Blog from July, 2008

I repositioned the downwind1 gps antenna around 11:30 am, July 13.  I moved it from the top of the adam, where it was under one of the horizontal braces of the PAM tripod, to the top of the brace near the gps antenna for pressure1.

Wireless communication has not been good since the switch to the AP24. So we have changed back to the 180 antenna and will see if things improve. There has been an improvement in the SNR since the antenna cable length was reduced.

The output format of the pressure sensor attached to the pressure reference tank was changed to 1/1000. Also the running average was changed to 30 seconds to provide better resolution. The output rate was left at 1 second.

UPDATE: The averaging was set back to 1 second since we can average the data in post processing.

Tom noticed we had noisy data throughout the night, so I reduced the tx-power of the AP24 from 25 to 20. Based on data_stats the noise has gone away. This dropped the SNR from high 40s to 40. Will monitor.

Due to the on/off wireless today we decide to download the local storage after the AP24 system was back up. All ADAMS had their disks swapped.

Due to the wireless outages we decided to move the .14 network to the AP24 internal antenna. This took place over the course of today. Since the mast had to lowered , wires run, changes to the Ap24 firmware, etc. As a result the SNR from downdwind2 and profile has almost doubled. The tx-power ion the internal was set to 25, gain to 0.

A backup configuration for the previous configuration and the new one were created. They can be found in the AP24 directory file.

Alico-11072008-2300.backup (old)

Alico-12072008-2252.backup (new)

network address for AP24:

internal: 192.168.14..251

external 192.168.12.251

AHATS daily status 7/12/08

Staff: Semmer, Horst, McIntyre

Summary: Max temperature yesterday at z=1.5m, 100 degF.

Fast pressure has been working since 12:00 7/11...start of good operations.

I have inventoried the HATS data to estimate how many hours of good wind
direction are required to obtain a comparable amount of good data for AHATS.
HATS had 4.2 - 7.4 hours of analyzable data per configuration for a total
of 22 hours.  HATS has 175 hours of periods at least 25 minutes long with
wind directions within +/- 30 deg of normal to the array.  Thus we would
like to have 40-45 hours of good wind directions prior to changing from
one configuration to the other.  If we get good wind directions 30% of
the time, this will require 6 days per configuration.  Starting July 11
at 12:00, we have 29.75 days prior to tear-down on the morning of
August 10, minus 3.5 days for reconfigurations or 26.25 days of data
collection.

For more details, see the ahats logbook at
https://wiki.ucar.edu/display/ahatslogbook

Good wind direction: From July 11, 12:00, until July 12, 12:00, we have
had 9.75 hours or 40.6% good wind directions with continuous periods
of at least 25 minutes.  This includes 6.75 hours stable data and
2.92 hours unstable.

Local data storage:
------------------
Swapped all local data storage media yesterday.

Pressure:
--------
Note that dat("p") = dat("P") - dat("Pref"), but that was probably also
true before we sealed the reference side.

(+/- = ~1 std deviation)
p: ok, +/- 0.03 mb
t: ok, +/- 0.4 degC
Pref: ok, range = +/- 1 mb

Profile:
--------
Brief data losses around 23:00, July 10, and 07:00, July 12
(Why weren't all the RF losses on July 10 recovered from local data storage?)

diag: ok
samples.sonic: ok, see above
spd: ok
  ** neutral profiles have an increased gradient above 4m that is possibly
  ** an internal boundary layer caused by the upwind check dam
dir: ok
w: ok
tc: ok
w'w': ok
u*: ok
sigma_w/u*: ok (1.3 at night)
w'tc': ok
T: ok
RH: 4m may be low by less than 1% RH
P: okay

Upwind (hts=3.5):
----------------
See Profile for data loses

diag: ok
samples.sonic: ok, see above for data losses
spd: ok, +/- 14 cm/s (6u has +15 cm/s offset in u)
dir: ok, +/- 3 deg
w: ok, +/- 5 cm/s
tc:  ok, +/- 0.16 deg
w'w': ok, +/- 0.01 m^2/s^2  (30 min avg for second moments)
u*: ok,  +/- 2 cm/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.02 m/s degC
tc'tc': ok, +/- 0.05 degC^2

Lower (hts=3):
-------------
See Profile for data loses

diag: ok
samples.sonic: ok, see above for data losses
spd: ok, +/- 20 cm/s
dir: ok, +/- 6 deg
w: ok, +/- 5 cm/s
tc:  ok, +/- 0.25 deg
w'w': ok, +/- 0.01 m^2/s^2  (30 min avg for second moments)
u*: ok,  +/- 3 cm/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.02 m/s degC
tc'tc': ok, +/- 0.08 degC^2

Upper (hts=4):
-------------
See Profile for data loses

diag: ok
samples.sonic: ok, see above for data losses
spd: ok, +/- 20 cm/s
dir: ok, +/- 5 deg; 6t is about 6.5 degrees off from profile sonic
w: ok, +/- 6 cm/s
tc:  ok, +/- 0.2 deg
w'w': ok, +/- 0.01 m^2/s^2  (30 min avg for second moments)
u*: ok,  +/- 3 cm/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.02 m/s degC
tc'tc': ok, +/- 0.07 degC ^2

AHATS daily status 7/11/08

Staff: Semmer, Horst, McIntyre

Summary:

Max temperature yesterday at z=1.5m, 113 degF!

