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Special Polar Equipment

DASes for Summer Only Polar Programs

Refraction Technology RT-130

The Reftek RT-130 is a 24bit, low power, robust and very portable seismic data recorder.  It is well suited for deployment in harsh climate environment and is easy to program and retrieve data in the field.  It can have 3 or 6 channels and records data on Compact Flash (CF) cards.

Year Round Equipment for Polar Projects

Here are several documents regarding year round equipment for Polar Projects. Batteries DAS Power Box Sensors Solar Station Enclosure Vaults

Summer Only Enclosure for Polar Projects

Here are several documents regarding summer-only equipment for Polar Projects. Batteries DAS Power Sensors Solar Station Enclosure Vaults

Specialized Polar Equipment

The Polar Program of IRIS/PASSCAL is dedicated to supporting with seismological research in the Arctic and Antarctic.  As opposed to traditional seismic stations installations around the world, instrumenting the Arctic or Antarctic require special consideration due to the extreme nature of the climatic conditions, temperature being the primary challenge.

Solar for Summer Only Enclosure

Summer Only Solar Panels

10W or 20W of solar power are usually sufficient for summer only experiment depending on a typical seismic station load.

IRIS PASSCAL's Polar Group uses both the Suntech STP010 (10W) and the STP020 (20W).  They are both efficient, monocrystalline silicon solar panels and have strong frames.  A mount was designed in house and manufactured specifically for these panels to attached them directly to our  “summer only” enclosures.

Station Enclosure for Summer Only

For summer only deployments, special and costly, heavy insulation is not needed since the temperature at that time of the year remains high enough that the electronic equipment and batteries will continue to operate normally without a heat source.

The PASSCAL Polar Group's summer only enclosures are made of molded,  heavy-duty, lightweight polyethylene on the outside and have closed cell foam liner inside, cut to accommodate the equipment and batteries.  They were designed with portability in mind and their outside dimensions are 24 in x 21 in x 11 in.

To ease deployment, the case was designed to contain all the equipment necessary as long as the sensor is an L28 or smaller.  At the site, only the seismometer needs to be installed and the solar panel needs to be mounted on top of the case.

Solar Equipment for Year Round Polar Programs

Low Power Solar Panel System

This solar panel system uses three Suntech STP020S  (20W) Monocrystalline Silicon solar panels mounted in a triangle to take advantage of the 24 hours a day solar insolation.   With the combination of cold temperature and solar reflection off the snow, this system produces close to 40W worth of solar power all day long in clear conditions.  This is more than adequate for most seismic recorder configurations.

This solar panel system is also very simple and quick to install in snow.  All that is needed is to have the base of the solar system buried in two feet or more of well compacted snow.  No guying is necessary.  Only one solar cable is needed to connect to a junction box located on the post.

Power Box Equipment for Summer Only Enclosure

Solar Charge Controllers

The Solar Charge Controller is responsible to properly charge the batteries when solar energy is available.  The GenaSun GV-4 controller, which is used for summer only experiments,  is a very efficient charge controller that uses the MPPT (Maximum Power Point Tracking) to maximize the power available at the solar panel, increasing the efficiency by 10 to 30% over traditional solar regulators.  It also uses very little power in low or no light conditions.

Nanometrics Trillium 240 Polar Sensor

Nanometrics Trillium 240

The Nanometrics Trillium 240 is a symmetric triaxial broadband instrument that has a flat response to ground velocity between 240s and 200Hz, and has a low self-noise, below the New Low Noise Model between 100s and 10Hz.  The manufacturer specifications of operating temperatures are between -20C and +50C, but the Trillium 240 has operated reliably for us to temperatures below -60C.  The power consumption at low seismic noise conditions and with the instrument well leveled is about 650mW.  The Trillium has a +/-1deg tilt tolerance, is fairly sensitive to varying temperature, but was designed to be insensitive to atmospheric variations.

The Trillium 240 is well suited for medium to long term experiments in the Arctic and Antarctic supported by the IRIS PASSCAL Polar Program.

Batteries for Summer Only Enclosure

Rechargeable Batteries

Rechargeable batteries are used for summer-only and year-round polar seismic experiments. For summer-only experiments, due to the roughly continuous sunlight, stations can be powered solely with rechargeable batteries.

For PASSCAL Polar experiments the preferred rechargeable battery is an AGM (Absorbent Glass Mat) battery manufactured by Concorde Battery Corporation. Both the Sun Xtender PVX-420T and PVX-560T work well for a summer deployment where only a limited amount of storage is required for cloudy days.

Primary Batteries

Primary batteries are usually not necessary for summer only deployment due to the ample amount of sunlight available.

 

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