TWP/SKYRAD/C1 - PSPs and NIP: Persistent bias

The NIP/Eppley comparison shows that around solar noon,
the NIP is low relative to the Eppleys by about 4% with
this fraction decreasing slowly toward dawn and dusk. 
At very low sun angles, the NIP irradiance exceeds that
from the Eppleys, presumably because of the roll off in
the Eppley's cosine response at those angles.

Larger discrepancies arise between the NIP and and direct
beam calculated from the Eppleys during periods of sun
following rain events. Significant examples of this
phenomenon occurred on October 10 at 02 GMT and 05 GMT
and on October 13 at 20 GMT. In the latter case, the rain
had actually occurred the previous evening.  

We noticed another rain related peculiarity in the NIP
data.  On several occasions, when a rain event followed
a period of full sun, the NIP actually overshot zero and
went negative by about 10 watts (this is an estimated
value only) and persisted for several minutes.  Examples
occurred on October 16, 17, and 31.

In the morning, the sun is apparently blocked by a line
of trees until about 2030 GMT because large but very brief
discrepancies often occur at that time of day.  In the
afternoon, there is often convection over the main part
of Manus Island to the west which blocks the direct beam.

Another likely explanation is dew on the sensors.  I have
requested that the RESET team examine the sensors after
dawn during their next visit (February 1997).  This phenomenon
occurs on November 4, 12, 13, 15, 17, 19, 20, 22, 27, 28, 30.

Throughout the Manus record, there is a distinct tendency
for the sum of the direct plus diffuse SW to be greater than
the corresponding global PSP. The magnitude of the difference
on average fluctuates around 2-3%. There was an increase in
the average percent difference on about 19980509, roughly
corresponding with the reset visit.  However, the daily
average percent differences exhibit a large variability
around this mean, with a range from 0 - 8% for the period
19980509 - 19980731.  Since the beginning of data collection
rarely has the daily average difference been negative. While
differences of a few percent should be expected, I believe
that having these differences always biased warrants closer
scrutiny.  One would typically expect changes in these daily
average differences to be highly correlated with RESET visits,
which is not obvious in the data record, and to randomly switch
sign given a large enough sample size, which we don't have yet.
I recommend that we monitor this to make sure there's not an
unknown SMALL system grounding problem or Campbell logging
program glitch that is causing this bias.

• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)

TWP/SKYRAD/C1 - PSP: Removal of shading arm

The shading arm for the SKYRAD shaded PSP was removed while instrument
comparisons were being performed by the ARCS RESET team.

• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)

TWP/SKYRAD/C1 - PSPs and NIP: Periods of shortwave radiometer discrepancies

The agreement between the NIP and the direct beam calculated from the
shaded and unshaded PSPs is usually within 5%. However, during these
periods there were larger discrepancies of 5-10%.

• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)

TWP/SKYRAD/C1 - PSPs and NIP: Brief discrepancies, unknown cause

Observed anomalously large discrepancies between the NIP and the PSPs.

• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)

TWP/SKYRAD/C1 - NIP: Moisture inside NIP

The NIP took on a significant amount of moisture during a rainy period
that ended on 970719.  From this date until the RESET visit in August,
the NIP data is corrupted.  The errors are large (often greater than
100 W/m^2 in the direct beam) in the morning but tend to converge to
the expected values in the afternoon.  In general, NIP data from this
period should be used with extreme caution.

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)

TWP/SKYRAD/C1 - NIP: Anomalously low values

The NIP appears to be reporting anomalously low values (based on
comparisons with other shortwave instruments).

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)

TWP/SKYRAD/C1 - IRT affected by rain or shutter

During this time period, the SKYRAD IRT was affected by rain
events.  Water collected on the IRT lens resulting in
elevated and invalid measurement of the sky brightness
temperature.  If the front optic was not dried after a heavy
rain, the data contamination could persist for several days.

The original solution to the problem was to have the local
observers clean the front lens after rains.  In April 1998,
a rain shutter was installed, but it did not become fully 
functional until Aug 9, 1998.

After the rain shutter was installed, the IRT data was
invalid during rain events while the shutter was closed
but ok again immediately after the shutter re-opened.

