5.3 Data Recovery

5.3.1 Length of Record

The duration of a meteorological monitoring program should be set to ensure that worst-case meteorological conditions are adequately represented in the data base; the minimum duration for most dispersion modeling applications is one year. Recommendations on the length of record for regulatory dispersion modeling as published in The Guideline on Air Quality Models [1] are: five years of National Weather Service (NWS) meteorological data or at least one year of site-specific data. Consecutive years from the most recent, readily available 5-year period are preferred.

5. SYSTEM PERFORMANCE
 5.1 System Accuracies
 5.2 Response Characteristics of Meteorological Sensors
  5.3 Data Recovery
      5.3.1 Length of Record
      5.3.2 Completeness Requirement
  5.4 Recommendations