The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the 1st generation Robotic Optical Transient Search Experiment (ROTSE-I) using a robotic system of four co-mounted unfiltered tele-photo lenses equipped with CCD cameras. 

The survey was conducted from Los Alamos, NM, and primarily covers the entire northern sky. Some data in southern fields between declinations 0 deg and -38 deg is also available, although with fewer epochs and noticeably lesser quality. 

NSVS contains light curves for approximately 14 million objects and typically 100 to 400 good quality measurements per object. 

Peranso makes use of NSVS data provided by SkyDot (Sky Database for Objects in Time-Domain) at Los Alamos National Laboratory.