The IT data set included: acquisition time, acquisition start time, Iridium CEP radius, Iridium latitude, Iridium longitude, GPS fix time, GPS fix attempt, GPS latitude, GPS longitude, GPS horizontal error
, activity count, receive time, repetition count, GPS satellite count, mortality and transmission error.
A shallower weapon trajectory would magnify this induced horizontal error
To see the effect of practice on a pilot's ability to acquire the pathway, a separate analysis of vertical and horizontal error
across trials was conducted.
However, because RMSE tends to inflate larger errors, and because the horizontal error
in this experiment was approximately one order of magnitude greater than vertical error, mean absolute error (MAE) was chosen as the measure of horizontal tracking performance.
For example, if five points were deducted due to 5 horizontal errors
, then 51 would be divided by 56 for a percent score of 91.
At the poles, where illumination rarely provides more than a glimpse of the topography below the crater peaks, we found systematic horizontal errors
of hundreds of meters (hundreds of yards) as well.