TAO Sensor Specifications

The sensor specifications for all TAO payloads are listed in the tables below.

TAO Recap Mooring Sensors

MeasurementSensor TypeManufacture/Model #ResolutionRangeAccuracy
Wind SpeedPropellerRM Young/051030.166 m/s0 to 100 m/s±0.3 m/s or 1%
Wind DirectionVaneRM Young/051030.1°0 to 359°±3°
Air TemperaturePT100 1/3 DIN Class BRotronic/HC2A-S30.01°C-40 to +60 °C±0.2 °C
Relative HumidityHygromer C94Rotronic/HC2A-S30.01% RH0 to 100% RH±1.0% RH
PrecipitationCapacitanceRM Young/50203-340.01 mm0 to 50 mm±1 mm
Downwelling Shortwave RadiationPyranometerKipp and Zonen/ SMP10-V1 W/m2-400 to 4000 W/m2±3.0%
Downwelling Longwave RadiationPyranometerKipp and Zonen/SGR4-V1 W/m20 to 1000 W/m2±3.0%
Surface Air PressureTrench Etched Resonant Pressure SensorDruck/TERPS RPS-DPS 81000.1 hPa750 to 1150 hPa±0.1 hPa
Sea Surface TemperatureThermistorSeabird/SBE 37-SM0.001 °C-5 to 35 °C±0.002 °C
Sea Surface ConductivityInternal field conductivity cellSeabird/SBE 37-SM0.00001 S/m0 to 7 S/m±0.0003 S/m
Ocean TemperatureThermistorSeabird/SBE 39plus-IM or SBE 37-IM0.001°C-5 to 35 °C±0.002 °C
Ocean ConductivityInternal field conductivity cellSeabird/SBE 37-IM0.00001 S/m0 to 7 S/m±0.0003 S/m
Ocean Pressure (Hydrostatic)Strain element within silicon diaphragmSeabird/SBE 39plus-IM0.012 dBar0 to 600 dBar±0.6 dBar
Ocean Current Speed (Point Source)Acoustic DopplerNortek/Aquadopp 2MHz1 mm/s0 to 2.5 m/s±0.5 cm/s or ±1% of measured value
Ocean Current Direction (Point Source)Acoustic DopplerNortek/Aquadopp 2MHz0.01°0 to 359°±2° for tilt <30°
Ocean Current Speed (Profiler)Acoustic DopplerNortek/Aquadopp Profiler 400kHz1 mm/s0 to 2.5 m/s±0.5 cm/s or ±1% of measured value
Ocean Current Direction (Profiler)Acoustic DopplerNortek/Aquadopp Profiler 400kHz0.01°0 to 359°±2° for tilt <30°
Compass Heading3-axis, tilt-compensated digital magnetometerSTMicroelectronics/ LSM303AGR1°0 to 359°±2°

TAO Refresh Mooring Sensors

MeasurementSensor TypeManufacture/Model #ResolutionRangeAccuracyNotes
Wind SpeedPropellerRM Young/051030.2 m/s0 to 35 m/s0.3 m/s or 3%8
Wind DirectionVaneRM Young/051031.4°0 to 359°5°8
Air TemperaturePt100 RTDRotronic/MP101A0.01 °C-40 to +60 °C0.2 °C8
Relative HumidityHygromer C94Rotronic/MP101A0.4%0 to 100%2%8
PrecipitationCapacitanceRM Young/502030.2 mm0 to 50 mm1 mm3, 4
Downwelling Shortwave RadiationPyranometerEppley Laboratory/PSP0.4 W/m20 to 1600 W/m2±1%3
Downwelling Longwave RadiationPyranometerEppley Laboratory/PIR0.1 W/m20 to 500 W/m2±1%3, 4
Surface Air PressurePressure TransducerParoscientific/MET1-20.1 hPa800 to 1100 hPa0.1 hPa or 0.01%3
Sea Surface TemperatureThermistorSeabird/SBE 370.001 °C-5 to +35 °C0.01 °C5, 8
SalinityInternal field conductivity cellSeabird/SBE 370.00001 S/m0 to 7 S/m0.02 psu1, 8, 9
Temperature (Ocean)ThermistorSeabird/SBE 39IM0.001 °C-5 to +35 °C0.01 °C5, 6
Pressure (hydrostatic)Strain element within silicon diaphragmSeabird/SBE 39IM (Druck sensor)0.002% full scale0 to 600 dBar0.1% full scale7
Ocean Current SpeedDoppler Current MeterSonTek/Argonaut MD0.1 cm/s0 to 600 cm/s5 cm/s2
Ocean Current DirectionDoppler Current MeterSonTek/Argonaut MD0.1°0 to 359°±5°2
Compass Heading3-axis, tilt-compensated digital compassSpartan 30000.1°0 to 359°0.8° 
×

