The NAEMS is collecting continuous air emission data from 38 barns at five dairies, five pork production sites, three egg layer operations, one layer manure shed, and one broiler facility for a period of 2 years. At each barn monitoring site, an on-farm instrumentation shelter houses equipment for measuring pollutant concentrations, barn airflows, operational processes, and environmental variables. A multipoint gas sampling system delivers selected air streams to gas analyzers. PM concentrations are monitored at one representative exhaust location per barn. Concentrations of NH3, H2S, VOC, and PM (PM10, PM2.5, and TSP), building ventilation rate, and supporting parameters are monitored online at all sites. Motion sensors monitor animal, worker and vehicle activity. Barn ventilation rate is assessed by monitoring fans and barn static pressure in MV barns, and air velocities through ventilation openings in naturally-ventilated buildings. Data is logged every 15 and 60 s. Custom software (CAPECAB) efficiently handles large amounts of data being generated by NAEMS, and is used to validate, and process the data.