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Summary of Contents for Campbell Open Path Eddy Covariance System
- Page 1 Open Path Eddy Covariance System Operator’s Manual CSAT3, LI-7500, and KH20 9/06 C o p y r i g h t © 2 0 0 4 - 2 0 0 6 C a m p b e l l S c i e n t i f i c ,...
- Page 2 Warranty and Assistance The OPEN PATH EDDY COVARIANCE (OPEC) SYTEM is warranted by CAMPBELL SCIENTIFIC, INC. to be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless specified otherwise. Batteries have no warranty.
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Page 3: Table Of Contents
Open Path Eddy Covariance System Table of Contents PDF viewers note: These page numbers refer to the printed version of this document. Use the Adobe Acrobat® bookmarks tab for links to specific sections. 1. System Description .............1 1.1 OPEC (CSAT3 Only) ................1 1.2 Basic OPEC ....................1... - Page 4 25. List of Files Collected the First Time Using Two Cards ....... 31 26. List of Files Collected the Second time Using Two Cards ....31 27. Interpreter Settings to Read a Campbell Scientific, Inc. TOB1 Data File ....................34 28.
- Page 5 Open Path Eddy Covariance System Table of Contents 31. Default EdiRe Processing List Created by the Interpreter......36 32. Output File Location as Part of the Processing List .......37 33. Output File Location as Part of the Processing List .......37 34. Processing U and CO with 1 Chn Statistics Instruction......38...
- Page 6 Open Path Eddy Covariance System Table of Contents This is a blank page.
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Page 7: System Description
Open Path Eddy Covariance System This document will serve as a guide to properly install and operate a Campbell Scientific, Inc. Open Path Eddy Covariance System (OPEC). The OPEC is composed of various products, e.g. dataloggers, fast response turbulence sensors, slow response meteorological sensors, and software. -
Page 8: Additional Fast Response Sensors
(Campbell and Tanner, 1985 and Buck, 1976). The rate of scaling is a function of the atmospheric humidity. In high humidity environments, scaling can occur within a few hours. -
Page 9: Fetch And Sensor Height
Open Path Eddy Covariance System FIGURE 1. Eddy Covariance Sensors Mounted on a CM10 Tripod; the Datalogger Enclosure is on a Separate Tripod (not pictured) 2.1 Fetch and Sensor Height The eddy covariance sensors must be mounted at some height to ensure that the measurements are made within the local surface layer. -
Page 10: Mounting
Open Path Eddy Covariance System particularly between the eddy covariance sensors and the interface between the corn and soybean field. 2.2 Mounting The CSAT3, LI-7500, and HMP45C are mounted to a tripod or tower using a horizontal mounting arm, several Nu-Rail crossover fittings, and short lengths of pipe. -
Page 11: Side View Of The Csat3 And Li-7500 (Mounted Underneath Csat3)
Open Path Eddy Covariance System p/n 1017 0.75 inch by 0.75 inch crossover Nu-Rail fitting p/n 18048 0.75 inch diameter by 30.48 cm (12 inch) long aluminium pipe CM204 Crossarm with bracket, 1.3 m (4 ft) p/n 1049 1.0 inch by 0.75 inch crossover Nu-Rail fitting p/n 6332 0.75 inch diameter by 25.4... -
Page 12: Close Up View P/N 17716, Configured For Enc 10/12, Locking Mechanism
Open Path Eddy Covariance System FIGURE 4. CM110 Enclosure Mounting Hardware (p/n 17716 configured for ENC 10/12) Attached to the LI-7500 Electronics Box FIGURE 5. Close Up View p/n 17716, configured for ENC 10/12, Locking Mechanism... -
Page 13: Csat3 Electronics Box And P/N 17813 Enclosure Hanger Kit On Cm110 Tripod Body
Open Path Eddy Covariance System FIGURE 6. CSAT3 Electronics Box and p/n 17813 Enclosure Hanger Kit on CM110 Tripod Body FIGURE 7. CSAT3 and LI-7500 Electronics Boxes Mounted on the CM110 Tripod Body... -
Page 14: Enc12/14 Enclosure Mounted On The Cm110 Tripod Base
Open Path Eddy Covariance System FIGURE 8. ENC12/14 Enclosure Mounted on the CM110 Tripod Base FIGURE 9. HMP45C 10-plate Radiation Shield Mounted on the Body of the CM110 (left) and on the CM204 Horizontal Crossarm (right) -
Page 15: Measure Csat3 Azimuth
(prevailing wind) and record it into the station log book for later use. 2.3 Wiring A Campbell Scientific, Inc. eddy covariance system can take on several configurations and utilize several different dataloggers. It is impractical to document the different wiring schemes in this manual. However, do not despair;... -
Page 16: System Datalogger Program
Part number 18442 is a program for a basic system and p/n 18443 is a program for an extended system (with energy balance sensors). If your order did not include either p/n 18442 or 18443 as a line item on the order, contact Campbell Scientific, Inc. to purchase the appropriate datalogger program for your eddy... - Page 17 The datalogger programs align the measurements in time from the CSAT3, LI-7500, KH20, and FW05. The CSAT3 has a fixed two scan delay and LI-7500s shipped from Campbell Scientific, Inc. are programmed with a fixed 300 milliseconds (297.25 milliseconds) delay. These sensor delays are removed before the time series data is saved to Final Storage and before they are used to compute the online fluxes.
