Revalidation process for IMS waveform technologies stations

S. Bazarragchaa1, P.Martysevich1, A. Kramer1, P. Campus1, A. Molero2, Y.Starovoyt2 1 CTBTO, International Monitoring System Division, EngineeringDevelopment section, Wagramerstrasse 5, 1220 Vienna, Austria;2 Addproject, C/Conde Duque 48, bajo izda, 28015 Madrid, Spain The revalidation process of International Monitoring System (IMS) stations of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a fundamental step of the IMS sustainment to demonstrate the compliance of such stations with the minimum requirements established at the time of their certification (IMS requirements). Revalidation should be undertaken if any change occurs at a station that significantly affects its system response, detection capability or data availability (configuration change). Upon completion of the configuration change (or recapitalization) works at the station, a revalidation report is submitted by the IMS Engineering and Development Section of the CTBTO for consideration and review by an appointed Certification Group. The report addresses, among several technical aspects, noise study analysis tailored for different equipment settings; station calibration; data format settings and population of relevant databases.