Campbell CR800 Series - Displaying Data: Custom Menus - Details

Section 7. Installation
207
Equating the two expressions for Cos (θ') and using the previous equation for s
i
;
Solving for (Θ
i
')
2
, one obtains;
Summing (Θ
i
')
2
over N samples and dividing by N yields the variance of Θu.
Note The sum of the last term equals 0.
The term,
is 0 if the deviations in speed are not correlated with the deviation in direction.
This assumption has been verified in tests on wind data by Campbell Scientific;
the Air Resources Laboratory, NOAA, Idaho Falls, ID; and MERDI, Butte, MT.
In these tests, the maximum differences in
and
have never been greater than a few degrees.
The final form is arrived at by converting from radians to degrees (57.296
degrees/radian).
7.7.10 Displaying Data: Custom Menus — Details
Related Topics:
• Custom Menus — Overview (p. 82)
• Data Displays: Custom Menus — Details
(p. 207)
• Keyboard/Display — Overview
(p. 80)
• CRBasic Editor Help for DisplayMenu()
Menus for the CR1000KD Keyboard/Display can be customized to simplify
routine operations. Viewing data, toggling control functions, or entering notes are
common applications. Individual menu screens support up to eight lines of text
with up to seven variables.