Campbell Open Path Eddy Covariance System, Instruction Manual

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 I n c...

Page 2: ...all other warranties expressed or implied including warranties of merchantability or fitness for a particular purpose CAMPBELL SCIENTIFIC INC is not liable for special indirect incidental or consequen...

Page 3: ...muth 14 3 2 2 Sensor Configuration 15 3 3 Loading a Program to the Datalogger 16 3 3 1 Direct Connection via LoggerNet 16 3 3 2 Remote via PC CF Card 16 3 4 System Operation 17 3 4 1 Monitoring Data 1...

Page 4: ...nted on the Body of the CM110 and on the CM204 Horizontal Crossarm 8 10 Terminal Strip Adapters for Power Connection to External Battery 10 11 CSAT3 Right Hand Coordinate System Horizontal Wind Vector...

Page 5: ...ty Depicting All the Layers o the Atmospheric Boundary Layer 39 A 1 Magnetic Declination for the Conterminous United States 2004 A 1 A 2 A Declination Angle East of True North Positive is Subtracted f...

Page 6: ...Open Path Eddy Covariance System Table of Contents iv This is a blank page...

Page 7: ...Horizontal wind speed and direction are computed by the datalogger from the three dimensional measurements of wind made by the sonic anemometer 1 1 OPEC CSAT3 Only The minimum components required for...

Page 8: ...small Thus water vapor fluctuation measurements can still be made with the hygrometer The effects of the scaling can be easily reversed by wiping the windows with a moist swab To measure other trace g...

Page 9: ...tal distance traveled ratio of 1 100 may be used as an absolute bare minimum rough rule of thumb for determining the measurement height The following references discuss fetch requirements in detail Br...

Page 10: ...istortions Tilt the IRGA sensor head about 60 degrees from horizontal to minimize the amount of precipitation that accumulates on the windows The LI 7500 is attached to the CM204 horizontal mounting a...

Page 11: ...0 48 cm 12 inch long aluminium pipe p n 6332 0 75 inch diameter by 25 4 cm 10 inch long aluminium pipe p n 1049 1 0 inch by 0 75 inch crossover Nu Rail fitting p n 1017 0 75 inch by 0 75 inch crossove...

Page 12: ...Covariance System 6 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 Loc...

Page 13: ...Open Path Eddy Covariance System 7 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: ...Eddy Covariance System 8 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 Cross...

Page 15: ...nd detailed wiring diagram See the datalogger program for wiring instructions 2 4 Power The system requires about 1 5 to 14 W continuous power depending on the datalogger and sensor configuration The...

Page 16: ...positive post and the other the negative post Figure 10 FIGURE 10 Terminal Strip Adapters for Power Connection to External Battery Power connections are listed in the programs p n 18442 or 18443 Be s...

Page 17: ...lay 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 Fin...

Page 18: ...ta from molar density to molar fraction Convert LI 7500 data from molar density to mass density Convert CSAT3 data for WindVector wind_east Uy wind_north Ux Load the FW05 data from OFFSET 0 scans back...

Page 19: ...f LI 7500 warning TRUE disable_flag_on 4 warning flags Disable count of LI 7500 TRUE LI 7500 CO2 NAN or SDM error FALSE disable_flag_on 2 FALSE Enable covariance processing TRUE disable_flag_on 2 proc...

Page 20: ...ts to the North As described in Section 2 and 2 2 1 orient the CSAT3 so that it is pointing into the prevailing wind direction If you have done so the CSAT3 negative x axis will point into the prevail...

Page 21: ...m Campbell Scientific Inc is set with an SDM address of 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...

Page 22: ...Windows XP computer is unavailable the 16 bit File Allocation Table FAT is also supported with the above CRBasic dataloggers To avoid potential problems mixed data and connectivity issues configure L...

Page 23: ...ampbell Scientific Inc logo appear in the upper left hand side Press the Enter key if necessary select the System Menu and press the Enter key Select the Run Stop Program menu and press the Enter key...

Page 24: ...Measurement tasks are resynchronized The resynchronization results in a number of SkippedScan equal to the buffer depth DataFillDays The number of days to fill a table in both the CPU and CRD memory T...

Page 25: ...ing similar to that used in Microsoft Excel In the Array Compatible CSV time is reported as elements of the array e g in the same format as the Campbell Scientific Inc mixed array dataloggers Campbell...

Page 26: ...ill meet the data file management needs as long as it can find and replace text within a file name 4 1 1 Direct Connection Data Retrieval via LoggerNet LoggerNet can be used to automatically collect a...

Page 27: ...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 F...

Page 28: ...e 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 To display additional station information...

Page 29: ...data that will be post processed by EdiRe and a 1 day bale size for the flux data To run more than one instance of the Baler use the WorkDir pathname switch and two shortcuts one for the time series d...

Page 30: ...collect and save the data in the CPU When the card is returned to the datalogger the data will be transferred automatically from the CPU to the card When a card is inserted into a CRBasic datalogger t...

