Specifications
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ISFF is designed to study
exchange processes between the atmosphere and Earth's surface.
This includes the direct measurement of fluxes of momentum, sensible and
latent heat, trace gases, and radiation as well as standard atmospheric
and surface variables.
With multiple sensors and data systems, measurements of horizontal and
vertical gradients also can be made.
This facility is flexible
and has been used in Arctic to desert conditions with sensor spacings from
1 m to 60 km (and separations of 1000s of km are possible).
Average statistics of all variables, including the second-order moments needed to compute fluxes, are a standard product of ISFF and are available in real-time for display. When possible, every data sample is archived to allow processing using spectral, wavelet, or conditional sampling methods. ISFF also supports the addition of user-supplied sensors with digital or analog outputs at data rates up to 10,000 samples/s.
Standard ISFF Sensors
Standard ISFF sensors are available for the following measurements:
momentum, sensible heat, and water vapor fluxes by eddy-correlation;
vertical profiles of wind, temperature, and humidity; radiation
fluxes; and soil temperature, soil moisture, and soil heat fluxes. The
ISFF sensors are a mix of commercial instruments and in-house
developments. Whenever possible, each sensor has a microprocessor that
provides sensor output in calibrated engineering units through a
serial communications link.
User-supplied or non-standard sensors can be readily accommodated by ISFF. Power and mounting are provided and the various data streams are easily integrated into the system.
Below is a listing of the most common ISFF sensors. Click the link in the "Model" column for documentation on that sensor.
| Sensor | Manufacturer | Model | Parameter | Rate | # |
| 3-D sonic anemometer | CSI | CSAT3 | u,v,w - m/s; Tvs - deg C | 60sps | 21 |
| UV absorption hygrometer | CSI | KH20 | vapor density - gm/m3 | 20Hz | 12 |
| H2O/CO2 Open-path Gas Analyzer | LI-COR | LI-7500 | H2O/CO2 concentration | 20sps | 1 |
| Prop-vane anemometer | NCAR/SSSF - R.M. Young | U, V - m/s | 5Hz | 7? | |
| Prop-vane anemometer | R.M. Young | 9101 | U, V - m/s | 5Hz | ~10 |
| Hygrothermometer | NCAR/SSSF - Vaisala | 50Y Humitter | T - deg C; RH -% | 1Hz | 14? |
| Pressure sensor | Vaisala | PTB220B | Pressure - mb | 1Hz | 9? |
| Net Radiometer | Micromet Systems | Q*7 | Net radiation - W/m2 | 1Hz | 9+? |
| Pyranometer | Kipp & Zonen | CM 21 | Global shortwave radiation - W/m2 | 1Hz | 8 |
| Pyranometer | Eppley | PSP | Global shortwave radiation - W/m2 | 1Hz | 25? |
| Pyrgeometer | Kipp & Zonen | CG4 | Global longwave radiation - W/m2 | 1Hz | 4 |
| Pyrgeometer | Eppley | PIR | Global longwave radiation - W/m2 | 1Hz | 10 |
| Soil temperature sensor | Micromet Systems (REBS) | Soil temperature - deg C | 1Hz | >10 | |
| Heat flux plate | Micromet Systems (REBS) | HFT-3 | Soil heat flux - W/m2 | 1Hz | >10 |
| Soil moisture | Decagon | Ech2o | Soil moisture - % vol | 1Hz | 10 |
| Soil thermal properties | Hukseflux | TP01 | conductivity, diffusivity, heat capacity | 1Hz | 9 |
| Surface temperature sensor | Everest Interscience | 4000.4ZL | Surface temp. - deg C | 1Hz | 10 |