Adding a systematic bias
With the unrollOMG command your able add a systematic bias to the data. The bias overwrites the provided .merged-file so it's best to make a backup of the original .merged-file before using unrollOMG.
The program has numerous options to contaminate the data, try a few and compare the results with the 2D option in swathed. For example:
cp original_data.merged 4deg_pos_roll.merged
unrollOMG -draft 1.5 -roll_offset 4.0 4deg_pos_roll.merged
-draft x.x making sure it first applies the draft before the roll correction
-roll_offset x.x roll bias
The 2D option requires a r4 (dtm):
First get the boundaries then do the make_blank, tor4 and weigh_grid functions:
getBounds original_data.merged
getBounds 4deg_pos_roll.merged
make_blank roll_bias -boundsof original_data.merged
weigh_grid -beamwidth 1.0 roll_bias *merged
Now check the results with the 2D option:
swathed -locate roll_bias *.merged
Other unrollOMG options are:
-justport or -juststbd
-llshift 0.2 -0.005
-flipheave
-negheave
-leverarm x.x y.y z.z
-pitch_rate_scale 0.5
-lag 0.3
-add_draft 3.51
-draft 1.3 (always use this in combination with roll offset)
-apply_pitch or
-pitch_offset 3.0
-apply_roll (-flip_roll) or
-roll_offset 3.0
-roll_scale 0.5
Last modified: 23-07-'06, Pim.
