The Local Station

The local station is situated at Neenton in South Shropshire. From the distant stations the seismic telemetry is beamed in by VHF radio in real-time, 24hours per day, 7 days per week, 365 days per year.

The Spaceguard site is 38Km with Brown Clee at 4Km and Bryn Du 68Km. The seismic telemetry is received via the VHF radio's and the audio signals are then fed via cat5 network cable to a 4 channel real-time FM seismic demodulator . Here the tone is converted into a voltage and is then an amplified replica of the remote stations seismic signal. This voltage is passed on to digitiser and further to a PC. 'Earthworm' software processes the real-time activity for the remote stations and should an event occur the predetermined trigger levels start recording the data to the hard drive.The seismic files are then analysed using 'Winquake' software. The Earthworm module "Heli" creates heliplot images which are uploaded to the internet every 20 mins.

Its now December 2009 and I have just completed the refurbishment of a Willmore triaxial borehole seismometer. This instrument has now been installed in the new seismic vault, prepared when the weather was more suited to such a task.

Above, is the block diagram of the entire local station whilst below is a photo of the "Seislogger" setup in my workshop.The setup is also connected to a weather station and APRS amateur radio. The APRS is used a means of transmitting weather data via the VHF amateur radio network. The weather data is also available to view on the internet.

 

 

 

Here to the right is the new seismic vault . It is 1.5 metres in depth and 0.4 metres diameter. The refurbished Willmore triaxial borehole seismometer pictured below will be installed into this vault. The Willmore Triaxial borehole seismometer manufactured by Sensonics. This instrument was donated by the British Geological Survey several years ago. During its refurbishment its period was adjustet to ~3 sec. This instrument is Triaxial, in that it is 3 sensors in one, vertical is uppermost, then North/South and East/West dependant on installation. Pictured above is a screenshot of Seislog.