Notation Registry¶

This page is the canonical registry for mathematical quantities used in the analyzer docs and code.

Use it together with Code-Symbol Mapping and Terminology and Status Labels.

Conventions¶

Code identifiers are written in snake_case.
Units are explicit when a quantity is meaningful.
dBFS means decibels relative to full-scale complex samples.
Heuristic quantities are documented as heuristics, not calibrated measurements.

Capture Geometry¶

Symbol	English name	Unit	Meaning	Canonical code identifier	Implementation path	Test path
`f_c`	center frequency	Hz	RF center frequency for the current source and spectrum frame	`SourceConfig.center_frequency_hz`, `SpectrumFrame.center_frequency_hz`, `Marker.center_frequency_hz`, `DetectionResult.center_frequency_hz`	`include/sdr_analyzer/config.hpp`, `include/sdr_analyzer/results.hpp`, `src/core/session.cpp`, `src/dsp/analyzer.cpp`	`tests/test_session.cpp`, `tests/test_pipeline.cpp`, `tests/test_export_helper.py`
`f_s`	sample rate	Hz	Complex sample rate of the capture stream	`SourceConfig.sample_rate_hz`	`include/sdr_analyzer/config.hpp`, `src/core/session.cpp`, `src/sdr/simulator_source.cpp`, `src/sdr/rtltcp_source.cpp`, `src/sdr/uhd_source.cpp`, `src/sdr/soapy_source.cpp`	`tests/test_session.cpp`, `tests/test_record_replay.cpp`, `tests/test_export_helper.py`
`N_fft`	FFT size	samples	Number of complex samples transformed per analysis frame	`ProcessingConfig.fft_size`	`include/sdr_analyzer/config.hpp`, `src/dsp/analyzer.cpp`, `src/cli/main.cpp`, `python/sdr_signal_analyzer/gui.py`	`tests/test_pipeline.cpp`, `tests/test_session.cpp`, `tests/test_gui_validation.py`

Spectral Quantities¶

Symbol	English name	Unit	Meaning	Canonical code identifier	Implementation path	Test path
`Δf`	bin resolution	Hz/bin	Frequency spacing between adjacent FFT bins	`SpectrumFrame.bin_resolution_hz`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_export_helper.py`
`P_k`	bin power	dBFS/bin	Power at FFT bin `k` after windowing, FFT, and normalization	`SpectrumFrame.power_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`
`\bar{P}_k`	averaged bin power	dBFS/bin	Exponentially smoothed display power	`SpectrumFrame.average_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`
`H_k`	peak-hold bin power	dBFS/bin	Maximum retained per bin when peak hold is enabled	`SpectrumFrame.peak_hold_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`

Analysis Quantities¶

Symbol	English name	Unit	Meaning	Canonical code identifier	Implementation path	Test path
`P_floor`	noise floor	dBFS	Low-quantile estimate of the current frame noise floor	`AnalysisReport.noise_floor_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`
`P_peak`	strongest peak	dBFS	Maximum power found in the current frame	`AnalysisReport.strongest_peak_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`
`S_burst`	burst score	unitless	Ratio-based burst heuristic used only for coarse labeling	`AnalysisReport.burst_score`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`
`T_det`	detection threshold offset	dB	Prominence threshold above the estimated floor for peak candidates	`ProcessingConfig.detection_threshold_db`	`include/sdr_analyzer/config.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`
`T_bw`	bandwidth threshold offset	dB	Lower bound used with the roll-off rule to estimate occupied bandwidth	`ProcessingConfig.bandwidth_threshold_db`	`include/sdr_analyzer/config.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`

Marker And Detection Quantities¶

Symbol	English name	Unit	Meaning	Canonical code identifier	Implementation path	Test path
`f_m`	marker center frequency	Hz	Center frequency of a user-defined marker region	`Marker.center_frequency_hz`, `MarkerMeasurement.center_frequency_hz`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_export_helper.py`
`B_m`	marker bandwidth	Hz	Width of a user-defined marker region	`Marker.bandwidth_hz`, `MarkerMeasurement.bandwidth_hz`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_export_helper.py`
`f_det`	detection center frequency	Hz	Estimated signal center frequency for one detection	`DetectionResult.center_frequency_hz`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `src/cli/main.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`, `tests/test_cli_export.py`
`B_det`	detection bandwidth	Hz	Estimated occupied bandwidth for one detection	`DetectionResult.bandwidth_hz`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`, `tests/test_export_helper.py`
`P_det`	detection peak power	dBFS	Peak power at the detected bin	`DetectionResult.peak_power_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`
`L_det`	detection labels	unitless	Descriptive heuristic labels applied to a detection	`DetectionResult.labels`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `src/cli/main.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_record_replay.cpp`, `tests/test_cli_export.py`

Export And Session Surfaces¶

Symbol	English name	Unit	Meaning	Canonical code identifier	Implementation path	Test path
`n`	frame sequence	count	Monotonic snapshot counter within a session	`AnalyzerSnapshot.sequence`	`include/sdr_analyzer/results.hpp`, `src/core/session.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_session.cpp`, `tests/test_cli_export.py`
`P_marker,peak`	marker peak power	dBFS	Peak power within a marker region in one frame	`MarkerMeasurement.peak_power_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_export_helper.py`
`P_marker,avg`	marker average power	dBFS	Mean power within a marker region in one frame	`MarkerMeasurement.average_power_dbfs`	`include/sdr_analyzer/results.hpp`, `src/dsp/analyzer.cpp`, `python/sdr_signal_analyzer/export.py`	`tests/test_pipeline.cpp`, `tests/test_export_helper.py`

Reading Rule¶

If a prose statement refers to one of these quantities, use the same symbol, code identifier, and unit consistently in related docs and tests.

For any new quantity, add it here first, then update the code-symbol mapping page and any method pages that depend on it.