleCount, 14_400, "auto mode obeys the angular cap");
assert(extreme.angularSampling.autoCapped, "cap is explicit");
assert(!extreme.angularSampling.metricResolutionSatisfied, "extreme metric remains unresolved");
});
test("beam-pattern preflight rejects invalid input and excessive work", () => {
const array = arrayFromPositions([[0, 0, 0], [0.1, 0, 0]]);
let frequencyError = null;
try {
computeReceiveBeamPattern({ array, frequencyHz: 0 });
} catch (error) {
frequencyError = error;
}
assert(frequencyError instanceof RangeError, "zero analog frequency is rejected");
let workError = null;
try {
computeReceiveBeamPattern({
array,
frequencyHz: 1_000,
sampleCount: 360,
maximumEvaluations: 911,
});
} catch (error) {
workError = error;
}
assert(workError instanceof RangeError, "work cap is checked before evaluation");
assert(workError.message.includes("912"), "error reports maximum evaluation count");
let microphoneLimitError = null;
try {
computeReceiveBeamPattern({
array: arrayFromPositions(
Array.from({ length: 1_025 }, (_, index) => [index / 1000, 0, 0]),
),
frequencyHz: 1_000,
});
} catch (error) {
microphoneLimitError = error;
}
assert(microphoneLimitError instanceof RangeError, "microphone cap precedes pairwise audit");
assert(
microphoneLimitError.message.includes("1024"),
"microphone cap is explicit",
);
let baselineError = null;
try {
computeReceiveBeamPattern({
array,
frequencyHz: 1_000,
maximumBaselineComparisons: 0,
});
} catch (error) {
baselineError = error;
}
assert(baselineError instanceof RangeError, "baseline pair cap is checked");
assert(baselineError.message.includes("1 projected-baseline"), "pair work is explicit");
let frequencyLimitError = null;
try {
computeReceiveBeamPattern({ array, frequencyHz: 1_000_001 });
} catch (error) {
frequencyLimitError = error;
}
assert(frequencyLimitError instanceof RangeError, "extreme analog frequency is bounded");
assert(frequencyLimitError.message.includes("1000000"), "frequency cap is explicit");
});
test("co-located pattern accepts an exact sample-only evaluation cap", () => {
const pattern = computeReceiveBeamPattern({
array: arrayFromPositions([[0, 0, 0]]),
frequencyHz: 1_000,
sampleCount: 360,
maximumEvaluations: 360,
});
assertEqual(pattern.evaluationCount, 360, "exact one-microphone sample work");
assertEqual(pattern.workload.maximumMetricEvaluationCount, 0, "constant cut reserves no HPBW work");
let error = null;
try {
computeReceiveBeamPattern({
array: arrayFromPositions([[0, 0, 0]]),
frequencyHz: 1_000,
sampleCount: 360,
maximumEvaluations: 359,
});
} catch (caught) {
error = caught;
}
assert(error instanceof RangeError, "strict cap rejects one fewer evaluation");
});