[AUD-020][High] Pass sample period to the PSD simulator

[gabrielsantosphilips]

Audit finding

• ID: AUD-020
• Status: Verified defect
• Severity: High
• Confidence: High
• Audited revision: 2f479320d805a1f9f35ebe4afaaeeded48913a94

Problem

The PSD simulator passes total record duration inputSize / sampleRateHz as the PSD sampling interval. The numerical API expects one-sample period 1 / sampleRateHz.

Source:

numerical-toolbox-cpp/simulator/analysis/PowerDensitySpectrum/application/PsdSimulator.cpp

Lines 14 to 27 in 2f47932

	{
	template<std::size_t SegmentSize, std::size_t Overlap>
	PsdResult ComputeForSizeAndOverlap(float sampleRateHz, std::size_t inputSize,
	const std::vector<float>& signal, windowing::Window<float>& window)
	{
	using FFT = ::analysis::FastFourierTransformRadix2Impl<float, SegmentSize>;
	using TwiddleFactors = utils::TwiddleFactorsTable<float, SegmentSize / 2>;
	float samplingTime = static_cast<float>(inputSize) / sampleRateHz;
	float frequencyResolution = sampleRateHz / static_cast<float>(SegmentSize);
	::analysis::PowerSpectralDensity<float, SegmentSize, FFT, TwiddleFactors, Overlap> psd(window, samplingTime);
	infra::BoundedVector<float>::WithMaxSize<4096> input;

The default 1,024-sample record inflates power density by 1,024, approximately 30.10 dB.

Acceptance criteria

• Pass 1 / sampleRateHz to PowerSpectralDensity.
• Verify frequency bins and integrated density against an independent signal-variance reference.
• Test all supported segment sizes, overlaps, and windows using the real FFT path.