The Pain and the Gain of Rescuing Historic Science Data: The Nimbus Data Rescue Project

Abstract:

While technology of our satellite systems have greatly improved the quality of observations over the past 50 years, it is the legacy of the first global coverage environment satellites, the Nimbus systems launched by NASA in the mid-1960s, that marks the beginning of a unique perspective from space. Such early data can extend our climate record and provide important context in longer-term climate changes.

Unfortunately, the Nimbus data nearly disappeared before its value was recognized and attempts to recover the data were undertaken. While the Nimbus data was never truly lost, it was in a form that could not be read and was not organized in a way that could be accessed with modern computer systems. The rescue and recovery of the Nimbus data began in 2007 with an initiative by the NASA Goddard Space Flight Center. Without the Goddard efforts, the early Nimbus data might be forever dark. The Nimbus Rescue Project has just completed processing and archival of the Nimbus 4 visible and infrared observations from 1970 and 1971. This adds to our rescue efforts from Nimbus 1, 2 and 3 for 1964, 1966 and 1969. The procedures to recover the Nimbus data, from both film and tape, could be used by other data rescue projects, however the algorithms presented will tend to be Nimbus specific. The compositing of the mapped minimum brightness over weekly intervals resulted in never before seen views of the Polar Regions, such as a visible light view of the Antarctic ice extent from October 1970 (Figure 1).

The Nimbus data recovery and reprocessing into modern formats was important, however it was the utility of the data as a part of the satellite climate record that made it valuable. Data rescue projects are often both difficult and time consuming but the data they bring back to the science community makes these efforts worthwhile.