The configuration of the IRT was changed Oct 19, 2001.
The IRT was mounted such that the field of view is directed
downward at a 30 degree elevation angle and reflected
to the vertical by a front-surfaced, gold-plated mirror.
This configuration prevents rain from directly striking
the lens and collecting in the lens barrel.

Data from 10/96-3/99 were examined and times when the
data are invalid are identified below.  Data from 4/99-10/01
also contain periods of invalid data, but it is left to
the data users to identify those periods and filter the
data according to their needs.

10/12/96 21:00 - 10/14/96 00:00
10/16/96 13:00 - 10/16/96 21:00
10/21/96 04:00 - 10/21/96 23:00
11/09/96 06:00 - 11/09/96 22:00
11/10/96 08:00 - 11/11/96 03:00
11/23/96 17:00 - 11/24/96 03:00
11/25/96 00:00 - 11/25/96 14:00
12/06/96 17:00 - 12/06/96 22:00
12/07/96 01:00 - 12/07/96 06:00
12/11/96 21:00 - 12/11/96 23:00
12/12/96 05:00 - 12/12/96 18:00
12/16/96 03:00 - 12/16/96 23:00
12/19/96 02:00 - 12/20/96 03:00
12/21/96 10:00 - 12/22/96 03:00
12/22/96 20:00 - 12/23/96 07:00
12/27/96 01:00 - 12/27/96 11:00
12/30/96 06:00 - 12/30/96 23:00
01/01/97 21:00 - 01/02/97 01:00
01/10/97 01:00 - 01/10/97 09:00
01/12/97 06:00 - 01/12/97 23:59
01/14/97 01:00 - 01/15/97 23:00
01/17/97 01:00 - 01/17/97 10:00
01/18/97 18:00 - 01/18/97 23:59
01/19/97 17:00 - 01/19/97 23:00
01/20/97 10:00 - 01/21/97 02:00
01/27/97 15:00 - 01/27/97 23:59
01/30/97 16:00 - 01/30/97 23:59
02/01/97 03:00 - 02/01/97 13:00
02/02/97 05:00 - 02/03/97 01:00
02/09/97 00:00 - 02/09/97 03:00
02/10/97 04:00 - 02/11/97 07:00
02/12/97 11:00 - 02/12/97 22:00
02/15/97 00:00 - 02/15/97 03:00
02/16/97 06:00 - 02/16/97 20:00
02/17/97 10:00 - 02/18/97 01:00
02/18/97 04:00 - 02/19/97 23:00
02/24/97 00:00 - 02/24/97 21:00
02/25/97 03:00 - 02/25/97 09:00
02/26/97 01:00 - 02/26/97 07:00
03/01/97 01:00 - 03/01/97 12:00
03/26/97 01:00 - 03/27/97 03:00
04/07/97 13:00 - 04/08/97 02:00
04/11/97 03:00 - 04/11/97 06:00
04/12/97 00:00 - 04/12/97 05:00
04/12/97 12:00 - 04/12/97 18:00
04/15/97 15:00 - 04/15/97 19:00
04/15/97 22:00 - 04/16/97 10:00
04/16/97 12:00 - 04/16/97 23:59
04/22/97 15:00 - 04/22/97 21:00
04/27/97 18:00 - 04/27/97 21:00
04/29/97 13:00 - 04/29/97 20:00
05/01/97 04:00 - 05/01/97 23:00
05/03/97 03:00 - 05/03/97 20:00
05/13/97 13:00 - 05/14/97 23:00
05/16/97 19:00 - 05/16/97 23:59
05/18/97 06:00 - 05/18/97 21:00
05/20/97 02:00 - 05/20/97 21:00
05/22/97 02:00 - 05/22/97 21:00
05/25/97 03:00 - 05/25/97 23:00
05/26/97 04:00 - 05/26/97 11:00
05/27/97 04:00 - 05/27/97 07:00