Surface salinity measured at all sites. Subsurface capability available at selected sites at depths 10, 20, 40, 60, 80 or 10, 25, 75, 100, 125 m.

 ×

For point velocity measurements, current meters shall be placed at 1 to 5 depths in the upper 200 m with at least one within 10 m of the surface. Current should be measured at all flux reference sites and at other selected sites.

 ×

At flux reference sites only.

 ×

Required only if an outside agency provides longwave radiation and rain sensors.

 ×

SBE 37 Micro CAT and SBE 39’s thermistor accuracy and stability (typical drift is less than 0.002 °C per year).

 ×

Subsurface temperature available at 10 depths on mooring.

 ×

The SBE 39’s optional pressure sensor, developed by Druck, Inc., Compensation of the temperature influence on pressure offset and scale is performed by the SBE 39’s CPU.

 ×

Sensor in use on Legacy ATLAS moorings.

 ×

Salinity is computed from measurements of temperature, pressure, and conductivity using the Practical Salinity Scale (PSS-78) and therefore salinity error is a function of the errors in the measurement of temperature, pressure and conductivity. For NDBC TAO Refresh, conductivity and temperature are measured on TAO refresh buoys near the ocean surface and salinity is computed using an assumed pressure at nominal depth, with pressure error assumed to be zero. Conductivity and temperature accuracies are as stated for the SBE-37 Conductivity-Depth Sensor. In computing salinity using PSS-78, temperature must first be converted to temperatures based on the International Practical Temperature Scale (IPTS-68) on which the PSS-78 is based. The TAO Refresh Conductivity-Temperature sensor measures temperature in the International Temperature Scale (ITS-90) and is reported in ITS-90. In computing salinity, temperature is converted from the ITS-90 to IPTS-68 prior to the salinity computation.

NextGeneration ATLAS Mooring Sensors

Measurement Sensor type Manufacturer/Model # Resolution Range Accuracy Notes
Wind speed Propeller R. M. Young: 05103 0.2 m/s 0.4-36 m/s ±0.3 m/s or 3% [7]
Wind direction Vane R. M. Young: 05103 1.4° 0-355° 5°-7.8° [7]See also footnote to [7]
Wind direction Fluxgate compass E.G.and G. or KVH: 63764 or LP101-5 1.4° 0-359° 5°-7.8° [7] See also footnote to [7]
Air temperature Pt-100 RTD (Resistance Temperature Recorder) Rotronic Instrument Corp.: MP-100 0.01°C 0-40°C ±0.2°C [12]
Relative humidity Capacitance Rotronic Instrument Corp.: MP-100 0.4 %RH realtime

0.02 %RH delay mode		 0-100 %RH ±2.7 %RH [12]
Rainfall Capacitance R. M. Young: 50203-34 0.2 mm/hr 0-50 mm ±0.4 mm/hr on 10 min filtered data [6]
Downwelling shortwave radiation Pyranometer Eppley Laboratory: PSP-TAO, Delrin case 0.4 W/m2 0-1600 W/m2 ±1%
Downwelling longwave radiation Pyrgeometer Eppley Laboratory: PIR-TAO, Delrin case, 3-output (1) 0.1 W/m2

