Remote Stations

• A weatherproof omnidirectional microphone with a wind shield and protection against birds.
• The signal from the microphone is connected to a statistical noise analyser. The most modern stations include analysers which also make audio recordings and frequency analyses (1/1 and 1/3 octaves).
• The information stored in the analyser is transferred to the central station through a modem using a high-speed ISDN telephone line.

Transmission system

The central station has a distributor with ISDN adapters that communicate at regular intervals with the stations to download the data from each one.

If necessary, the information stored in a station with which automatic communication was not possible can be collected with a forced call or by connecting a laptop directly to it and then transferring the data to the central system.

Central station

The system's central station basically consists of a management computer and a server.

The so-called management computer makes the automatic calls and generates the raw database for treatment by the rest of the users. It can also call any station to show the noise levels in real time, second by second, occurring in that station.

The server maintains the databases with all the noise information from the management computer. The raw values (transferred but not processed) are analysed by the system administrator to determine anomalies that may arise. It carries out the automatic calculation of daily, monthly and even annual indicators prepared in the management computer.

The system prepares the daily reports that are sent to the Press and uploaded to the Web site www.mambiente.munimadrid.es where they are available to anyone who wishes to consult them.