Sequoia LISST-200X, Руководство пользователя

Страница: 56 / 112

LISST-200X Operation Details 48 LISST-
200X User’s Manual
11.
Data Quality Control
Making sure your data make sense.
STEP ACTION RESULT
1
•
Follow steps 1-5 in the previous section: View
Processed Data File
Data file loaded
2
3
•
The first value to inspect is the Optical
Transmission. By definition, transmission must be a
number between 0 and 1 (except that electronic
noise may cause it to be slightly higher than 1 in
particle-free water)
•
Tip: The transmission value is in column 60 of the
.CSV file.
•
If transmission shows up as being larger than 1
(one), then your measurement is most likely taken
in very clear water and/or you have a bad
background measurement obtained with dirty water
and/or dirty windows.
•
If your background measurement was obtained
using dirty water, it may be possible to redo the
background using clean water and re-process the
data, then check to see if the transmission values
drop below 1 (one).
Transmission values
much greater than 1 or
less than 0 indicate
bad data.
4
•
If your transmission values generally are in the
0.98-0.995 range, your measurements are taken in
very clear water.
•
This means that the signal-to-noise ratio will be low,
and the data may have a lot of noise in them, but
can most likely still be used.
Transmission values
very close to 1 yield
noisy data.