0.03°C		 200 W/m2

@ 20°C (thermopile only)		 ±1% Nominal calibration values used for case and dome thermistors
Barometric pressure Pressure transducer Paroscientific: MET1-2 0.1 hPa 800-1100 hPa ±0.01% of reading
Sea surface and subsurface temperature Thermistor PMEL: NX ATLAS using YSI (Yellow Springs Instruments) thermistor 46006 0.001°C 0-40°C ±0.02°C [9]
Sea surface and subsurface temperature Thermistor Sea Bird Electronics: SBE16, SBE37 0.001°C -5-35°C ±0.003°C [3]
Salinity Internal field conductivity cell Sea Bird Electronics: SBE16 (Seacat) 0.0001 S/m 0-6 S/m ±0.02 psu [3] Based on SBE16 only. SBE37 assumed comparable.
Salinity Internal field conductivity cell SBE37 (Microcat) 0.00001 S/m 0-6 S/m ±0.02 psu [3] Based on SBE16 only. SBE37 assumed comparable.
Salinity Internal field conductivity cell Sea Bird cell with ATLAS module 0.002 S/m 0-6 S/m ±0.02 psu [3] Based on SBE16 only. SBE37 assumed comparable.
Water pressure Transducer Paine: 211-30-660-01 0.03 psi 0-1000 psi ±0.25% full scale (1000psi)
Ocean current (profile) Acoustic Doppler Current Profiler RD Instruments: Narrow band, 150 kHz 0.1 cm/s

0.006		 0-256 cm/s ±5 cm/s,

±2.5°		 [5] [11]
Ocean current (single point) Doppler Current Meter SonTek: Argonaut 0.1 cm/s

0.1°		 0-600 cm/s ±5 cm/s,

±5°		 [10]

Standard ATLAS and Early Current Meter Mooring Sensors

Measurement Sensor type Manufacturer/Model # Resolution Range Accuracy Notes
Wind speed Propeller R. M. Young: 05103 0.2 m/s 0.4-36 m/s ±0.3 m/s or 3% [7]
Wind direction Vane R. M. Young: 05103 1.4° 0-355° 5°-7.8° [7] See also footnote to [7]
Wind direction Fluxgate compass E.G.and G. or KVH: 63764 or LP101-5 1.4° 0-359° 5°-7.8° [7] See also footnote to [7]
Air temperature Pt-100 RTD (Resistance Temperature Detector) Rotronic Instrument Corp.: MP-100 0.04°C 0-40°C ±0.2°C [2]
Relative humidity Capacitance Rotronic Instrument Corp.: MP-100 0.4 %RH realtime

0.02 %RH delay mode		 0-100 %RH ±2.7 %RH [2]
Downwelling shortwave radiation (Current Meter Moorings) Pyranometer Eppley Laboratory: PSP 1.3 W/m2 0-1600 W/m2 ±2% [1], [2]
Sea surface temperature Thermistor PMEL: Standard ATLAS SST sensor using YSI (Yellow Springs Instruments) thermistor 46006 0.001°C 14-32°C ±0.03°C [2]
Sea surface temperature Thermistor PMEL: Current meter mooring SST sensor using YSI thermistor 46006 0.001°C 14-32°C ±0.01°C [2]
Subsurface temperature Thermistor PMEL: Standard ATLAS sensor using YSI thermistor 46006 0.001°C 2-35°C ±0.09°C [2]
Subsurface temperature Thermistor PMEL: Mini Temperature Recorder (MTR) using YSI thermistor 46006 0.001°C -2-34°C ±0.01°C Accuracy based on unpublished PMEL calibrations
Subsurface temperature Thermistor EG&G VACM 0.001°C 1-31°C ±0.05°C [8]
Subsurface temperature Thermistor EG&G VMCM 0.006°C 1-31°C ±0.05°C [8]
Subsurface temperature Thermistor Sea Data TR-2, TDR-2 0.01°C -5-35°C ±0.05°C [8]
Sea surface and subsurface temperature Thermistor Sea Bird Electronics: SBE16, SBE37 0.001°C -5-35°C ±0.003°C [3]
Salinity Internal field conductivity cell Sea Bird Electronics: SBE16 (Seacat) 0.0001 S/m 0-6 S/m ±0.02 psu [3]
Water pressure Transducer Paine: 211-30-660-01 0.03 psi 0-1000 psi ±0.25% full scale (1000psi)
Ocean current (single point) Savonious rotor and vane EG&G VACM 0.005 cm/s

2.8°		 2-300 cm/s ±3-7 cm/s,

±5.6°		 [4]
Ocean current (single point) Orthogonal Propellers EG&G VMCM 0.01 cm/s

1.4°		 0.9-340 cm/s ±3-7 cm/s,

±2.5°		 [4]
Ocean current (profile) Acoustic Doppler Current Profiler RD Instruments: Narrow band, 150 kHz 0.1 cm/s

0.006		 0-256 cm/s ±5 cm/s,

±2.5°		 [5]

References

[1] Fairall, C. W., P. O. G. Persson, E.F. Bradley, R. E. Payne and S. P. Anderson, 1998: A new look at calibration and use of Eppley Precision Radiometers. Part I: Theory and Application. J. Atmos. Ocean. Tech., 15, 1229-1242.

