Open Path Eddy Covariance Training (OPEC)
The
Open path Eddy Covariance Training (OPEC) class covers the proper use
of Campbell Scientific equipment in eddy covariance measurements. This
course does not cover micrometerology theory. Basic theory and
assumptions used will be noted with respect to proper use and
installation of eddy covariance systems. It is recommended that
micrometerology related classes at a university or graduate level be
completed prior to registration for this class.
The training
course is taught by Campbell Scientific Applications Engineers. Class
size is limited to ensure personalized instruction and assistance.
"Hands-on" programming exercises and course handouts are used to
reinforce the concepts covered by the instructors.
Course fees include a Training Manual and the use of a datalogger, computer, and sensors. Lunch will be provided all course days, and there will be a tour of Campbell Scientific's facilities. A brief course outline is listed below:
1. Theoretical considerations
Definition of flux and main assumptions of eddy covariance technique
Sensible heat ( H ), latent heat ( LE ), and CO2 ( cF ) flux definitions
Definition of energy balance –what are the main components, what is energy balance closure
2. System description and components
Basic OPEC system – sensors included
Extended OPEC System – additional sensors needed to close energy balance
Additional fast response sensors
3. Installation of OPEC System
Fetch and station position –measurement field size requirements, position of EC station, sensors
heights
Setting up a tripod
CSAT3 mounting: orientation, leveling, cable connections
LI7500 mounting: control box, sensor head, fuse check
Enclosure mounting
Energy Balance sensors: net radiometer, soil heat flux plates, soil temperature probe, soil moisture
probes
Datalogger configuration and program downloading using a laptop
4. Introduction to programming with
CRBasic
CR1000 Hardware
CR1000 Specifications
CR1000 Memory
Short Cut Program Generator
LoggerNet
Introduction to Programming with CRBasic
CRBasic Editor
Template
Data Types and Formats
Instruction Parameters
Programming for Control
On-line help
Automated Data Collection
File Control, Operating Systems and Transformer
Typical CR1000 Program
5. OPEC Programming
What is measured
What is processed
What is saved as data
Output format with units for both, time-series and mean values
User entered variables for OPEC if needed
Measurement section
Where to add auxiliary sensor measurements
Mean processing of auxiliary variables
Sensor Configuration
Loading a program to datalogger
Direct connect with Loggernet
Remote connect with PC/CF card
System Operation
Monitoring data – Status Table
6. SDM Connections
Timing diagram of the 3 lines.
CSAT3 has a two scan delay at any sample rate.
The LI-7500 has a 300 mSec delay, three scans at 10 Hz and six scans at 20 Hz
SDM lead length limitations – data from CSAT3 and LI7500 combined
SDM-HUB – reducing total SDM lead length
SDM Datalogger instructions to slow SDM baud rate
CRBasic SDM bit period search programs
7. CSAT3 – Three Dimensional Sonic
Anemometer
Initial setup – factory settings, SDM address
Operational principles – digital signal processing, ultrasonic signal
CSAT3 trigger - CSAT3 SDM instruction and parameters in configuring the CSAT3
CSAT3 diagnostics byte
CSAT32 software
Criteria used for discarding measurement from on-line processing
Zero offset check
8. CS7500 (LI7500)
Initial setup - Campbell Scientific, Inc. factory default settings, SDM address, bandwidth, delay
(297.25 mSec or ~ 300 mSec).
Theory of operation – measuring absorptance, relating absorptance to concentration, cross
sensitivity, zero drift, basic equations
LI7500 SDM instruction and parameters in configuring the LI7500
LI7500 Software
LI7500 diagnostic byte
Criteria used for discarding measurement from online processing
Zero and span LI7500
9. Site Maintenance
CSAT3
Check the status and position of the wicks
Check the surface conditions of the transducers, and clean them, if necessary
Check the junction and clean it, if using FW05
CS7500
Check the condition of the sapphire window, and clean, if necessary
Zero and Span
Enclosure
Check the condition inside the enclosure for condensation, and replace the desiccant bags, if
necessary
Any others
10. Data Retrieval and Management
Direct connection and data retrieval via Loggernet
Data collection with a PC is only practical if the PC is located on-site with a direct connect
interface (Free-wave radio, NL115 or NL100). The PC can not be used to "milk" data.
File management with Baler
Remote data retrieval via PC or Compact Flash Card
Discussion on Industrial Grade SLC CF cards vs. Commercial MLC CF cards
11. Data Processing
File management with CardConvert – format options, converting CSI formats
Brief discussion on CSI File Formats: TOB1, TOB3, TOACI1, TOA5
Online Processing
Off-line Processing with EdiRe
How to get EdiRe – website information
Use of EDIRE's Interpreter to create custom Raw File Format List and Default
Processing List
Basic Data Processing
Location Output Files
Extract
User Defined Fast
Raw Subset (filtering based on CSAT3 and LI7500 diagnostic flags)
1 chn statistics (covariance)
2 chn statistics (standard deviation and mean)
Wind speed and direction (CSAT3 and compass coordinates)
Webb correction
Plot Value
NaN and INF test