Direct Covariance Flux Instrument
Package Specification
Control Number: 3305-00004
Version: 1-00
Date: July 13, 2011
Coastal and Global Scale Nodes
Ocean Observatories Initiative
Woods Hole Oceanographic Institution
Oregon State University
Scripps Institution of Oceanography
Template: 3101-00074, Ver 1-01
Revision History
Version
Description
Originator
0-00
Initial Draft
0-01
Updates and edits
R. Weller
0-02
Checked specifications, revised
R. Weller
0-03
Separate fast response hygrometer
as separate specification.
R. Weller
1-00
Initial release
R. Weller
i
ECR No.
1303-00378
Release Date
13 July 2011
Signature Page
This document has been reviewed and approved for release.
OOI Senior Systems Engineer:
ii
Table of Contents
1.0
General................................................................................................................................... 1
1.1 Ocean Observatories Initiative (OOI) Overview ................................................................. 1
1.2 Document Scope and Purpose .......................................................................................... 1
1.3 Documents ........................................................................................................................ 2
1.3.1 Informational ............................................................................................................. 2
1.3.2 Applicable ................................................................................................................. 3
1.4 Definitions ......................................................................................................................... 3
1.4.1 Glossary and Acronyms ............................................................................................ 3
1.4.2 Conventions .............................................................................................................. 4
2.0 Specifications ........................................................................................................................ 5
2.1 Measurement .................................................................................................................... 5
2.1.1 Turbulent wind velocity, each of 3-components......................................................... 5
2.1.2 Turbulent Air Temperature ........................................................................................ 6
2.1.3 Relative humidity ...................................................................................................... 6
2.1.4 Barometric pressure ................................................................................................. 7
2.1.5 Three-axis Linear and Angular Platform motion ........................................................ 8
2.2 Operational ........................................................................................................................ 9
2.2.1 Operational Depth Range ......................................................................................... 9
2.2.2 Environmental ........................................................................................................... 9
2.2.3 Service Requirements............................................................................................... 9
2.2.4 Calibration Requirements ......................................................................................... 9
2.2.5 Deployment Interval ................................................................................................ 10
2.2.6 Duty cycle ............................................................................................................... 10
2.3 Mechanical/Physical ........................................................................................................ 10
2.3.1 Materials ................................................................................................................. 10
2.3.2 Size ........................................................................................................................ 10
2.3.3 Weight .................................................................................................................... 10
2.4 Electrical.......................................................................................................................... 10
2.4.1 Interference Requirements ..................................................................................... 10
2.4.2 Voltage ................................................................................................................... 10
2.4.3 Current ................................................................................................................... 10
2.4.4 Power ..................................................................................................................... 10
2.4.5 Grounding ............................................................................................................... 10
2.4.6 Battery Life ............................................................................................................. 10
2.4.7 Modes/State of Operation ....................................................................................... 11
2.4.8 Isolation .................................................................................................................. 11
2.4.9 Interface to hygrometer ........................................................................................... 11
2.5 Data Storage and Processing .......................................................................................... 11
2.5.1 Storage Capacity .................................................................................................... 11
2.5.2 Data Averaging ....................................................................................................... 11
iii
2.5.3 Onboard Data Processing ....................................................................................... 11
2.5.4 Post-recovery Data Processing............................................................................... 11
2.6 Software/Firmware .......................................................................................................... 11
2.7 Platform Interfaces .......................................................................................................... 12
2.7.1 Mechanical ............................................................................................................. 12
2.7.2 Electrical ................................................................................................................. 12
2.7.3 Data and Communication ....................................................................................... 12
2.8 Compliance ..................................................................................................................... 13
2.9 Safety .............................................................................................................................. 13
2.10 Shipping and Storage ...................................................................................................... 13
2.10.1 Shipping .................................................................................................................. 13
2.10.2 Storage ................................................................................................................... 13
2.10.3 Safe Handling ......................................................................................................... 14
2.11 Identification .................................................................................................................... 14
