User manual

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• Document code: SS1-UM-1.05
Menus and Screens ..................................................................................30
More Psion and file handling notes.........................................................33
Navigating Psion directories and screens...............................................33
The Workabout User Guide ........................................................................ 33
Navigating the Psion directories and screens............................................. 33
Psion subdirectory usage in file select dialogs ........................................... 34
Re-installing the SunData application icon.................................................. 35
Deleting unwanted Workabout files ............................................................ 35
Flashcards - reformatting............................................................................ 35
Data memory management .......................................................................36
Configuration and data file handling........................................................36
SunData Configuration files ........................................................................ 36
Data files ..................................................................................................... 37
Displaying data files on your PC ..............................................................38
The .PRN file............................................................................................... 38
The .CSV file............................................................................................... 38
Data file layouts and data groups ............................................................... 39
Measurement options...............................................................................41
Experiment design.....................................................................................41
Above-canopy reference requirements....................................................... 41
Canopy type and BFS practicalities............................................................ 42
Canopy type and LAI estimates .................................................................. 42
Canopy Sampling volume ........................................................................... 42
Preferred light and weather conditions .......................................................43
Planning for the sun’s position .................................................................... 43
Advice on Absorption and ELADP values ...............................................44
Absorption................................................................................................... 44
ELADP ........................................................................................................ 44
Relationship between Mean Leaf Angle and ELADP.................................. 45
SunScan System Measurement modes....................................................46
Workabout setup......................................................................................... 46
The Autolog function ................................................................................... 47
Measurement procedures in the field.......................................................48
Probe handling in the field........................................................................... 48
BFS handling in the field ............................................................................. 49
PAR calibrations ......................................................................................... 51
Environmental and moisture protection ...................................................... 53
LAI theory...................................................................................................54
Ingredients of the LAI computation method............................................54
Derivation of Wood’s SunScan canopy analysis equations...................55
The major assumptions............................................................................... 55
Beer's law for canopy absorption................................................................ 56
Campbell's Ellipsoidal LAD equations......................................................... 56
Transmission of Diffuse Light...................................................................... 56
Modelling the canopy transmission............................................................. 58
Accuracy of LAI calculations....................................................................... 60
Functions used to model canopy transmission ......................................60
Diffuse light - cosine response sensor........................................................ 60
Diffuse light - hemispherical response sensor. ........................................... 60
Modelling incomplete PAR absorption and scattering................................. 61
Calculating zenith angles ............................................................................ 62
Summary..................................................................................................... 62
Scientific references..................................................................................62
Technical Reference section....................................................................64