06/24/97 13:00 - 06/24/97 21:00
06/30/97 19:00 - 07/01/97 06:00
07/04/97 03:00 - 07/04/97 23:59
07/07/97 15:00 - 07/08/97 20:00
07/11/97 13:00 - 07/11/97 21:00
07/12/97 10:00 - 07/12/97 20:00
07/15/97 19:00 - 07/16/97 21:00
07/17/97 18:00 - 07/18/97 05:00
07/18/97 12:00 - 07/19/97 21:00
07/21/97 06:00 - 07/21/97 23:00
08/06/97 21:00 - 08/07/97 07:00
08/07/97 15:00 - 08/07/97 23:00
08/26/97 08:00 - 08/26/97 17:00
09/23/97 20:00 - 09/23/97 21:00
09/25/97 04:00 - 09/25/97 09:00
09/25/97 21:00 - 09/25/97 23:59
10/01/97 03:00 - 10/01/97 06:00
10/12/97 02:00 - 10/12/97 05:00
10/12/97 08:00 - 10/12/97 22:00
10/13/97 06:00 - 10/13/97 17:00
10/22/97 02:00 - 10/22/97 05:00
10/25/97 22:00 - 10/26/97 05:00
10/27/97 07:00 - 10/27/97 23:00
11/02/97 00:00 - 11/02/97 23:59
11/16/97 04:00 - 11/16/97 08:00
11/16/97 18:00 - 11/16/97 22:00
11/18/97 15:00 - 11/18/97 22:00
11/30/97 03:00 - 11/30/97 20:00
12/17/97 18:00 - 12/18/97 23:00
12/21/97 03:00 - 12/21/97 05:00
12/25/97 02:00 - 12/25/97 08:00
12/26/97 18:00 - 12/27/97 01:00
12/28/97 01:00 - 12/28/97 20:00
12/30/97 09:00 - 12/30/97 23:00
01/03/98 04:00 - 01/03/98 05:00
01/04/98 05:00 - 01/05/98 02:00
02/04/98 19:00 - 02/04/98 23:00
02/05/98 04:00 - 02/06/98 19:00
02/07/98 16:00 - 02/08/98 03:00
02/08/98 12:00 - 02/08/98 21:00
02/09/98 06:00 - 02/10/98 04:00
02/20/98 19:00 - 02/20/98 23:59
02/22/98 09:00 - 02/22/98 21:00
03/16/98 00:00 - 03/16/98 02:00
03/17/98 19:00 - 03/17/98 23:59
03/28/98 15:00 - 03/31/98 03:00
03/31/98 10:00 - 03/31/98 22:00
04/01/98 00:00 - 04/01/98 03:18
04/01/98 06:45 - 04/01/98 10:06
04/02/98 00:28 - 04/05/98 03:45
04/05/98 19:25 - 04/05/98 23:54
04/09/98 00:45 - 04/09/98 16:54
04/10/98 15:15 - 04/10/98 19:28
04/11/98 04:24 - 04/11/98 05:34
04/11/98 06:56 - 04/11/98 23:28
04/12/98 00:15 - 04/12/98 01:56
04/12/98 04:15 - 04/12/98 05:37
04/12/98 15:37 - 04/12/98 16:57
04/12/98 17:15 - 04/12/98 21:37
04/13/98 01:37 - 04/13/98 14:45
04/19/98 05:25 - 04/19/98 06:08
04/19/98 20:15 - 04/19/98 22:15
04/21/98 08:57 - 04/22/98 03:45
04/23/98 21:45 - 04/23/98 21:56
04/27/98 17:56 - 04/27/98 22:08
04/28/98 05:45 - 04/28/98 20:36
04/28/98 23:45 - 04/29/98 05:58
04/30/98 10:57 - 04/30/98 21:58
05/01/98 08:08 - 05/02/98 00:08
05/02/98 07:45 - 05/02/98 22:08
05/03/98 08:35 - 05/03/98 22:55
05/04/98 08:16 - 05/04/98 21:55
05/05/98 07:33 - 05/05/98 22:08
05/06/98 07:55 - 05/06/98 22:07
05/07/98 07:55 - 05/07/98 12:33
05/07/98 13:08 - 05/07/98 22:26
05/08/98 02:45 - 05/08/98 03:08
05/08/98 03:34 - 05/08/98 04:16
05/09/98 02:26 - 05/09/98 02:56