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Page 18: Generic Program Flowchart
Open Path Eddy Covariance System 3.1 Generic Program Flowchart Set default values for all variables: Scan every 0.1 or 0.05 seconds Measure Sensors: - datalogger panel temperature - FW05 - KH20 - CSAT3 - LI-7500 - HMP45C - battery voltage - Q7.1/NRLite/CNR1... -
Page 19: Program Configuration
Open Path Eddy Covariance System continuation of scan_count >= offset? TRUE FALSE Save the 4 most significant bits of the CSAT3 diagnostic word scan_count = scan_count+1 Flip the diagnostic bits in the LI-7500 diagnostic Compute LI-7500 AGC Convert LI-7500 diagnostic word into seperate warning flags... -
Page 20: Csat3 Azimuth
Open Path Eddy Covariance System 3.2.1 CSAT3 Azimuth The example programs report the wind direction in both the CSAT3 coordinate system (a right-handed coordinate system) and in the compass coordinate system (a screwball left-handed coordinate system). The CSAT3 coordinate system is relative to the CSAT3 itself and does not depend on the CSAT3’s orientation (azimuth of the negative x-axis). -
Page 21: Sensor Configuration
7. This address is set in software and can be changed using the LI-7500 PC support software and the LI-7500 serial cable and port. In addition to the SDM address, Campbell Scientific, Inc. sets the LI-7500 delay to 300 milliseconds (297.25 milliseconds). At a measurement rate of 10 Hz, this programmed delay is a 3 scan delay and at 20 Hz it is a 6 scan delay. -
Page 22: Loading A Program To The Datalogger
Open Path Eddy Covariance System CAUTION If you loan a CSAT3 or LI-7500 to a colleague, verify that the addresses are 3 and 7, respectively, before deploying the system into the field. 3.3 Loading a Program to the Datalogger Before the datalogger can begin to make measurements, a program must be transferred into its CPU. -
Page 23: System Operation
<Enter> key to execute the copy from the card to the CPU. To start the program, press the <Esc> key until the main menu appears and Campbell Scientific, Inc. logo appear in the upper left hand side. Press the <Enter> key, if necessary, select the “System Menu” and press the <Enter>... -
Page 24: Status Table
“Status” table includes, but is not limited to: OSVersion: Version and revision of the CRBasic datalogger operating system. As of the printing of this document, Campbell Scientific, Inc. recommends using, CR3000 OS v3.0, CR1000 OS v10.0, or CR5000 OS v2.1 or greater. -
Page 25: Data Retrieval
Data is saved on the PC/CF card as a binary file in a Campbell Scientific, Inc. format called Table Oriented Binary Format 3 (TOB3). TOB3 incorporates features to improve reliability of the card and allows for the accurate determination of each record’s time without the space required for individual... -
Page 26: Direct Connection Data Retrieval Via Loggernet
Open Path Eddy Covariance System practical if the PC will be located at the site and is continuously polling the datalogger because the volume of data is such that it takes about 8% to 25% of real time to download 10 Hz time series data. -
Page 27: Loggernet Station Setup For The "Flux" Table
Open Path Eddy Covariance System FIGURE 13. LoggerNet Station Setup for the “flux” Table FIGURE 14. LoggerNet Station Setup for the “ts_data” Table In the “Schedule” tab, configure the station’s data collection as shown in Figure 15. Modify the Primary Retry Interval, Number of Primary Retries, and the Secondary Retry interval as needed for the specific telecommunications option used at the station. -
Page 28: Loggernet Station Data Collection Schedule
Open Path Eddy Covariance System FIGURE 15. LoggerNet Station Data Collection Schedule To enable LoggerNet’s data collection, click on the Status Monitor button in the Toolbar. Select the station and click on the “Toggle On/Off” button. The time of the next data collection will appear in the “Next Data Call” column (see Figure 16). -
Page 29: File Management With Baler
“bale” it into a user specified file size (see Figures 17 and 18). Campbell Scientific, Inc. recommends using a one hour bale size for time series data that will be post processed by EdiRe and a 1 day bale size for the flux data. -
Page 30: Remote Data Retrieval Via A Pc/Cf Card
Open Path Eddy Covariance System FIGURE 18. Baler Station Setup for the “ts_data” Table 4.1.3 Remote Data Retrieval via a PC/CF Card To transfer data manually from the PC/CF card to the PC, remove the card from the datalogger following the proper card removal procedure (see the appropriate datalogger manual for details). -
Page 31: File Management With Cardconvert
Open Path Eddy Covariance System Never remove a PC/CF card from the datalogger or turn off CAUTION power to the datalogger without first shutting down the card. With a CR3000 or CR1000, press the “Removal Button” CFM100 Compact Flash/NL115 Ethernet/Compact Flash module. With a CR5000 select the PCCard|Remove Card menu. -
