16. A system comprising, by one or more computer systems: means for accessing a set of sensor data that comprises: a plurality of sensor data aggregated together from a plurality of sensors in the sensor network; one or more time stamps for the sensor data; and metadata for the sensor data identifying one or more pre-determined attributes of the sensor data; means, including a processor, for generating an index of the set of sensor data according to a multi-dimensional array configured for querying of the set of sensor data along with a plurality of other sets of sensor data, one or more first ones of the dimensions of the multi-dimensional array comprising time and one or more second ones of the dimensions of the multi-dimensional array comprising one or more of the pre-determined sensor-data attributes; means for classifying the sensor data; means for, based on the classification, generating keywords for the sensor data using the metadata; means for forming a keyword frequency distribution by combining the keywords for different time windows; means for summarizing the sensor data by eigenvalues of an array associated with the sensor data in a keyword space and generating, using the eigenvalues, a set of searchable sensor data that represents the sensor data and has a smaller size than the sensor data; means for communicating the index of the set of sensor data in response to one or more queries of the set of sensor data along with a plurality of other sets of sensor data, and wherein generating the index comprises inputting the sensor data to a state machine with programmable rule criteria that is configured to drop sensor data that fail to meet the rule criteria as programmed.
18. The system of claim 16 , wherein the metadata comprises one or more identifiers designating one or more data types of the sensor data.