05/09/98 20:55 - 05/09/98 21:08
05/09/98 21:45 - 05/09/98 23:35
05/10/98 15:45 - 05/10/98 18:35
05/11/98 22:08 - 05/11/98 22:45
05/12/98 01:34 - 05/12/98 02:26
05/12/98 13:09 - 05/12/98 20:45
05/13/98 00:25 - 05/13/98 04:28
05/13/98 11:15 - 05/13/98 12:57
05/13/98 13:26 - 05/13/98 18:19
05/13/98 19:45 - 05/14/98 22:08
05/16/98 00:15 - 05/16/98 05:15
05/16/98 07:04 - 05/17/98 01:55
05/17/98 05:25 - 05/17/98 06:33
05/19/98 21:16 - 05/19/98 22:16
05/19/98 22:57 - 05/19/98 23:35
05/21/98 16:57 - 05/21/98 21:15
05/21/98 23:56 - 05/22/98 00:45
05/22/98 01:25 - 05/22/98 02:04
05/22/98 19:15 - 05/22/98 21:56
05/23/98 06:25 - 05/23/98 07:07
05/24/98 06:25 - 05/24/98 07:45
05/24/98 10:45 - 05/24/98 21:33
05/25/98 07:57 - 05/25/98 17:26
05/26/98 19:15 - 05/27/98 00:26
05/27/98 04:35 - 05/27/98 12:26
05/29/98 12:05 - 05/29/98 22:15
05/30/98 01:25 - 05/30/98 02:04
06/01/98 15:57 - 06/01/98 21:45
06/02/98 04:15 - 06/02/98 23:34
06/03/98 04:55 - 06/03/98 05:45
06/03/98 07:45 - 06/03/98 11:17
06/03/98 20:58 - 06/03/98 22:58
06/04/98 01:45 - 06/04/98 02:03
06/04/98 07:45 - 06/04/98 09:15
06/04/98 20:29 - 06/04/98 21:15
06/05/98 02:15 - 06/05/98 03:26
06/05/98 05:15 - 06/05/98 13:26
06/05/98 15:26 - 06/06/98 00:05
06/06/98 08:35 - 06/06/98 20:35
06/06/98 21:56 - 06/06/98 22:26
06/07/98 06:45 - 06/07/98 13:45
06/07/98 20:57 - 06/07/98 23:45
06/08/98 00:29 - 06/08/98 01:29
06/08/98 19:29 - 06/08/98 20:58
06/09/98 03:25 - 06/09/98 03:45
06/09/98 06:35 - 06/09/98 06:58
06/09/98 15:42 - 06/09/98 16:58
06/10/98 09:35 - 06/10/98 21:34
06/13/98 02:25 - 06/14/98 03:05
06/13/98 04:45 - 06/13/98 05:26
06/13/98 20:06 - 06/13/98 23:25
06/13/98 23:45 - 06/14/98 00:15
06/14/98 03:25 - 06/14/98 03:45
06/14/98 15:15 - 06/14/98 18:24
06/14/98 20:55 - 06/14/98 21:15
06/16/98 18:34 - 06/16/98 22:36
06/17/98 06:55 - 06/17/98 08:04
06/17/98 09:54 - 06/17/98 10:26
06/18/98 04:26 - 06/18/98 05:05
06/18/98 05:45 - 06/18/98 07:26
06/18/98 12:58 - 06/18/98 13:16
06/18/98 14:15 - 06/18/98 23:56
06/19/98 00:26 - 06/19/98 00:56
06/19/98 02:15 - 06/19/98 03:04
06/19/98 03:25 - 06/19/98 06:56
06/19/98 07:25 - 06/19/98 08:56
06/19/98 11:45 - 06/20/98 13:46
06/20/98 16:29 - 06/20/98 20:45
06/20/98 23:58 - 06/21/98 01:15
06/22/98 03:45 - 06/22/98 04:34
06/22/98 05:45 - 06/22/98 16:34
06/22/98 19:45 - 06/23/98 01:05
06/23/98 02:04 - 06/23/98 02:55
06/23/98 03:45 - 06/23/98 05:05
06/23/98 05:45 - 06/23/98 07:17
06/23/98 22:06 - 06/24/98 16:25
06/24/98 22:36 - 06/24/98 23:25
06/25/98 00:05 - 06/25/98 00:34
06/27/98 00:55 - 06/27/98 01:16
06/27/98 05:45 - 06/27/98 06:05