2.11.1 Physical Markings ................................................................................................... 14
2.12 Quality ............................................................................................................................. 14
2.12.1 Product Quality ....................................................................................................... 14
3.0 Documentation and Support .............................................................................................. 14
4.0 Appendices .......................................................................................................................... 15
4.1 Preferred OOI Standard Connector types. ....................................................................... 15
iv
1.0
General
1.1
Ocean Observatories Initiative (OOI) Overview
Although the ocean is central to the habitability of our planet, it is largely unexplored. Biological,
chemical, physical, and geological processes interact in complex ways in the ocean, at the
seafloor, and at the air-sea interface. Our ability to learn more about these processes is severely
limited by technical infrastructure, and developing a more fundamental scientific understanding of
these relationships requires new and transformational approaches to ocean observation and
experimentation.
The Ocean Observatories Initiative (OOI) will lay the foundation for future ocean science
observations. OOI will enable powerful new scientific approaches by transforming the community’s
focus from expedition-based data gathering to persistent, controllable observations from a suite of
interconnected sensors. The OOI's networked sensor grid will collect ocean and seafloor data at
high sampling rates over years to decades. Researchers will make simultaneous, interdisciplinary
measurements to investigate a spectrum of phenomena including episodic, short-lived events
(tectonic, volcanic, oceanographic, biological, and meteorological), and more subtle, longer-term
changes and emergent phenomena in ocean systems (circulation patterns, climate change, ocean
acidity, and ecosystem trends).
The OOI will enable multiple scales of marine observations that are integrated into one observing
system via common design elements and an overarching, interactive cyberinfrastructure. Coastalscale assets of the OOI will expand existing observations off both U.S. coasts, creating focused,
configurable observing regions. Regional cabled observing platforms will ‘wire’ a single region in
the Northeast Pacific Ocean with a high speed optical and high power grid. Global components
address planetary-scale changes via moored open-ocean buoys linked to shore via satellite.
Through a unifying cyberinfrastructure, researchers will control sampling strategies of experiments
deployed on one part of the system in response to remote detection of events by other parts of the
system.
A more detailed discussion of the Oceans Observatories Initiative can be found in the OOI Final
Network Design.
1.2
Document Scope and Purpose
The purpose of this specification is to provide the requirements for a direct covariance flux
instrument package to be purchased for use on the Coastal and Global Scale Nodes (CGSN) of
the Ocean Observatories Initiative. Direct covariance flux instrument packages will be mounted on
surface buoys that will be deployed in both coastal regions (depths up to ~600 m) and open ocean
regions (at latitudes above 40 degrees). Coastal and Global buoys will include a tower for
mounting sensors at a height of ~3-5 m above water level. Buoys will be designed to orient
themselves relative to the wind.
This document describes the physical, functional and electrical characteristics of direct covariance
flux instrument packages required by CGSN.
Direct covariance flux systems (DCFS) measure the vertical fluxes associated with eddies in the
flow over the ocean. When done well, they provide a direct measure of vertical transports or
fluxes. The bulk meteorological system provides a second way to measure the air-sea fluxes, but
the bulk method relies on parameterizations. These parameterizations and hence the accuracy of
the bulk methods are not well known in high winds (>20 m s-1) and energetic and/or changing
-1-
surface wave conditions. Thus, the OOI requires a DCFS instrument package to ensure the
requirements to observe the air-sea fluxes are met in high wind and sea state conditions.
At the heart of a DCFS is the ability to measure the fluctuating or turbulent components of the wind
(u’, v’, and w’ which are respectively the turbulent east, turbulent north, and turbulent vertical wind
velocity components) and the desired fluctuating scalar quantity (e.g. T’, q’, CO2’, where these are
temperature, specific humidity and CO2 fluctuations, respectively). The challenge for a buoymounted DCFS system is that it measure wind in the moving reference frame of the buoy, so the
buoy DCFS must correct relative turbulent wind for the rotation and translation of the buoy. The
measurements of the turbulent components and the corrections are done at a rate of about 10 to
20 Hz.
A buoy-based eddy covariance flux system thus consists of a 3-axis sonic anemometer logging
fast wind components (u,v,w) and sonic temperature (Ts) at 10 to 20 Hz plus a fast hygrometer
(also 10 to 20 Hz). A fast platform motion-measuring system is required to remove wave-induced
motions and rotate the wind components into a fixed-earth coordinate system. The motion system
must measure 3-axis linear accelerations and 3-axis angular rates with software to integrate these
to 3-axis linear motions and pitch, roll, and heading angles. Motion corrections must be done to
the raw sonic time series. A typical fast hygrometer uses nod-dispersive IR (NDIR) absorption
along an optical path of 10-20 cm. Contamination of the optics by sea spray and other sources
(e.g., birds) may rapidly degrade performance. The fluxes are obtained by cross-correlating the
true vertical velocity with the true horizontal wind components, fast temperature, and fast humidity.
Additional variables (mean air temperature, humidity, and pressure) may be required to
interpret/correct the fluxes.
Because fast response hygrometers are also used in land-based direct covariance flux systems,
there are commercial sources for these instruments addressing a marketplace much larger than
that of buoy and ship-based DCFS systems. Continued evolution and improvement is anticipated
in fast response hygrometers, so the approach taken in developing an OOI specification of a DCFS
is to specify a buoy-based system with sonic anemometer, motion measurement and correction,
and ancillary mean sensors for humidity, temperature, and pressure that is plug-and-play
compatible with commercially available fast response hygrometers. The acquisition of the fast
response hygrometer from a commercial source also allows for specifying the calibration,
refurbishment, repair, and upgrades services to be needed by the OOI to be part of the acquisition
of the fast response hygrometer, removing the significant burden of supporting the least robust
component of the DCFS system from the OOI DCFS supplier. This is important because the
market for buoy and ship DCFS systems is small, and potential respondents to an RFP for a buoybased DCFS may not have their own capability to support and service the fast response
hygrometer.
1.3
Documents
1.3.1 Informational
The documents listed in this section are for informational purposes only and may not have
been referenced in this specification.

