Citizen Weather Observer Program

The Citizens Weather Observer Program (CWOP) is a program to collect weather observations from thousands of privately operated weather stations, into the FindUdatabase, and forard it to the Meteorological Assimilation Data Ingest System (MADIS), operated by the National Oceanic and Atmospheric Administration (NOAA).

It was originally set up by Amateur_radio amateur radio operators experimenting with Packet_radio packet radio, but now includes a majority of Internet-only connected stations. As of 2007, well over 4,000 stations worldwide report regularly.

The FindU database is a set of privately operated Internet servers, run by Steve Dimse, (amateur radio callsign k4hg). Numerous IGates (Internet Gateways) receive broadcast amateur radio Automatic_Position_Reporting_System APRS packets containing position and short messages (including telemetry such weather observations), and route the data to the FindU servers. Weather observations may be polled directly from FindU, and the data is forwarded to MADIS for ingest. APRS messages may also originate directly from computers on the Internet without being broadcast on the radio waves.

The MADIS system integrates weather observations from numerous different sources, including CWOP via FindU, and drives a number of different weather forecasting products. Incoming data are subjected to temporary and spatial consistency checks, and quality flags are stored with the data, to enable users to access the most trustworthy data possible.

The amateur radio connection makes it inexpensive and simple for an individual to install consumer-level weather sensors at a point of interest, connect them to a radio transmitter via a simple APRS modem, and start sharing weather reports with forecasters worldwide. Solar power and radio transmission makes it possible to drop completely self-contained weather sensors on unattended and un-wired sites, allowing for a dense MESONET of data to be collected.