non-uniform sampling 

Initialism: NUS
https://doi.org/10.1351/goldbook.08381
Technique employed within a high dimensionality nuclear magnetic resonance spectroscopy experiment that acquires only a subset of the data points traditionally acquired linearly thus enabling a reduction in experiment time or an increased resolution in the resultant spectra.
Note:
NUS uses reconstruction methods to allow the extraction of complete sets of chemical shift information.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 697 [Terms] [Paper]