Consortium for Ocean Leadership, Inc. 2010. Final Network Design. Washington, DC.
[Online] Available: http://www.oceanleadership.org/programs-and-partnerships/oceanobserving/ooi/network-design/

Burba, G. and D. Anderson (2010) A Brief Practical Guide to Eddy Covariance Flux
Measurements: Principles and Workflow Examples for Scientific and Industrial
Applications. www.licor.com. 213 pp.
-2-

Campbell Scientific, Inc. (1998) Instruction Manual: Eddy Covariance System CA27 and
KH20, www.campbellsci.com.

Edson, J. B., A. A. Hinton, K. E. Prada, J. E. Hare, and C.W. Fairall (1998) Direct
Covariance Flux Estimates from Mobile Platforms at Sea. Journal of Atmospheric and
Oceanic Technology, 15, 547-562.

Frederickson, P. A., K. L. Davidson, F. K. Jones, and T. Neta, (2001) Naval Postgraduate
School FLUX Buoy Data Report for the MUSE Deployment, August-September 2000,
Monterey Bay, California. Technical Report, Naval Postgraduate School, 19 pp.

Gill, G. C. (1976) Development and testing of a no-moving parts static pressure inlet for use
on ocean buoys. NOAA Data Buoy Office Progress Rep. 01-6-038-115, 43 pp.

Launiainen, S., J, Rinne, J. Pumpanen, L. Kulmala, P. Kaori, P. Keronen, E. Silviola, T.
Pohja, P. Hari, and T. Vesala (2005) Eddy covariance measurements of CO2 and sensible
and latent heat fluxes during a full year in a boreal pine forest trunk-space. Boreal
Environment Research, 10, 569-588.
1.3.2
N/A
1.4
Applicable
Definitions
1.4.1 Glossary and Acronyms
 Accuracy – Closeness of the agreement between the result of a measurement and the
value of the measurand (or true value of the measurement). (Taylor and Kuyatt, 1994)

Burst Sampling – Intermittent rapid sampling at or near the maximum sampling rate for
short intervals between longer quiescent periods.

CGSN – Coastal and Global Scale Nodes

DCFS – Direct Covariance Flux System

EIA – Electronics Industries Association

Instrument – A device that contains one or more sensors and a method for converting the
information from the sensor into a transmittable and storable form.

Objective Value – The desired value of a technical parameter. This value, if provided, may
be more challenging to achieve than the Threshold value. It is a goal, not a requirement,
for the instrument.

OOI – Ocean Observatories Initiative

Operate – Correctly performing designed functionality.

Precision – The closeness of agreement between independent measurements obtained
under stipulated conditions of repeatability, generally expressed as a standard deviation (or
standard uncertainty) of measurement results (Taylor and Kuyatt, 1994). Used as a
measure of stability of an instrument/sensor and its capability of producing the same
measurement over and over again for the same input signal.

