AIDJEX Bulletin #40 - Polar Science Center - University of Washington

DATA PROCESSING
Following the field experiment, the data from each camp were assembled
for further processing. Only fixes satisfying the truncated fix criterion
were used. These fixes were scanned to weed out fixes which were clearly in
error by comparison with the rest of the data. The algorithm used for this
purpose compared each fix with the median position of the 10 fixes preceding
and the 10 fixes following it. On the first pass through the data, a fix was
rejected if it differed from the median value by more than 10 km.
second pass, a fix was rejected if it differed by more than 1 km.
On the
Azimuth
fixes were treated in the same way, an azimuth measurement being rejected if
it differed by more than 10' from the median value.
The raw position measurements were processed using smoothing techniques
given by Kalman and Bucy [1961] to produce estimates of the position, velocity,
and acceleration of each station. The problem was formulated in terms of a
state vector Xn at time t,, and a measurement vector 2,. X, contains the
CARIROU-SNOWBIRD
APRIL I975 - idAY 1976
SEPARATION - I20 km
f 4- W
a c 20
3 0 ~
Fig. 10. Velocity and
velocity differences
occurring during the
main experiment.
t
K
Q,
-
L l
OO 5 IO 15 20
VELOCITY DIFFEHENCE (cm sect)
*On
CAR I BOU
APRIL 1975-MAY 1976
I
-L
OO 5 10 15 20
VELOCITY (cm sec-'1
0)
IO
a
97