- 37: PROP, Site 3, Fri 14-Jun-1996 22:12:14 GMT, Entered prop-vane boom alignment
The prop-vane wind direction at station #3 looked incorrect, so
John checked the boom direction parameter on the prop-vane and
found it to be equal to zero. John entered the correct value,
138.5 degrees. John recall entering a nominal value of 135.0
when he and Kurt aligned the prop-vane to the boom, so it is
likely that the prop has also forgotten this alignment value of
the optical encoder.
- 41: PROP, Site 3, Sat 15-Jun-1996 15:00:39 GMT, Prop-vane alignment
The wind direction at site 3 for the period 0000-1400 GMT, June 15,
matches the wind direction at site 2 very well. This suggests that
the boom alignment parameter in the prop-vane is okay.
Thus we will not make a special site visit to check the boom alignment
at site 3, but we will check it next time we lower the mast at that
site.
- 396: PROP, Site 1, Thu 01-Aug-1996 00:57:28 GMT, RMYoung prop installed
Since we have been suspicious of the bearings on the prop at site 1,
we replaced it with our only spare - the RMYoung prop. This required
some station software changes by Matt.
Matt found that there were cabling and direction alignment problems
with this new prop which he fixed on site. We will check the direction
tomorrow, since the alignment was not precisely done.
- 494: PROP, Site all, Wed 23-Oct-1996 17:40:21 GMT, Post calibration check of PROP-VANE
A performance check was done on the propeller-vane instruments
after FLATLAND96 operations. This included the 3 PAM III units and
the one RM Young unit. Starting threshold and prop pitch
calibrations were checked.
The starting thresholds were below 0.5 m/s for all instruments. The
prop pitch calibrations were a different story. Unfortunately the
incorrect prop pitch calibration factors were used in the instruments
during FLATLAND96. The pitch values corresponded to 23cm propellers used
with the ASTER sensors while 18cm propellers were used in FLATALND96.
Since the transfer function to convert raw data to calibrated data is
a simple multiplier factor, based on the prop pitch, we can correct
the data.
The table below gives the correct prop pitch for the propellers used
during FLATLAND96. The table also provides the correction factor to used
to correct the data. This factor will be applied to the NETCDF data set.
The raw data set will not be modified.
Sensor (old pitch) PROP S/N PITCH Correction Factor station
001 (310) 44341 303 0.98 PAM 1
002 (309) 48267 299 0.97 PAM 2
003 (308) 44344 302 0.98 PAM 3
RMYoung (300) 44341 303 1.01 PAM 1
NOTE: The RM YOung instrument replaced sensor 001 at site 1 on Aug. 1, 1996.