Distributed sensor system with remote sensor nodes and centralized data processing

1. A distributed sensor system comprising:

a plurality of spatially distributed base units in communication with a data network, each base unit comprising a controller and one or more sensor modules, each sensor module comprising a sensor configured to measure an air quality parameter, the controller in each base unit being configured to transmit raw sensor data associated with each of the sensor modules over the data network, the raw sensor data for a sensor module being identified by a sensor identifier uniquely identifying a sensor in a sensor module in a base unit and a board identifier uniquely identifying the base unit in the system; and

a central server in communication with the data network, the central server comprising a data processor and one or more databases, the central server configured to receive raw sensor data from the plurality of base units and to store the raw sensor data in a database, wherein the central server comprises a calibration data database and a sensor data database, the sensor data database storing the raw sensor data where each entry of the raw sensor data is associated with a sensor identifier and a board identifier, the calibration data database storing calibration data for sensors in the sensor modules of the base units where each entry of calibration data is associated with a sensor identifier and a board identifier, and wherein the central server generates calibrated sensor data for a first sensor using the raw sensor data stored in the sensor data database associated with the first sensor and using the calibration data stored in the calibration data database associated with the first sensor, the raw sensor data and the calibration data associated with the first sensor being identified in the sensor data database and the calibration data database, respectively, by the same sensor identifier and the same board identifier.

2. The distributed sensor system of claim 1 , wherein each base unit in the plurality of base units is configured to communicate with the data network through wired communication or a wireless communication.

3. The distributed sensor system of claim 1 , wherein a first base unit and a second base unit in the plurality of base units comprise sensors of the same sensor type.

4. The distributed sensor system of claim 1 , wherein a first base unit and a second base unit in the plurality of base units comprise sensors of different sensor types.

5. The distributed sensor system of claim 1 , wherein each of the one or more sensor modules in the plurality of base units is equipped with a universal connector and each sensor module is removably attached to a matching receptacle formed in the base unit.

6. The distributed sensor system of claim 5 , wherein each base unit comprises a printed circuit board having the controller and a plurality of matching receptacles formed thereon, the board identifier identifying the printed circuit board in a base unit.

7. The distributed sensor system of claim 1 , wherein the controller comprises a transceiver supporting wired or wireless communication.

8. The distributed sensor system of claim 1 , wherein the central server updates the calibration data for a sensor in the calibration data database, the central server regenerating the calibrated sensor data using the raw sensor data stored in the sensor data database and the updated calibration data having the same sensor identifier and board identifier as the raw sensor data.

9. The distributed sensor system of claim 1 , wherein the controller further comprises a memory storing calibration data for at least one sensor module in the base unit, the controller further configured to perform a calibration of the raw sensor data at the base unit using the stored calibration data.

10. A method of performing calibration in a distributed sensor system comprising a plurality of spatially distributed base units in communication with a central server over a data network, each base unit comprising one or more sensors configured to measure an air quality parameter, the method comprising:

maintaining on the central server calibration data for sensors in the distributed sensor system in a calibration data database, the calibration data for a sensor being associated with a sensor identifier uniquely identifying the sensor in a base unit and a board identifier uniquely identifying the base unit in the system;

receiving at the central server raw sensor data from a first sensor in a first base unit;

identifying at the central server the raw sensor data by a first sensor identifier identifying the first sensor and a first board identifier identifying the first base unit;

retrieving from the calibration data database the calibration data for the first sensor using the first sensor identifier and the first board identifier;

adjusting the raw sensor data using the retrieved calibration data; and

generating at the central server calibrated sensor data for the first sensor.

11. The method of claim 10 , further comprising:

storing on the central server the raw sensor data for the first sensor in a sensor data database;

updating at the central server the calibration data for the first sensor identified by the first sensor identifier and the first board identifier;

retrieving the raw sensor data for the first sensor from the sensor data database using the first sensor identifier and the first board identifier;

adjusting the raw sensor data using the updated calibration data; and

generating at the central server updated calibrated sensor data for the first sensor.

12. The method of claim 10 , wherein the calibration data comprises a gain correction value, or an offset correction value, or a slope correction value, or a non-linear scaling value.

13. The method of claim 10 , wherein maintaining on the central server calibration data for sensors in the distributed sensor system in a calibration data database comprises:

associating calibration data for each sensor with a valid date range.

14. The method of claim 10 , wherein maintaining on the central server calibration data for sensors in the distributed sensor system in a calibration data database comprises:

associating calibration data for each sensor with a valid indicator.