Ningaloo (Milyering) Automatic Weather Station

The weather station is an AIMS Mk3 System

Data recorded: Barometric Pressure, Air Temperature, Solar Radiation (PAR), Wind Direction True (vector averaged), Wind Speed True (30 min average).

1. Operation and Weather Sensors

The weather stations collect and store data in electronic memory every half-hour. A central base station calls each remote station regularly using HF radio or telephone lines. The data is transmitted over the radio as a frequency shift keyed signal, organised as packets of information. Errors are detected using parity and check sum methods. Invalid packets are identified by the Base Station, which requests they be sent again. This concept allows recovery of a very high percentage of the data despite poor communications. Remote stations store data for 21 days. Features such as automatic operation, remote control, remote time setting, built in diagnostics, have been developed and incorporated.

Data from AIMS weather stations are subjected to two quality control processes.

The first quality control process involves applying automatic rules to the raw data to flag data points that are unlikely to be correct. These rules flag:

- Values frequently associated with sensors which are faulty, in need of a service or are not working properly.
- Values outside believable ranges.
- Values that are out of range compared to other nearby stations.

The second quality control process involves manual visualisation of all data. Data from all sensors are individually graphed and compared to sensors on the same station (e.g. water temperature 1 and water temperature 2), calibrated temperature loggers, predicted values (e.g. PAR) or compared to sensors from nearby stations (including Bureau of Meteorology stations in the case of barometric pressure, wind speed and direction).

After these processes have been applied the data can be categorised in the following three levels.

Level 0: Raw unprocessed data as received from the AWS. This data has had no quality control process applied to it.

Level 1: Level 1 data has had all suspect data points removed but no suspect data points are corrected.

Level 2: Level 2 data has had all suspect data points that were removed in Level 1 corrected where possible.

Data from all three levels can be accessed from the AIMS weather station web site.