US 7,333,725 B1 · Method and apparatus for metadata synchronization

Abstract

A method and apparatus provides for accurately synchronizing a plurality of sensors, as well as for providing accurate timing information (e.g. timing metadata) associated with the synchronized data capture. According to one aspect of the invention, an apparatus includes a synchronization circuit that stores a counter having a value corresponding to the delay characteristics of an associated sensor. The counter is used to provide a synchronization pulse to the associated sensor which is offset from a desired synchronization time by an amount that will compensate for the delay characteristics. In one example, one counter is provided for each associated sensor, allowing a high degree of accuracy in synchronization among a plurality of sensors. According to another aspect of the invention, the synchronization pulses are locked onto and derived from a pulse received from a GPS receiver. The GPS receiver is also used to mark time associated with the generated synchronization pulses, and thus obtain highly accurate time information (e.g. metadata) associated with the synchronization pulses provided to the sensors.

Claims32

Dependent claims

A timing apparatus comprising:

a first synchronization counter that receives a system clock and a pre-trigger, the first synchronization counter generating a first synchronization signal that is offset from the pre-trigger based on a first count of the system clock and a first delay characteristic, the first synchronization signal triggering a first data capture time;
and
a second synchronization counter that receives the system clock and the pre-trigger, the second synchronization counter generating a second synchronization signal different from the first synchronization signal and that is offset from the pre-trigger based on a second count of the system clock and a second delay characteristic, the second synchronization signal triggering a second data capture time,
wherein the respective offsets of the first and second synchronization signals from the common pre-trigger compensate for the respective first and second delay characteristics and cause the first and second data capture times to occur at substantially the same absolute time.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for metadata synchronization

Life of this patent

Method and apparatus for metadata synchronization

Life of this patent

Abstract

Claims32