Steve finished putting cable ties on all the pressure line junctions
this morning at 10:30 am.  The system passed an over-pressure leakdown
test.  Woo Hoo!  At 12:00 (noon) he connected the pressure system
to the reference volume.

The wireless connection between the array and the base was down from
23:10, July 10, until 07:15, July 11.

For more details, see the ahats logbook at https://wiki.ucar.edu/display/ahatslogbook

Good wind direction: Because of the extended wireless outages, we need
to merge the local data storage and rerun covars before I can make a
good assessment

Local data storage:
------------------
Swapped all local data storage media today.

Local data storage from each ADAM was downloaded this morning.

I inventoried (Splus function 'inventory()' in SGS/S directory) the good data statistics from SGS/HATS for the four configurations, running good.dir (min.period=25*60).

good.dir are periods with continuous wind direction within 30 deg of normal to array

good.wx are periods selected for analysis on the basis of stationarity

percent is good.wx/good.dir*100 

Steve completed sealing the fast pressure lines July 11 at 10:30 am PDT.  He used teeny cable ties on all the junctions.   The system passed an over-pressure leakdown test by maintaining a constant pressure.

A separate test was done on the reference tank. It also had a leak at the junction to the tank. This was fixed at 12:00 noon.

eantG and H have died the past two evenings.  Here are the log entries from ap24eth. The later ones without a date are for Jul 11. Times in UTC.

On the night of Jul 10 is the first time I've noticed that a radio reconnects after being disconnected due to extensive data loss. There is one instance, Jul 10 02:40:36, where the sodar antenna, eantI is disconnected, but then reconnects.  In general the sodar antenna has stayed up. It is up now.

My guess is that we are being hit with interference, and that eantG and H are hardest hit because they are transmitting constantly. Using a narrower beam patch antenna rather than the 180-degreen antenna is probably a good idea. We could use the ap24 internal patch antenna.

:24:7F is eantG (profile)
:24:85 is eantH (downwind2)
:24:56 is eantI (sodar)

jul/10 02:37:11 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: connected
jul/10 02:40:24 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: disconnected, extensive data loss
jul/10 02:40:36 wireless,info 00:20:F6:05:24:56@wlan2-Ext-Ant: disconnected, extensive data loss
jul/10 02:40:52 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, extensive data loss
jul/10 02:41:08 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: connected
jul/10 02:41:20 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: connected

jul/10 03:05:03 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: connected
jul/10 03:06:39 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: disconnected, extensive data loss
jul/10 03:06:47 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, extensive data loss
jul/10 04:07:35 wireless,info 00:20:F6:05:24:56@wlan2-Ext-Ant: disconnected, reassociating
jul/10 04:07:35 wireless,info 00:20:F6:05:24:56@wlan2-Ext-Ant: connected

00:00:02 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: connected
00:01:38 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, extensive data loss
00:01:40 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: connected
00:01:41 wireless,info 00:20:F6:05:24:56@wlan2-Ext-Ant: disconnected, reassociating
00:01:41 wireless,info 00:20:F6:05:24:56@wlan2-Ext-Ant: connected
00:05:56 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: disconnected, extensive data loss
00:05:57 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: connected
00:06:16 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, reassociating

06:07:03 wireless,info 00:20:F6:05:24:7F@wlan2-Ext-Ant: disconnected, extensive data loss
06:15:56 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, extensive dat loss
06:15:57 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: connected
06:17:32 wireless,info 00:20:F6:05:24:85@wlan2-Ext-Ant: disconnected, extensive data loss

A pressure check was done after modifying 4 sensors. There was improvement but the leak still existed. Decided to go back to square one by checking the Vaisala line. It was ok. Leakage started as soon as we added the first "T" junction. Further tests showed that the leak could be stopped by adding panduit ties at each junction (3 ties per T). This requires very small ties so an order to Digikey was placed. Should have the ties by tomorrow noon.

After getting the wireless link from downwind2 and profile going this morning we did not realize that pressure1 was also down. It was restarted late this afternoon.

Note by Gordon: this system was still configured to use dhcp - and it lost its lease when the etherants were down. Fixed. 

The pocketec from downwind1 and downwind2 were swapped again today due to the wireless link going down last night. Tom needed data from last night.