ASD Document 600540 Rev. J
66
FieldSpec® 3 User Manual
www.asdi.com
Chapter 7 Field Measurements
other than the one of interest should be minimized in the selected targets. This
is achieved by carefully controlling viewing and illumination geometry, often
in a laboratory. This type of study is often performed as a feasibility study
prior to a full study evolving collection of spectra of background material.
7.9.3
Viewing Geometry
The selection of an appropriate viewing geometry depends upon whether the
spectra are used for image analysis or for a feasibility study.
Image analysis:
a viewing geometry similar to the airborne sensor is
required.
Feasibility study:
it is possible to eliminate much of the confounding
variance typically present in an image data set by fixing the viewing and
illumination geometry.
For vegetation, spectra can be acquired at the spatial scale of the leaf/needle,
branch, or canopy. Canopy level spectra are most suitable for image analysis
and interpretation. Rarely can leaf/needle or branch level spectra be used
directly to interpret an image. Leaf/needle and branch level spectra are useful
to understand how the canopy level spectra are influenced by changes in
leaf/needle and branch spectral changes as opposed to changes in the canopy
structure.
7.10 Suggested Set-up
7.10.1 RS3 Application
Step 1
Follow the instructions for plugging in the instrument and starting the RS
3
software.
Step 2
Attach any required foreoptic accessories.
Step 3
Open the pull down menu
Control -> Adjust Configuration [Alt+C,C]
in
the RS
3
application.
Step 4
Set the white reference number of scans to 30, and dark current averages to 60
scans.
Note:
The actual spectrum average will be determined by striking a compromise
between noise reduction through averaging the spectra and the time desired
for each spectrum collection. For instance, if you are using the instrument in
the field, are walking a large area, and are making frequent spectral readings,
you will want a shorter average setting than if you are collecting spectra
in-situ and desire the cleanest spectra possible.
Step 5
Optimize
the instrument to the Spectralon.
Summary of Contents for FieldSpec 3
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Page 10: ...ASD Document 600540 Rev J x FieldSpec 3 User Manual www asdi com Notes...
Page 50: ...ASD Document 600540 Rev J 40 FieldSpec 3 User Manual www asdi com Chapter 5 Batteries Notes...
Page 90: ...ASD Document 600540 Rev J 80 FieldSpec 3 User Manual www asdi com Appendix A Troubleshooting...