Resolution – The smallest amount of input signal change that the instrument/sensor can
detect reliably.
-3-

Response Time – The time required for an output to reach a specified fraction of its final
value as a result of a step change in input.

PSS – Practical Salinity Scale, the UNESCO Practical Salinity Scale of 1978 (PSS78)
defines salinity as a dimensionless conductivity ratio.

RMS – Root Mean Square

Sensor – A device that will convert a physical phenomenon into an electrical signal that can
in turn be digitized through the use of an analog to digital converter. A sensor is normally
housed in an instrument. Data coming from sensors is normally raw and needs to be
calibrated.

Survive – Experience an event without major loss of hardware. System may experience
loss of functionality requiring repair to return to normal mode functionality. An example of
this is knockdown of a global mooring or loss of some part of the mooring resulting in the
instrument descending to the bottom. Any internal memory in the instrument shall remain
accessible, but the sensors may need to be replaced to return to normal functionality.

Sustain – Experience an event (environmental extreme or condition) without permanent
loss of normal mode functionality. System may experience reduction of functionality during
event.

Threshold Value – The minimal limiting acceptable performance value that this item must
meet of a technical parameter. If this item does not meet the performance as specified by
the threshold value it may not be sufficient for inclusion in the OOI system.
1.4.2 Conventions
All values contained in this document are Threshold Values unless specifically stated
otherwise.
Specification items are assigned unique identification numbers specific to this document. Items
tied directly to requirements maintained in the OOI requirements database are followed by the
requirement number in brackets (e.g., [L4-CG-IP-RQ-XXX]). The requirement number is
intended for internal OOI use only.
-4-
2.0
Specifications
2.1
Measurement
Values provided are threshold unless otherwise stated.
2.1.1 Turbulent wind velocity, each of 3-components.
Wind speed is the square root of the sum of the squares of the three components. The
individual components can be negative or positive while the speed/velocity is positive by
definition.
a) Measurement with unit(s)
Turbulent wind velocity, 3 component (speed in m/s, direction in degrees)
b) Minimum Value
TVEL-001
Turbulent wind velocity instruments shall measure wind speed to a
minimum value of 0 m/s. [L4-CG-IP-RQ-339]
TVEL-002
Turbulent wind velocity instruments shall measure wind direction to a
minimum value of 0° [L4-CG-IP-RQ-630]
c) Maximum Value
TVEL-003
Turbulent wind velocity instruments shall measure wind speed to a
maximum value of 65 m/s. [L4-CG-IP-RQ-339]
TVEL-004
Turbulent wind velocity shall measure wind direction to a maximum value
of 360° [L4-CG-IP-RQ-360]
d) Accuracy
TVEL-005
Turbulent wind velocity instruments shall have a wind speed accuracy of
better than +/- 0.18 m/s at speeds of 12 m/s or less, and 1.5% RMS at
speeds greater than 12 m/s. [L4-CG-IP-RQ-334]
TVEL-006
Turbulent wind velocity instruments shall have a wind direction accuracy
of 2° [L4-CG-IP-RQ-335]
e) Precision
N/A
f) Resolution
TVEL-007
Turbulent wind velocity instruments shall have a wind speed resolution of
0.01 m/s. [L4-CG-IP-RQ-337]
TVEL-008
Turbulent wind velocity instruments shall have a wind direction resolution
of 0.1°. [L4-CG-IP-RQ-338]
g) Drift
TVEL-009
Turbulent wind velocity instruments shall have an annual wind speed drift
of less than 0.01 m s-1 per year. [L4-CG-IP-RQ-340]
h) Response Times
N/A
i) Sampling Frequency
TVEL-010
Turbulent wind instruments shall be capable of sampling at rates of 1 Hz
to 20 Hz, inclusive. [L4-CG-IP-RQ-341]
-5-
j)
Constraints/Dependencies
TVEL-011
Turbulent wind instruments should provide ASCII digital output [RS 232,
RS422, RS485] at baud rates between 4,800 and 57,600. This is an
objective.
