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Filtering – B&G Deckman User Manual

Page 174

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User variables

12.15

number 7 represents true wind direction, if you look further towards the
top of the list in the [variables] section of j_varsXX.d. Also in the line
above we can see that the new variable has no calibration file (shown by
null.cal) and a filtering file named MA_TWD.fil.

All that remains now is to create the relevant filtering and calibration
files.

Filtering

A subdirectory of your data directory is called filters. In here you must
create the filtering files which you specified in the [UserVariables]
section.

The filtering file will usually contain two numbers: the first is the type
of filtering (see table below),while the second (and occasionally third)
defines the filtering.

Filtering
function

Damping type

Other numbers (or notes)

1 Ordinary

exponential

Inverse of required damping
time in secs/5

2 Exponential,

for 360°

Inverse of required damping
time in secs/5

3 Exponential,

for 180°

Inverse of required damping
time in secs/5

4 two

term

Kalman filter

(refer to B&G)

5

band pass -
mainly for rate
gyros

(refer to B&G)

6

k

term

moving
average

Calculates a moving average
(see below)

7

3rd

order

Chebyshev

Damping in secs