Observing systems simulation experiment
From AMS Glossary
observing systems simulation experiment
(Abbreviated OSSE.) An experiment in which a model is assumed to represent the exact behavior of the physical system (the atmosphere) of interest.
The model results are then sampled in a fashion to mimic some real or hypothetical observing system. OSSEs are an inexpensive way to guide the design of new or enhanced observing systems or to evaluate the usefulness of existing observations.