TVEL-012
Turbulent wind instruments should operate at temperatures between
-40°C to 70°C. This is an objective.
TVEL-013
Turbulent wind instruments should operation at humidities between 5
and 100%. This is an objective.
2.1.2 Turbulent Air Temperature
a) Measurement with unit(s)
Turbulent air temperature (temperature in °C)
b) Minimum Value
TEMP-001
Turbulent air temperature instruments shall measure temperature to a
minimum value of -30° C. [L4-CG-IP-RQ-636]
c) Maximum Value
TEMP-002
Turbulent air temperature instruments shall measure temperature to a
maximum value of 45° C. [L4-CG-IP-RQ-636]
d) Accuracy
TEMP-003
Turbulent air temperature instruments shall measure temperature with an
accuracy of 1° C. [L4-CG-IP-RQ-634]
e) Precision
N/A
f) Resolution
TEMP-004
Turbulent air temperature instruments shall measure temperature with a
resolution of 0.01° C. [L4-CG-IP-RQ-635]
g) Drift
N/A
h) Response Times
N/A
i) Sampling Frequency
TVEL-005
Turbulent air temperature instruments shall be capable of sampling rates
of 1 Hz to 20 Hz, inclusive. [L4-CG-IP-RQ-637]
j) Dependencies
N/A
2.1.3 Relative humidity
a) Measurement with units(s)
Relative Humidity (percentage)
b) Minimum Value
RHUM-001
Relative Humidity instruments shall measure humidity to a minimum
value of 0%. [L4-CG-IP-RQ-79]
-6-
c) Maximum Value
RHUM-002
Relative Humidity instruments shall measure humidity to a maximum
value of 110%. [L4-CG-IP-RQ-79]
d) Accuracy
RHUM-003
Relative Humidity instruments shall have a laboratory accuracy of +/2%. [L4-CG-IP-RQ-74]
RHUM-004
Relative Humidity instruments should have a field accuracy of +/- 5%.
This is an objective.
e) Precision
N/A
f) Resolution
RHUM-005
Relative Humidity instruments shall have a resolution of 0.1%. [L4-CGIP-RQ-75]
g) Drift
RHUM-006
Relative humidity instruments shall have an annual drift of less than
5.0%. [L4-CG-IP-RQ-318]
h) Response Times
N/A
i) Sampling Frequency
RHUM-007
Relative Humidity measurements shall be made at a frequency of once
per minute. If higher frequency measurements are possible, they shall
be boxcar averaged to provide average measurements once per minute.
[L4-CG-IP-RQ-78]
j) Dependencies
RHUM-008
Relative humidity sensors will be located in close proximity (within 10
cm) to the turbulent wind sensor to support calculation of the virtual
temperature from the sonic temperature.
k) Sea Spray Resistance
RHUM-009
Relative Humidity instrument performance shall not be affected by sea
spray. [L4-CG-IP-RQ-80]
2.1.4 Barometric pressure
a) Measurement with units(s)
Barometric Pressure (millibars)
b) Minimum Value
BARO-001
Barometric Pressure instruments shall measure pressure to a minimum
value of 850 millibars. [L4-CG-IP-RQ-71]
c) Maximum Value
BARO-002
Barometric Pressure instruments shall measure pressure to a maximum
value of 1050 millibars. [L4-CG-IP-RQ-71]
d) Accuracy
BARO-003
Barometric pressure instruments shall have a laboratory accuracy of +/0.2 millibars. [L4-CG-IP-RQ-66]
BARO-004
Barometric pressure instruments should have a field accuracy of +/-0.5
millibars. This is an objective.
-7-
e) Precision
N/A
f) Resolution
BARO-005
Barometric pressure instruments shall have a resolution of 0.1 millibars.
[L4-CG-IP-RQ-67]
g) Drift
BARO-006
Barometric pressure instruments shall have an annual drift of less than
0.5 millibars. [L4-CG-IP-RQ-317]
h) Response Times
N/A
i) Sampling Frequency
BARO-007
Barometric Pressure measurements shall be made at a frequency of
once per minute. If higher frequency measurements are possible, they
shall be boxcar averaged to provide average measurements once per
minute. [L4-CG-IP-RQ-70]
j) Dependencies
BARO-008
The input port of the Barometric Pressure sensor shall be fitted with a
Gill pressure port (Gill, 1976). [L4-CG-IP-RQ-72]
2.1.5 Three-axis Linear and Angular Platform motion
a) Measurement with units(s)
Linear and angular platform motion (m/s, deg/s); Angular position (degrees)
b) Minimum Value
MOTN-001
Linear motion sensors shall measure motion to a minimum value of -15