Page 32: File Format Flow
Open Path Eddy Covariance System TOB1 Binary File TOB3 File from PC/CF Card TOA5 Array ASCII file Compatible with header ASCI Arrays without header FIGURE 19. File Format Flow Start the CardConvert utility. When CardConvert is started, a summary of its current settings is displayed in the lower right hand screen. -
Page 33: Destination File Option Screen
Open Path Eddy Covariance System FIGURE 20. Destination File Option Screen To create an EdiRe raw format file list using the Interpreter, save the data in the TOB1 file format. If another format is needed at a later date, convert the TOB1 files into the other file format (see Figure 19). -
Page 34: Fully Configured Cardconvert Start Up Screen
Open Path Eddy Covariance System FIGURE 21. Fully Configured CardConvert Start Up Screen The converted files will look something like the 20 Hz files shown in Figure 22. Each file name with consist of a user specified file name and the time stamp of the first record in each file with a one minute resolution. -
Page 35: Collecting Data With One Card
Open Path Eddy Covariance System 4.1.4.1 Collecting Data with One Card If a single card is used to collect the data and the data on the card is not deleted after copying it to the PC, the datalogger will append the data collected since the card was removed to the data file on the card. -
Page 36: Collecting Data With Two Cards
Open Path Eddy Covariance System FIGURE 24. List of Files Where the Duplicate Files are Renamed to *.bak 4.1.4.2 Collecting Data with Two Cards Data can be collected using two cards. The card in the datalogger is removed and replaced with an empty one. The data from the original card is copied to the computer at some later time. -
Page 37: Data Processing
Open Path Eddy Covariance System FIGURE 25. List of Files Collected the First Time Using Two Cards FIGURE 26. List of Files Collected the Second Time Using Two Cards 4.2 Data Processing There are several ways to process the raw time series data collected by the system. -
Page 38: Online Processing
4.2.2 Off-line Processing with EdiRe EdiRe is a powerful and flexible software package for processing eddy covariance data collected by a Campbell Scientific, Inc. system. Best of all, it is available at no charge from the University of Edinburgh’s ftp site (http://www.geos.ed.ac.uk/abs/research/micromet/EdiRe/Downloads.html). -
Page 39: Creating Raw File Format And Processing Lists
Along with the information on the University of Edinburgh’s ftp site, see the EdiRe online help and the Campbell Scientific, Inc. Application Note on using EdiRe. EdiRe lends itself to experimentation. The best way to learn how to use EdiRe is to experiment with it. -
Page 40: Interpreter Settings To Read A Campbell Scientific, Inc. Tob1 Data File
Open Path Eddy Covariance System FIGURE 27. Interpreter Settings to Read a Campbell Scientific, Inc. TOB1 Data File FIGURE 28. Folder that Contains the Raw TOB1 Time Series Data Files... -
Page 41: Example Edire Raw File Format And Processing Lists
Open Path Eddy Covariance System FIGURE 29. Competed Interpreter Screen FIGURE 30. Estimated Sample Frequency and Correct Sample Frequency 4.2.2.2 Example EdiRe Raw File Format and Processing Lists To view the Lists in EdiRe, select the Processing|Options menu. The “Raw File Format”... -
Page 42: Default Edire Processing List Created By The Interpreter
“Output Files” tab or as part of the processing list with the “Location Output Files” instruction (Figure 32). Campbell Scientific, Inc. recommends incorporating the output file destination as part of the processing list rather than changing the output file name in the “Output File” tab. This will prevent the accidental merger of results from multiple stations. -
Page 43: Output File Location As Part Of The Processing List
Open Path Eddy Covariance System FIGURE 32. Output File Location as Part of the Processing List FIGURE 33. Output File Location as Part of the Processing List... -
Page 44: Computing Co
Open Path Eddy Covariance System FIGURE 34. Processing U and CO with 1 Chn Statistics Instruction FIGURE 35. Computing CO Flux with 2 Chn Statistics and Graphing U Statistic with Plot Value Instruction... -
Page 45: Eddy Covariance Theory 101
Open Path Eddy Covariance System 5. Eddy Covariance Theory 101 FIGURE 36. Ideal Vertical Profiles of Virtual Potential Temperature and Specific Humidity Depicting All the Layers of the Atmospheric Boundary Layer. The surface layer (Figure 36) is comprised of approximately the lower 10% of the atmospheric boundary layer (ABL). - Page 46 Open Path Eddy Covariance System ρ′ where F is the carbon dioxide flux, is the instantaneous deviation of the U ′ is the instantaneous deviation of carbon dioxide density from the mean, vertical wind speed from the mean, LE is the latent heat flux, L is the latent ρ′...
