NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and has resumed surveying the sky at 3.4 and 4.6 μm. The scientific objectives of the NEOWISE reactivation mission are to detect, track, and characterize near-Earth asteroids and comets. The search for minor planets resumed on 2013 December 23, and the first new near-Earth object (NEO) was discovered 6 days later. As an infrared survey, NEOWISE detects asteroids based on their thermal emission and is equally sensitive to high and low albedo objects; consequently, NEOWISE-discovered NEOs tend to be large and dark. Over the course of its three-year mission, NEOWISE will determine radiometrically derived diameters and albedos for ∼2000 NEOs and tens of thousands of Main Belt asteroids. The 32 months of hibernation have had no significant effect on the mission's performance. Image quality, sensitivity, photometric and astrometric accuracy, completeness, and the rate of minor planet detections are all essentially unchanged from the prime mission's post-cryogenic phase.

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Lock-in amplifiers are widely used in metrology to extract a sinusoidal component of a known frequency from a signal that is noisy, returning estimates of the amplitude and phase of the component. A number of questions arise regarding the use by metrologists of the results returned by a lock-in amplifier. For example, what uncertainties should be associated with the estimates returned? How do these uncertainties vary as the signal-to-noise ratio changes? How do instrument errors affect the estimates and the associated uncertainties? In this paper a software simulation tool is described that may be used to process simulated or real (measured) signals, with the user allowed to associate uncertainties with the values of parameters that define the simulated signal and with those that define the operation of the instrument. The results of applying the software simulation tool to both simulated signals and real signals from infrared radiation and nanoindentation experiments are described.