m/s [L4-CG-IP-RQ-650]
MOTN-002
Angular motion sensors shall measure motion to a minimum value of -60
deg/s. [L4-CG-IP-RQ-651]
MOTN-003
Angular position sensors shall measure position to a minimum value of 0
degrees. [L4-CG-IP-RQ-652]
c) Maximum Value
MOTN-004
Linear motion sensors shall measure motion to a maximum value of 15
m/s [L4-CG-IP-RQ-650]
MOTN-005
Angular motion sensors shall measure motion to a maximum value of 60
deg/s. [L4-CG-IP-RQ-651]
MOTN-006
Angular position sensors shall measure position to a maximum value of
360 degrees. [L4-CG-IP-RQ-652]
d) Accuracy
MOTN-007
Linear motion sensors shall have an accuracy of 0.04 m/s. [L4-CG-IPRQ-644]
MOTN-008
Angular motion sensors shall have an accuracy of 0.5 deg/s. [L4-CG-IPRQ-645]
MOTN-009
Angular position sensors shall have an absolute accuracy of 0.5
degrees. [L4-CG-IP-RQ-646]
e) Precision
N/A
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f)
Resolution
MOTN-010
MOTN-011
MOTN-012
Linear motion sensors shall have a resolution of 0.01 m/s. [L4-CG-IPRQ-647]
Angular motion sensors shall have a resolution of 0.004 deg/s. [L4-CGIP-RQ-648]
Angular position sensors shall have a resolution of 0.05 degrees or
better. [L4-CG-IP-RQ-649]
g) Drift
MOTN-013
Platform motion instruments shall have an angle random walk of 0.25
degrees/hr (15 degrees per hour per Hz) or better. [L4-CG-IP-RQ-653]
h) Response Times
N/A
i) Sampling Frequency
MOTN-014
Platform motion instruments shall be capable of sampling rates of 1 Hz
to 20 Hz, inclusive. [L4-CG-IP-RQ-654]
j) Dependencies
MOTN-015 Package motion will be measured close (<1 m) to the location of the
turbulent wind velocity sensor.
2.2
Operational
2.2.1
Operational Depth Range
N/A
2.2.2 Environmental
a) Salinity
N/A
b) Temperature
OPER-001
Instruments shall be capable of making air-sea measurements within an
ambient air temperature range of -30° C and +45° C. [L4-CG-IP-RQ432]
c) Biofouling
OPER-002
Sensors shall utilize bio-fouling mitigation to enable nominal operations
over the defined maintenance interval. [L4-CG-IP-RQ-446]
d) Icing
OPER-003
Instruments mounted in air shall sustain periods of icing. [L4-CG-IP-RQ405]
2.2.3
Service Requirements
N/A
2.2.4
Calibration Requirements
OPER-004
Sensors should maintain their calibration over the required deployment
intervals. This is an objective. [L4-CG-IP-RQ-286]
-9-
2.3
2.2.5
Deployment Interval
OPER-005
The designed deployment interval for instrument packages on moored
assets shall be 13 months. [L3-CG-RQ-168; L3-CG-RQ-496; L3-CGRQ-497]
2.2.6
Duty cycle
OPER-006
Mechanical/Physical
2.3.1
Materials
MECH-001
MECH-002
2.4
The Direct Covariance Flux System shall be capable of being duty cycled.
For example, operating for a period of minutes (0 to 20) every hour as
needed to achieve average power consumption over one hour of less
than 10 Watts. [L4-CG-IP-RQ-658]
2.3.2
Size
N/A
2.3.3
Weight
N/A
Instrument electronics housings shall be designed to be corrosion
resistant. [L4-CG-IP-RQ-288]
The instrument package and components mounted on surface buoys
shall be capable of surviving immersion in seawater to a depth of 5 m.
[L3-CG-RQ-886]
Electrical
2.4.1
Interference Requirements
ELEC-001
A/D converters shall be placed as close to the sensor as possible.
2.4.2
Voltage
N/A
2.4.3
Current
N/A
2.4.4
Power
ELEC-002
2.4.5
Grounding
N/A
2.4.6
Battery Life
N/A
Power consumption when on continuously shall not exceed 20 Watts.
[L4-CG-IP-RQ-657]
- 10 -
2.5
2.4.7
Modes/State of Operation
ELEC-003
Instruments shall return to a defined operational state upon being
depowered and repowered. [L4-CG-IP-RQ-447]
2.4.8
Isolation
N/A
2.4.9
Interface to hygrometer
ELEC-004
The Direct Covariance Flux System shall provide a power connection for
a commercial fast-response hygrometer capable of supplying in the
range 10-30 VDC.
ELEC-005
The Direct Covariance Flux System shall provide a serial (RS-232, RS422, RS-485) communications connection for a commercial fastresponse hygrometer capable of baud rates between 4,800 and 56,700.