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Page 47: Csat3 Orientation
Appendix A. CSAT3 Orientation A.1 Determining True North and Sensor Orientation The orientation of the CSAT3 negative x-axis is found by reading a magnetic compass and applying the site-specific correction for magnetic declination; where the magnetic declination is the number of degrees between True North and Magnetic North. -
Page 48: A-2. A Declination Angle East Of True North (Positive) Is Subtracted From 360 (0) Degrees To Find True North
Appendix A. Sensor Orientation Declination angles are always subtracted from the compass reading to find True North. A declination angle East of True North is reported as positive a value and is subtracted from 360 (0) degrees to find True North as shown Figure A-2. -
Page 49: Online Magnetic Declination Calculator
Appendix A. Sensor Orientation A.2 Online Magnetic Declination Calculator The magnetic declination calculator web calculator published by NOAA’s Geophysical Data Center is available at the following url http://www.ngdc.noaa.gov/seg/geomag/jsp/struts/calcDeclination. After the web page loads, enter the site zip code, or longitude and latitude, then click on the “Compute Declination”... - Page 50 Appendix A. Sensor Orientation This is a blank page.
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Page 51: Sensible Heat Flux Without A Fw05
Appendix B. Sensible Heat Flux without a FW05 B.1 Speed of Sound and Sonic Temperature In the following section the speed of sound will be expressed as a sonically measured temperature. The effects of humidity, on the speed of sound, will be combined into this temperature. -
Page 52: Sonic Temperature, Temperature, And Humidity
Appendix B. Sensible Heat Flux without a FW05 1 0 84 1 0 61 (B-6) 1 0 94 Expand and collect terms. 1 145 0 5124 (B-7) 1 0 94 − 1 0 94 Multiply the above by and ignore the second and third order −... -
Page 53: Sensible Heat And Specific Humidity Flux
Appendix B. Sensible Heat Flux without a FW05 Expand Equation (B-14). + ′ = ′ + ′ + ′ + ′ ′ 0 51 0 51 0 51 0 51 (B-15) B.3 Sensible Heat and Specific Humidity Flux In the following section write the sonic sensible heat flux as a function of sensible and latent heat flux. -
Page 54: B.4 Sensible And Latent Heat Flux
Appendix B. Sensible Heat Flux without a FW05 ′ ′ = ′ ′ + ′ ′ + ′ ′ 0 51 q w T 0 51 T w q (B-23) = ′ ′ + ′ ′ 1 0 51 0 51 T w q Multiply the first term on the right hand side by and recall that... - Page 55 Appendix B. Sensible Heat Flux without a FW05 ρ Multiply Equation (B-28) by and the second term on the right hand side by = 2.45 × 10 @ 20 ° C). . Where L is the latent heat of vaporization (L J kg 0 51 ρ...
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Page 57: Appendix C. References
Buck, A. L.: 1976, “The Variable-Path Lyman-Alpha Hygrometer and its Operating Characteristics”, Bull. Amer. Meteorol. Soc., 57, 1113-1118. Campbell, G. S., and Tanner, B. D.: 1985, “A Krypton Hygrometer for Measurement of Atmospheric Water Vapor Concentration” Moisture and Humidity, ISA, Research Triangle Park, North Carolina. - Page 58 Appendix C. References Tanner, C. B. and Thurtell, G. W.: 1969, Anemoclinometer measurements of Reynolds stress and heat transport in the atmospheric surface layer, Final Report, United States Army Electronics Command, Atmospheric Sciences Laboratory, Fort Huachuca, Arizona. Tanner, B. D.: 1988, “Use Requirements for Bowen Ratio and Eddy Correlation Determination of Evapotranspiration”, Proceedings of the 1988 Specialty Conference of the Irrigation and Drainage Division, ASCE, Lincoln, Nebraska, 19-21 July 1988.
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- Page 60 Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za cleroux@csafrica.co.za Campbell Scientific Australia Pty. Ltd. (CSA)
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