Variablesweep

Variable sweep is a method used in measurement, signal processing, and related fields in which the progression through a parameter range is performed with a nonuniform sweep rate or path. A sweep may traverse quantities such as frequency, time, voltage, or other control variables. In a variable-sweep scheme, the step size, dwell time, or rate is modulated according to a predefined profile or adaptive rule, with the goal of prioritizing precision where it is most informative or where the signal is changing rapidly.

Common implementations include nonlinear frequency sweeps (for example, logarithmic or piecewise-linear sweeps) and time-varying sweep rates that slow down near regions of interest. In adaptive variants, the instrument adjusts sweep parameters on the fly based on measurements taken in earlier steps, potentially refining resolution after detecting features.

Advantages include more efficient use of measurement time, better resolution in critical regions, and potentially improved sensitivity or signal-to-noise within a selected subset of the sweep range. Drawbacks include added control complexity, the need for careful calibration, and challenges in interpreting data collected on nonuniform grids without appropriate resampling or weighting.

Variable-sweep techniques are used in spectrum analyzers, network analyzers, oscilloscopes, and other instruments that scan a range of a parameter. They also appear in scientific experiments and imaging where parameter sweeps must be conducted efficiently. Related concepts include logarithmic and exponential sweeps, chirp signals, and adaptive sampling.