Data Storage and Processing
2.5.1
Storage Capacity
DATA-001
Instruments shall provide non-volatile internal data storage. The data
storage size shall accommodate data taken at the typical rate (20 Hz)
over the duration of the deployment interval (see OPER-005).
DATA-002
The DCFS data logger shall be capable of logging raw sensor data at up
to 20Hz.
DATA-003
Instruments should internally store calibration and sensors serial
numbers. This is an objective.
2.5.2
Data Averaging
DATA-004
The instrument package shall provide data averaging capabilities such
that 1 minute averages can be obtained from higher frequency sampling.
2.5.3
Onboard Data Processing
DATA-005
The DCFS shall be capable of onboard processing to provide means,
variances, and covariances over specified blocks of time. [L4-CG-IPRQ-655]
DATA-006
2.5.4
2.6
The DCFS shall be capable of outputting processed data in near real
time. [L4-CG-IP-RQ-656]
Post-recovery Data Processing
DATA-007
The DCFS shall be provided with a software package to carry out all
processing of the raw data to yield covariance flux estimates. The
software package shall be fully documented with a copy of the code and
all of the equations and steps in the processing.
Software/Firmware
SOFT-001
Serial instruments requiring a break signal should be capable of
emulating the break by a software character sequence. This is an
objective.
- 11 -
2.7
Platform Interfaces
2.7.1
Mechanical
N/A
2.7.2
Electrical
INTF-001
INTF-002
INTF-003
The instrument package shall connect to the platform controller for power
and communications (the connector type is on the CGSN platform
controller housing are TBS and will be detailed in an interface control
document).
The instrument should include a standard type of OOI bulkhead
connector on the instrument housing (see Appendix 4.1). This is an
objective.
The instrument package shall operate from a supply voltage of either 12
VDC +/- 5% or 24 VDC +/- 5%. [L4-CG-IP-RQ-287]
2.7.3 Data and Communication
a) Timing
INTF-004
Instruments shall provide time-stamping capabilities or latency
characterization between data sampling and data output. [L4-CG-RQ450]
Preferences for instrument time stamping capabilities are as follows
(best first):
 Time stamp embedded in every data record to the design accuracy of
the instrument's clock, using ISO 8601 compliant timestamp
 Time stamp embedded in every data record to the design accuracy of
the instrument's clock, using another described, parseable timestamp
format
 Time stamp every data sequence, with fixed time between every data
record
 Fully characterize the latency between data sampling and
appearance of the data at the output connector
 Time stamp embedded in every data record, with precision that is
less than the accuracy of the instrument's clock, using ISO 8601
compliant timestamp
 Time stamp embedded in every data record, with precision that is
less than the accuracy of the instrument's clock, using another
described, parseable timestamp format.
b) Clock Synchronization
INTF-005
Instruments should have an internal clock. This is an objective.
INTF-006
Instruments with internal clocks shall be capable of time synchronization.
[L4-CG-IP-RQ-449]
c) Data Rate
INTF-007
Instruments should have a user-settable baud rate, up to 115,200 baud
for serial interfaces. This is an objective.
d) Data Format
N/A
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e) Protocols
INTF-008
Instruments with an Ethernet interface should provide an auto-discovery
mechanism, (e.g., PUCK, Universal Plug’n’Play’, ZeorConf/Bonjour).
This is an objective.
f) Physical Interface
N/A
g) Electrical Interface
INTF-009
Instruments shall communicate (Data and Commands) while deployed
with the OOI infrastructure (e.g. CI device driver or platform interface) via
at least one of the following interfaces: Ethernet (10/100 Mb), or serial
EIA standards: RS-422, RS-485, or RS-232. [ L4-CG-IP-RQ-297, L4-CGIP-RQ-291]
h) Remote Access
INTF-010
