ISFS Sensor List
  • Standard ISFS sensors are available for the following measurements:
    • 2D and 3D winds
    • Water vapor and carbon dioxide fluxes by eddy-correlation
    • Pressure, temperature, and relative humidity
    • Radiation fluxes
    • Momentum
    • Soil temperature, soil moisture, and soil heat fluxes
  • The ISFS 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 ISFS. Power and mounting are provided and the various data streams are easily integrated into the system.

Current ISFS sensors

Sensor Brand Parameter Rate Quantity
3-D sonic anemometer Campbell Scientific CSAT3 u, v, w - m/s; Tv - deg C 30 sps 21
3-D sonic anemometer Campbell Scientific CSAT3A u, v, w - m/s; Tv - deg C 60 sps 30
3-D sonic anemometer Campbell Scientific CSAT3B u, v, w - m/s; Tv - deg C 10, 20, 50 or 100 sps 7
3-D sonic anemometer Campbell Scientific CSAT3BH u, v, w - m/s; Tv - deg C 10, 20, 50 or 100 sps 1
H2O/CO2 Open-path Gas Analyzer Campbell Scientific EC150 H2O/CO2 density - g/m3 60 sps 30
2-D sonic anemometer Gill Instruments Wind Observer U, V - m/s 10 sps 30
Temperature/Relative Humidity NCAR SHT85 in aspirated shield T - deg C; RH - % 1 sps 90
Nanobarometer Paroscientific 6000 Pressure - mb 19.8 sps 30
Integrated Net Radiometer Hukseflux NR01 Global short/longwave in/out - W/m2 0.2 sps 30
Pyranometer  K&Z CM 21 Global shortwave radiation - W/m2 0.2 sps 8
Pyranometer Eppley PSP Global shortwave radiation - W/m2 0.2 sps 25
Pyrgeometer  K&Z CG 4 Global longwave radiation - W/m2 0.2 sps 6
Pyrgeometer Eppley PIR Global longwave radiation - W/m2 0.2 sps 10
Pyranometer SPN1 Global and Diffuse irradiance - W/m2 ? ?
Soil temperature profile sensor NCAR Soil Probe Soil temperature - deg C 0.2 sps 31
Campbell Scientific Heat flux plate HFT-3 Soil heat flux - W/m2 0.2 sps 31
Soil moisture Decagon EC-5 Soil moisture - % vol 0.2 sps 30
Soil moisture TRIME-FM w/P3 and T3 probes Soil moisture - % vol manual 1
Soil thermal properties Hukseflux TP01 conductivity, diffusivity, heat capacity 0.2 sps 31
Precipitation/Present Weather Parsivel2 Hydrometeor size and velocity distribution & Rain Rate 0.0167 sps 30
Wetness Decagon Qualitative-can deduce type 0.2 sps 30
 

ISFS measurement methods in a nutshell

  • Flux measurements made by ISFS utilize the eddy-correlation technique. Momentum flux is determined from the covariance between the vertical and horizontal velocity fluctuations measured by the 3-dimensional sonic anemometers. Sensible heat flux is determined from the covariance between measured vertical velocity and temperature fluctuations. Latent heat and carbon dioxide flux is determined from the covariance between measured vertical velocity and humidity or carbon dioxide fluctuations.
  • Measurement of fluxes of trace chemical species are obtained from correlating fluctuations from chemical species sensors with those from the ISFS velocity sensors. ISFS has several varieties of CO2 sensors for this purpose. Other chemical species measurements require user-supplied sensors which typically can be readily interfaced to ISFS. In chemical flux determination, delay times through inlet tubes can be measured and compensated for in the processing.
  • Tilt corrections for the sonic anemometer are applied in the software. Over uniformly flat terrain, the tilt correction puts the anemometers into a coordinate system parallel to the surface. In complex terrain, signals from two-axis level sensors are used to orient the sonic anemometers to gravity. Note also that the sonic anemometers make a virtual temperature measurement, Tc, reported in degrees Celsius. We maintain software to remove the moisture contribution to Tc from the sensible heat flux computation based on colocated latent heat flux measurements.
  • Mean temperature and humidity measurements are made with a commercial solid-state temperature/relative humidity sensor in an aspirated radiation shield developed by us to operate at relatively low power.
  • Measurement of the surface energy balance is achieved using up-looking and down-looking pairs of short and long-wave radiometers (either individual component or in an integrated 4-component radiometer) in tandem with soil heat flux plates and soil temperature sensors. Soil heat capacity also is measured to complete the calculation of heat storage above the soil heat flux plates.

Retired ISFS Sensors

Sensor Brand or Model Parameter Rate #
3-D sonic anemometer ATI-K u, v, w - m/s; Tv - deg C 20 sps 5
3-D sonic anemometer NCAR NUW u, v, w - m/s; Tv - deg C 20 sps 5
3-D sonic anemometer 1012R2A u, v, w - m/s; Tv - deg C 21 sps 1
1-D sonic anemometer ATI w - m/s; Tv - deg C 20 sps  
Prop-vane anemometer 9101 U, V - m/s 5 sps 11
H2O/CO2 Open-path Gas Analyzer LI-7500 H2O/CO2 concentration 20 sps 5
IR H2O/CO2 analyzer (closed-path) 7000 H2O/CO2 concentration 20 Hz 1
IR CO2 analyzer (closed path) 6251 density - gm/m3 10 Hz 1
Infrared CO2 analyzer (closed path) DX6100 density - gm/m3 10 Hz 1
Pressure sensor PTB100B Pressure - mb 1 Hz 1
Pressure sensor PTB220B Pressure - mb 1 Hz 9
Pressure sensor PTB210 Pressure - mb 1 Hz 30
Hygrothermometer 50Y Humitter T - deg C; RH -% 1 Hz 14
Dew Point   Dew point - deg C 1 Hz 1
Surface temperature sensor 4000.4ZL Surface temperature - deg K 1 sps 10
Soil temperature sensor ?? Soil temperature - deg C 1 Hz 12
Soil moisture EC-20 Soil moisture - % vol 1 Hz 10
Soil moisture CS-615 Soil moisture - % vol 1 Hz ~10
Net Radiometer Q*7 Net radiation - W/m2 1 Hz 19
PAR radiometer Quantum (LI-190SA) PAR radiation - W/m2 1 Hz 6
precipitatio NOAH II w/ Lexan wind screen Equivalent water depth - 0.01 inch events 3
 

Other sensors that we've used but do not have

Sensor Brand or Model Parameter Rate #
UV absorption hygrometer KH20 vapor density - gm/m3 60 sps 12
Soil Temperature sensor CS107 soil temperature (C) 1 Hz  
Soil Potential sensor CS229 soil moisture 1 Hz  
Ultraviolet radiometer TUVR ultraviolet radiation - W/m2 1 Hz 1
Rain gauge (Optical - ORG)   rainfall rate - mm/hr 1 Hz 1
Snow depth gauge (Ultrasonic) SR50 snow depth - mm 1 Hz 1
Dual beam ozone analyzer 49 O3 - ppb 1 Hz 1
carbon monoxide analyzer 48 CO 1 Hz 1
condensation nucleus counter 3760 CNC condensation nuclei 1 Hz 1
precipitation Tipping bucket Equivalent water depth - 0.01 inch events 29