Delta Electronics SS1-UM-1.05 user manual Relationship between Mean Leaf Angle and Eladp

Page 45

Estimating ELADP in the field

If the canopy shows a clear predominance of horizontal or vertical leaves, then choose a small volume of the canopy that is representative. Count the number of leaves that are at more than 45° from the vertical (i.e. mostly horizontal), and the number of leaves that are less than 45° from the vertical. If the leaves are curved, pick the angle at the widest part of the leaf. The ELADP can be estimated as the number of horizontal leaves (Nh) divided by the number of vertical leaves (Nv), multiplied by π /2 (1.6).

ELADP = π N h 2 N v

The factor π /2 comes from the fact that the vertical leaves are distributed about the vertical axis, so for any light ray, some will be seen face-on, and some edge-on. In effect, the ellipsoidal distribution is being further approximated as a cylindrical distribution.

If you set ELADP to 1024, and Absorption to 1.0, the LAI calculations will be equivalent to the simple Beer’s law inversion based on black, horizontal leaves.

Relationship between Mean Leaf Angle and ELADP

Wang & Jarvis (1988) describe the relationship between ELADP and the Mean Leaf Angle, which is sometimes known from other studies. Their results are summarised by the following graph:

 

90

 

 

 

 

 

80

 

 

 

 

 

70

 

 

 

 

 

60

 

 

 

 

degrees

50

 

 

 

 

 

 

 

 

 

MLA

40

 

 

 

 

 

 

 

 

 

 

30

 

 

 

 

 

20

 

 

 

 

 

10

 

 

 

 

 

0

0.1

1

10

100

 

0.01

 

 

 

ELADP

 

 

SunScan User Manual v 1.05

Measurement options • 45

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Contents SS1-UM-1.05 SunScanAcknowledgements CopyrightTrademarks CE conformityContents Measurement options Menus and Screens More Psion and file handling notesLAI theory Technical Reference sectionIndex AppendicesIntroduction How to use the manualsSunScan Canopy Analysis System Organisation of this manualSunScan probe Field accessoriesBeam Fraction sensor Data Collection TerminalGetting Started Preliminary checksWorkabout and SunScan probe Checking the Workabout hardware Installing the s/w Installing the SunData s/w in your PCSunData s/w Diskette What the s/w doesRunning SunData Setting up your PCs COM portCommunication checks SunScan probe to PCWorkabout to PC Running SunData in Windows SunScan Tutorial About this tutorialWorking with the Workabout Starting SunData in the Workabout What to do if you get lostStarting the PC software Using a PC instead of the WorkaboutThis page is intentionally blank Working through the menu options Setting up a measurement sessionHot Keys File SavingTaking readings Using the Emulator modeWithout a Beam Fraction Sensor Connecting the SunScan probeConnecting the Beam Fraction Sensor Measuring Leaf Area Index without a Beam Fraction Sensor Averages Reviewing your data fileTransferring the data file to your PC From the WorkaboutTo the PC Initiating the file transfer from the Workabout Meanwhile, on the PC Conclusion of the Tutorial RS232 communication problemsSunData Screens on the Workabout Settings Menus and ScreensFile Utils ContdQuit Navigating Psion directories and screens More Psion and file handling notesWorkabout User Guide Navigating the Psion directories and screensPsion subdirectory usage in file select dialogs Re-installing the SunData application icon Deleting unwanted Workabout filesFlashcards reformatting Configuration and data file handling SunData Configuration filesData memory management Creating a configuration file Default .cfgRestoring a configuration Data filesDisplaying data files on your PC .PRN file.CSV file Data file layouts and data groups Page Measurement options Experiment designAbove-canopy reference requirements Canopy Sampling volume Canopy type and BFS practicalitiesCanopy type and LAI estimates Planning for the sun’s position Preferred light and weather conditionsAdvice on Absorption and Eladp values Setting EladpAbsorption Estimating Eladp in the field Relationship between Mean Leaf Angle and EladpWorkabout setup SunScan System Measurement modesLAI, PAR and All displays Autolog function Probe handling in the field Measurement procedures in the fieldProbe GO button Levelling the probeBFS handling in the field Using the tripodUse of the tripod WorkaboutFinding North, and setting the shade ring Levelling the BFSExtension cables, and the location of the BFS Factory light calibration PAR calibrationsChecking the probe/BFS matching Recalibrate optionRestoring the factory calibration Routine maintenance and cleaningEffect of the shade ring on the BFS Comparing the calibration with other PAR sensorsSunScan probe and Beam Fraction Sensor Environmental and moisture protectionIngredients of the LAI computation method LAI theoryDerivation of Wood’s SunScan canopy analysis equations Major assumptionsTheory versus reality Beers law for canopy absorption Campbells Ellipsoidal LAD equationsTransmission of Diffuse Light Transmission fraction τ Is given by I/I0 Diffuse light transmission cosine corrected sensor Modelling the canopy transmissionDetail Accuracy of LAI calculations Functions used to model canopy transmissionDiffuse light cosine response sensor Diffuse light hemispherical response sensorExp 0.1 . x . atan 0.9 Atan L Q Spher Modelling incomplete PAR absorption and scatteringScientific references Calculating zenith anglesSummary Jones, Hamlyn G Plants and Microclimate second edition. CUP Technical Reference section Maintenance and repairChecking the batteries SunScan probe batteriesChecking the desiccant Re-setting the factory calibration Checking the PAR calibrationFactory calibration method Problems running the SunData application TroubleshootingPsion Workabout While running SunDataInsufficient power to write data reported Technical Support SunScan Probe Type SS1 SpecificationsBeam Fraction Sensor type BF1 Data Collection Terminal type DCT1 Psion WorkaboutTelescopic Tripod type BFT1 Carrying Case type SCC1Spares Kit type SPS1 Logging CablesSpectral response PAR PerformanceSunScan system cosine response Cosine responses of probe and BFSLogging the probe as a Linear Quantum Sensor AppendicesLogging the Beam Fraction sensor SunData PC s/w Upgrading the SunScan systemWorkabout SunData s/w Revision HistoryChoice of different programs File transfer between Workabout and PCPsiWin Workabout Remote LinkSlink and Rcom Example using SlinkDrives on the PC are referred to as REMA, Remc REM = remote Documentation of Rcom and Slink Example using RcomAlternative file transfer mechanisms Using the Workabout Comms applicationSending a file to a Communication program Sending a file to a serial printerGlossary Page Accuracy IndexIndex Field use 39, 46, 48, 50, 51, 58

SS1-UM-1.05 specifications

Delta Electronics has long been recognized for its innovative solutions in power and thermal management technologies. One of its notable products is the SS1-UM-1.05, a compact and efficient power supply module designed to meet the needs of a variety of applications, from industrial automation to telecommunications.

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The SS1-UM-1.05 also boasts a compact footprint, which is essential for space-constrained installations. Its design emphasizes not only performance but also ease of integration into existing systems. The module provides multiple output voltage options, allowing it to cater to specific power requirements, whether it be for industrial machinery or consumer electronics.

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The SS1-UM-1.05 is also designed with a robust enclosure that adheres to stringent safety and environmental standards. This enhances its durability and reliability, ensuring it can withstand harsh operating conditions. With these features, Delta Electronics demonstrates its commitment to delivering high-quality products that meet the evolving needs of industries worldwide.

Overall, the Delta SS1-UM-1.05 power supply module is an exemplary solution for those seeking a reliable, efficient, and compact power source. Its advanced features and technologies make it an indispensable component in modern electronic systems.
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