[2] Freitag, H.P., Y. Feng, L.J. Mangum, M.P. McPhaden, J. Neander, and L.D. Stratton, 1994: Calibration procedures and instrumental accuracy estimates of TAO temperature, relative humidity and radiation measurements. NOAA Tech. Memo. ERL PMEL-104, 32 pp.

[3] Freitag, H.P., M.E. McCarty, C. Nosse, R. Lukas, M.J. McPhaden, and M.F. Cronin, 1999: COARE Seacat data: Calibrations and quality control procedures. NOAA Tech. Memo. ERL PMEL-115, 89 pp.

[4] Halpern, D., 1987: Comparison of upper ocean VACM and VMCM observations in the equatorial Pacific. J. Atmos. Ocean. Tech., 4, 84-93.

[5] Plimpton, P.E., H.P. Freitag, and M.J. McPhaden, 1995: Correcting moored ADCP data for fish-bias errors at 0°,110°W and 0°,140°W from 1990 to 1993. NOAA Tech. Memo. ERL PMEL-107, 49 pp.

[6] Serra, Y.L., P.A'Hearn, H.P. Freitag, and M.J. McPhaden, 2001: ATLAS self-siphoning rain gauge error estimates. J. Atmos. Ocean. Tech.,18, 1989-2002.

[7] Freitag, H.P., M. O'Haleck, G.C. Thomas, and M.J. McPhaden, 2001: Calibration procedures and instrumental accuracies for ATLAS wind measurements. NOAA. Tech. Memo. OAR PMEL-119, NOAA/Pacific Marine Environmental Laboratory, Seattle, Washington, 20 pp.

Footnote: This study discovered a systematic error in standard and NextGeneration ATLAS wind directions of approximately 6.8° in the counterclockwise direction. This error was present possibly as far back as 1984. Modifications were made to the NextGeneration ATLAS system in 2000 to correct this error in subsequent deployments, and archived NextGeneration ATLAS wind directions were corrected (both daily averages and high resolution datasets) on 28 March 2002. Standard ATLAS wind directions have not been corrected in the archives since the exact time when the error began to affect the measurements is unknown. Standard ATLAS were used exclusively between 1984 and 1996 when NextGeneration ATLAS moorings began to replace them. By November 2001, the standard ATLAS had been phased out and the array was comprised entirely of NextGeneration systems. Expected RMS error for standard ATLAS wind direction is 7.8° (of which 6.8° is a bias) while expected RMS error for NextGeneration ATLAS wind directions is about ±5° with no appreciable bias.

[8] McCarty, M.E., and M.J. McPhaden, 1993: Mean seasonal cycles and interannual variations at 0, 165E during 1986-1992. NOAA Tech. Memo. ERL PMEL-98, 64pp.

[9] A'Hearn, P.N., H.P. Freitag, and M.J. McPhaden, 2002: ATLAS module temperature bias due to solar heating. NOAA Tech. Memo OAR PMEL-121, NOAA/Pacific Marine Environmental Laboratory, Seattle, WA, 24 pp.

[10] Freitag, H.P., M.J. McPhaden, C.Meinig, and P.Plimpton, 2003: Mooring motion bias of point Doppler current meter measurements. In: Proceedings of the IEEE Seventh Working Conference on Current Measurement Technology, San Diego, CA, 13-15 March 2003, IEEE, Piscataway, NJ, 155-160.

[11] Plimpton, P.E., H.P. Freitag, and M.J. McPhaden, 2004: Processing of subsurface ADCP data in the equatorial Pacific. NOAA Tech. Memo OAR PMEL-125, NOAA/Pacific Marine Environmental Laboratory, Seattle, WA. 41pp.

[12] Lake, B.J., S.M. Noor, H.P. Freitag, and M.J. McPhaden, 2003: Calibration procedures and instrumental accuracy estimates of ATLAS air temperature and relative humidity measurements. NOAA Tech. Memo. OAR PMEL-123, NOAA/Pacific Marine Environmental Laboratory, Seattle, WA, 23 pp.