The Ocean Surface Topography Mission (OSTM)/Jason-2 is a follow-on altimetric mission to the very successful TOPEX/Poseidon mission and Jason-1. It is a joint mission between NASA and CNES (French space agency). It launched June 20, 2008 and began data collection on July 12, 2008. OSTM is capable of measuring significant wave height, sigma0, dry and wet troposphere and ionosphere, which can be used to calculate sea surface height and anomalies and total electron content.
OSTM has a repeat period of approximately 10 days with 254 passes per cycle. A list of cycle start times can be found here.
Sometimes there maybe anomalous or missing data. Occasionally OSTM must perform maneuvers to maintain orbit. This may cause anomalous values so a list of maneuvers is available here. When the satellite detects something abnormal it will go into safehold and will turn off all instruments and no data will be collected. A list of safeholds and periods of no data collection can be found here.