Instruments

The Alaska Geophysics Arctic Observing Network is unusual among observing networks because of its large geographic extent, grid-like spacing, and the assemblage of sensor types that combines atmospheric with solid earth capabilities. By co-locating such a variety of instruments, this network naturally lends itself to enhancing cross-disciplinary research. All these change-based research questions require consistent and continuous long-term data—precisely what the Alaska Geophysics Arctic Observing Network is poised to provide.

Design of a typical USArray station in northern and western Alaska. Batteries, power controllers, datalogger, modems, etc. are housed inside the hut. Co-located instruments include:

  • Vaisala W XT520 weather station, installed roughly 2 meters above ground, capturing wind speed and direction, precipitation, barometric pressure, temperature, and relative humidity

  • A 3-component broadband seismometer installed at a depth of two to three meters (Nanometrics T120PH or Kinemetrics STS-4B/5A)

  • MEMS state-of-health barometer

  • NCPA infrasound sensor

  • SETRA microbarograph

  • Soil temperature profiler with thermistors at depths of 0.1, 0.2, 0.3, 0.5, 0.75, 1, and 3 m



All data streams are managed through a Quanterra Q330 data logger and are telemetered at sample rates between 0.1 and 50HZ depending on the channel, except for a soil temperature, which is retrieved on-site. Communication at most sites is accomplished through an Inmarsat BGAN satellite uplink. At a handful of sites data is communicated over a VSAT satellite uplink, a cellular carrier, or through a third-party partnership. An independent low-volume Iridium communications package streams state of health data and provides a networking backdoor that can be used to remotely troubleshoot issues even when the primary communications link is down. The sensors and communication links require autonomous 24/7 power. This is achieved through banks of lithium batteries that have a typical combined storage capacity of 19-24 KWHr. Solar panels provide recharge capabilities that vary considerably with the time of year.