Page 31: ...and replace it with a fresh one This method is fast and does not require a PC at the site The disadvantage of this approach is that it will create non uniform file sizes around the time that the card...

Page 32: ...File name must be changed Click on the Select Card Drive button and navigate to the temporary directory that contains the raw time series and flux data files Select the drive and click on the OK butto...

Page 33: ...om the card and processing it with your off line tools Only through this type of experimentation will you determine the file sizes that work best for you Finally change the output file name The defaul...

Page 34: ...les 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 Note that the first file and last file...

Page 35: ...ubsequent time rename the last partial file from _0700 dat to _0700_1 dat This will ensure that the complete version of this file is saved to the folder CardConvert will not overwrite existing files w...

Page 36: ...ent method of collecting data Only new data is collected however two partial files within a baling period are created Variable file lengths are not an issue with EdiRe but maybe for some other post pr...

Page 37: ...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 Some of these are considered standard by the...

Page 38: ...moments required for an off line coordinate rotation following Kaimal and Finnigan 1994 and Tanner and Thurtell 1969 The datalogger programs do not apply a coordinate rotation to the data 4 2 2 Off li...

Page 39: ...t with it EdiRe is not a Campbell Scientific Inc product Campbell Scientific Inc provides limited support of EdiRe specifically in reading in TOB1 data files If further support is required contact the...

Page 40: ...Open Path Eddy Covariance System 34 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: ...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 li...

Page 42: ...orating 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 sta...

Page 43: ...Open Path Eddy Covariance System 37 FIGURE 32 Output File Location as Part of the Processing List FIGURE 33 Output File Location as Part of the Processing List...

Page 44: ...n Path Eddy Covariance System 38 FIGURE 34 Processing Uz and CO2 with 1 Chn Statistics Instruction FIGURE 35 Computing CO2 Flux with 2 Chn Statistics and Graphing Uz Statistic with Plot Value Instruct...

Page 45: ...y layer ABL The fluxes of water vapor and heat within this layer are nearly constant with height when the following criteria are met the surface has approximate horizontal homogeneity and the relation...

Page 46: ...are computed online by the CRBasic datalogger as are the cross products second order moments required to apply a post processing coordinate rotation following Kaimal and Finnigan 1994 and Tanner and T...

Page 47: ...c declination where the magnetic declination is the number of degrees between True North and Magnetic North Magnetic declination for a specific site can be obtained from a USGS map local airport or th...

Page 48: ...shown in Figure A 3 Note that when a negative number is subtracted from a positive number the resulting arithmetic operation is addition For example the declination for Longmont CO 10 June 2006 is 9...

Page 49: ...the web page loads enter the site zip code or longitude and latitude then click on the Compute Declination button Figure A 4 FIGURE A 4 Online Magnetic Declination Calculator with Inputs and Output fo...

Page 50: ...Appendix A Sensor Orientation A 4 This is a blank page...

Page 51: ...pecific heats of moist air The specific heats of moist air can be written as C qC q C C q p p p p w d d 1 1 0 84 B 2 C qC q C C q v v v v w d d 1 1 0 94 B 3 where q is the specific humidity of air the...

Page 52: ...ure and Humidity In the following section define T q Ts and w in terms of an instantaneous value a mean and a deviation from the mean where w is the vertical wind in the natural wind coordinates Recal...

Page 53: ...0 51 0 51 0 51 0 51 0 51 0 51 0 51 0 B 18 Note that the following are true w T w T q w T w T q s 1 0 51 0 51 B 19 w T wT w T s s s B 20 Substitute Equations B 18 and B 19 into B 20 w T w T w T q w T q...

Page 54: ...M e v d v v d v v d v v d d v B 25 where mv is the mass of the water vapor in the air md is the mass of the dry air v is the density of the water vapor in the air d is the density of the dry air Mv i...

Page 55: ...n B 29 for latent heat flux LE PL R T w T w T T T v d s s 0 51 2 B 30 Assume that the system is not using a FW05 to measure temperature fluctuations Find the calculated sensible heat flux Hc by solvin...

Page 56: ...Appendix B Sensible Heat Flux without a FW05 B 6 This is a blank page...

Page 57: ...J J 1994 Atmospheric Boundary Layer Flows Their Structure and Measurement Oxford University Press New York 289 pages Kaimal J C and J E Gaynor 1991 Another look at sonic thermometry Bound Layer Meteor...

Page 58: ...f Evapotranspiration Proceedings of the 1988 Specialty Conference of the Irrigation and Drainage Division ASCE Lincoln Nebraska 19 21 July 1988 Wallace J M and P V Hobbs 1977 Atmospheric Science An In...

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Page 60: ...campbellsci com br suporte campbellsci com br Campbell Scientific Canada Corp CSC 11564 149th Street NW Edmonton Alberta T5M 1W7 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientif...