TWP/SMET/C1 - Upper wind sensor failure

The upper wind speed sensor was binding at low wind speeds.  Comparison to the lower wind 
sensor showed that the upper sensor flat-lines for long periods of time.  The upper 
anemometer was replaced.

Use lower wind sensor data during low wind speeds.

• Upper sensor, wind speed standard deviation(up_spd_sd)
• Upper sensor, wind direction vector average(up_dir_vec_avg)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Upper sensor, wind speed maximum(up_spd_max)
• Upper sensor, wind speed minimum(up_spd_min)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• Upper sensor, wind direction standard deviation(up_dir_sd)