Instruments shall be capable of being remotely accessed and controlled
via the communication interface. [L4-CG-IP-RQ-294]
INTF-011
All data stored on the instrument shall be accessible remotely over the
communication interface.
INTF-012
Instruments should support remote firmware installation. This is an
objective.
i) Modes
INTF-013
Instruments should allow polled and asynchronous mode operation. This
is an objective.
2.8
Compliance
COMP-001
2.9
To the greatest extent practical, all CGSN infrastructure shall be
compatible with applicable national and international standards, including
those of the IEEE, ANSI, and IEC.
Safety
N/A
2.10 Shipping and Storage
2.10.1 Shipping
SHIP-001
SHIP-002
SHIP-003
2.10.2 Storage
SHIP-004
Instruments shall be provided with a reusable transportation case with
shock mounting.
Instrument Transportation Cases must fit within an ISO shipping
container. [L3-CG-RQ-494]
Instruments in their transportation cases shall be capable of surviving
shipping conditions defined by ASTM D4169 truck assurance level 1.
[L3-CG-RQ-432]
Instruments should be capable of being stored with out damage or
degradation between -20° and 50° C for periods of up to 12 months.
This is an objective.
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2.10.3 Safe Handling
SHIP-005
Instrument transportation cases shall have external labels specifying
safe handling precautions.
2.11 Identification
2.11.1 Physical Markings
IDNT-001
All components of the direct covariance flux instrument package shall be
marked indelibly on an exterior surface. Marking shall include:
 Manufacturer’s part number
 Unit serial number
 CGSN part number as defined below:
 P/N 3305-00004-00001
IDNT-002
The turbulent wind velocity sensor and the housing of the platform motion
sensors shall be labeled and have permanent marks to guide the correct
alignment of these sensors on the buoy tower.
2.12 Quality
2.12.1 Product Quality
QUAL-001
Instrument packages shall be manufactured in accordance with the
manufacturer’s best practices. Records of quality assurance tests and
inspections shall be available for review by the purchaser.
QUAL-002
A First Article Testing report shall be provided with each first article unit
delivered.
QUAL-003
A certificate of compliance shall be provided with each delivered unit.
The certificate of compliance shall be supported with copies of the
Factory Acceptance Test report and calibration records for each sensor
following integration into the unit.
QUAL-004
The materials used in construction of the instrument packages shall be
chosen and treated in such a way as to reduce the levels of wear,
corrosion and deterioration to allow multiple deployments of each unit.
3.0 Documentation and Support
N/A
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4.0 Appendices
4.1
Preferred OOI Standard Connector types.
Instruments should use an MCBH connector installed on the housing. The number of pins, and
pinout assignments, should be appropriate to the communication protocol of the instrument, and as
shown in the table below. This is an objective.
If the instrument is deployed below the surface, the underwater connector should be water blocked
so that there is a back-up o-ring seal in the event that the elastomeric sealing surface delaminates
from the metal shell. This is an objective.
(An example of a 6 pin water blocked connector is the MCBH(WB)-6-FS-Ti, manufactured by
Teledyne Impulse.)
Protocol
RS-232
RS-232
RS-485
(half duplex)
RS-485
(full duplex)
Pin #
4 Pin
6 Pin
6 Pin
8 Pin
1
Gnd
Pwr Gnd
Pwr Gnd
Data Gnd
2
RXD
RXD
Data B+
RD B+
3
TXD
TXD
Data ARD A4
12Vdc
12Vdc*
12Vdc*
Reserved
5
24Vdc*
24Vdc*
TD A6
Data Gnd
Data Gnd
TD B+
7
Pwr Gnd
8
+Vdc
9
10
* Only one voltage will be populated, depending on instrument input power needs.
Preferred vendors include:
Teledyne Impulse
9855 Carroll Canyon Road
San Diego, CA 92131
impulse@teledyne.com
SubConn, Inc.
www.subconn.com
mac-us@macartney.com
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