Examine separate atmowpheric features individually
Previous impelentation combined all the detected atmospheric features
together to calculate metric values. This commit evaluates metric values
for each atmospheric feature individually and takes sum of them.
Adjust smoothing box size
Smoothing box size is extended to 0.016 * nchan (factor was 0.004
previously). Set upper limit depending on the width of the atmospheric
feature (nchatm * 0.2).
