Timing Capabilities

In the SPI standard operation mode, each photon data set includes timing information given by a 100 s clock signal. This clock is synchronized to the on board clock, and thus to the UTC. The timing error for SPI is derived from

• the accuracy of the on-board clock and the synchronization,
• the conversion between on-board time and UTC,
• the conversion between UTC arrival time at the spacecraft and the arrival time at the solar system barycentre when appropriate.

The resulting SPI timing accuracy calculated in this way is 129 s, at a 3 level, and a 90% confidence accuracy of 94 s.