Citizen Weather Observer Program
The Citizen Weather Observer Program (hereinafter referred to as CWOP ) enables users of automatic weather stations to transmit their measured values wirelessly or via the Internet to the US “ Mesonet ”. This data is collected, processed and processed by institutions such as the National Oceanic and Atmospheric Administration (NOAA) and made freely accessible to everyone on the Internet.
history
The CWOP network was originally created when radio amateurs in the USA began using the packet radio network to exchange telemetry and weather data in the late 1980s . At the beginning of the 1990s, the APRS protocol developed into a quasi-standard, which made it easier to network the stations and process the data through the standardization of frequencies and data formats. Later, the connection of APRS and the Internet via the so-called APRS Internet Service (ARPS-IS) under the name APRSWXNET also enabled use by participants who do not have an amateur radio license .
Around 12,400 participants (as of October 2011) are now taking part in the CWOP worldwide. These are mostly radio amateurs and other private operators, but also municipal and public institutions such as B. Schools, universities, weather stations and airfields that provide their local weather data.
Data format
The format for the data transmitted in APRSWXNET is based on the APRS specification, whereby the values are available in directly readable form, but in the imperial system . A typical data record has the format
DW1234>APRS,TCPXX*,qAX,CWOP-1:@040822z4924.23N/00843.63E_211/011g014t033r000P000p000h99b10142.PCWS2.93.17E31
and includes:
| section | contained data |
|---|---|
| DW1234 | CWOP identification or amateur radio call sign of the weather station |
| APRS, TCPXX *, qAX, CWOP-1: @ | APRS-specific information on the data path (here: APRS via TCP / IP ) and representation |
| 040822z | Time stamp of the measurement (format: HHMMSS, based on Zulu time ) |
| 4924.23N / 00843.63E | Location of the weather station ( WGS-84 coordinates) |
| _211 / 011 | Wind direction in degrees and wind speed (in mph ) |
| g014 | Wind speed in gusts (in mph) |
| t033 | Air temperature in degrees Fahrenheit |
| r000 | Rainfall in the past hour (in 1 / 100 -inch ) |
| P000 | Rainfall since midnight (in 1 / 100 -inch) |
| p000 | Precipitation amount for the past 24 hours (in 1 / 100th of an inch) |
| h99 | relative humidity (in percent) |
| b10142 | Air pressure (in 1 / 10 hectopascals ) |
| .PCWS2.93.17E31 | Information on the technology and / or software used (here: "PC weather station v2.93") |
Timeliness and accuracy
The measured values are transmitted in real time by the individual stations, although the frequency of the measurement is not mandatory and depends on factors such as B. the minimization of energy consumption in autonomous stations depends. Added to this are delays caused by routing and transmission within the APRS network.
The accuracy of the data is subject to restrictions. On the one hand, and used originally developed for simple transmission via radio data format limits the resolution: temperatures can for example corresponding to only 1 ° F 5 / 9 ° C are transmitted exactly. Furthermore, there are inevitably deviations from the fact that a large number of the (mostly privately operated) stations do not follow a uniform standard with regard to the location of the sensors, their tolerances and calibration. As with all such open networks, the measured values are therefore more suitable for observing situations and trends than for obtaining absolute statements or require further data processing for quality assurance.
See also
Web links
- Homepage of the CWOP project (English)
- Real-time map display of APRS, AIS and CWOP data at aprs.fi
Individual evidence
- ↑ MADIS Meteorological Surface Integrated Mesonet Data Providers (English), accessed on January 21, 2012
- ↑ Specification of APRS-IS (English), accessed January 21, 2012
- ↑ current list of participants at WXQA.com
- ↑ APRS Protocol Reference - APRS Protocol , Version 1.0.1, PDF, English
- ↑ Example: "Guideline for Automatic Climate Stations in the German Weather Service" , viewed on January 21, 2012
- ↑ MADIS Meteorological Surface Quality Control ( Memento of the original from January 5, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English), accessed January 21, 2012