06/27/98 21:25 - 06/28/98 08:05
06/28/98 12:26 - 06/28/98 13:45
06/30/98 10:58 - 06/30/98 13:05
06/30/98 13:15 - 06/30/98 17:45
06/30/98 18:15 - 06/30/98 21:45
07/01/98 08:26 - 07/01/98 22:05
07/02/98 11:33 - 07/02/98 21:33
07/03/98 17:33 - 07/03/98 21:45
07/04/98 15:57 - 07/04/98 16:45
07/04/98 21:57 - 07/04/98 22:25
07/05/98 07:15 - 07/05/98 22:56
07/05/98 23:05 - 07/06/98 00:05
07/06/98 03:54 - 07/06/98 06:04
07/06/98 07:04 - 07/06/98 10:04
07/06/98 16:45 - 07/06/98 21:15
07/07/98 04:56 - 07/07/98 05:56
07/07/98 06:26 - 07/07/98 06:56
07/07/98 07:45 - 07/07/98 08:34
07/08/98 01:45 - 07/08/98 02:34
07/08/98 02:56 - 07/08/98 03:27
07/08/98 08:26 - 07/08/98 15:08
07/08/98 16:06 - 07/08/98 16:45
07/08/98 17:28 - 07/08/98 19:28
07/09/98 15:55 - 07/09/98 18:03
07/09/98 21:25 - 07/09/98 22:25
07/09/98 23:05 - 07/09/98 23:45
07/10/98 02:25 - 07/10/98 03:58
07/10/98 23:29 - 07/10/98 23:45
07/12/98 09:25 - 07/12/98 09:45
07/12/98 10:25 - 07/12/98 21:15
07/13/98 01:34 - 07/13/98 02:15
07/13/98 04:15 - 07/13/98 04:26
07/13/98 10:15 - 07/13/98 13:57
07/13/98 15:45 - 07/13/98 21:05
07/14/98 02:25 - 07/14/98 02:35
07/14/98 03:15 - 07/14/98 06:25
07/14/98 12:56 - 07/14/98 17:05
07/15/98 03:25 - 07/15/98 05:25
07/15/98 18:15 - 07/15/98 19:55
07/15/98 20:55 - 07/15/98 22:35
07/16/98 03:25 - 07/16/98 06:15
07/16/98 08:35 - 07/16/98 12:15
07/16/98 15:04 - 07/16/98 23:25
07/17/98 10:55 - 07/17/98 13:25
07/19/98 03:35 - 07/19/98 09:15
07/19/98 10:57 - 07/19/98 14:26
07/19/98 15:35 - 07/19/98 18:26
07/19/98 19:55 - 07/19/98 21:15
07/19/98 21:25 - 07/19/98 21:45
07/20/98 01:45 - 07/20/98 02:04
07/20/98 10:15 - 07/20/98 11:45
07/20/98 12:04 - 07/20/98 13:04
07/20/98 16:04 - 07/20/98 22:25
07/20/98 16:05 - 07/20/98 22:25
07/20/98 22:45 - 07/20/98 23:25
07/21/98 01:15 - 07/21/98 01:57
07/21/98 02:34 - 07/21/98 03:45
07/21/98 04:26 - 07/21/98 05:45
07/21/98 06:57 - 07/21/98 07:04
07/21/98 11:45 - 07/21/98 12:35
07/22/98 01:15 - 07/22/98 03:45
07/22/98 05:45 - 07/22/98 22:35
07/22/98 23:35 - 07/23/98 03:15
07/23/98 05:15 - 07/23/98 09:35
07/23/98 17:45 - 07/23/98 19:56
07/23/98 20:45 - 07/23/98 21:56
07/24/98 01:26 - 07/24/98 01:45
07/24/98 04:26 - 07/24/98 04:45
07/24/98 10:15 - 07/24/98 12:15
07/24/98 12:35 - 07/24/98 16:45
07/25/98 07:03 - 07/25/98 13:26
07/26/98 04:25 - 07/26/98 04:45
07/26/98 13:57 - 07/26/98 18:15
07/27/98 09:45 - 07/27/98 09:58
07/27/98 12:05 - 07/28/98 10:25
07/28/98 23:26 - 07/29/98 00:05
07/29/98 00:45 - 07/29/98 01:08
07/29/98 04:58 - 07/29/98 05:26
07/29/98 06:05 - 07/29/98 07:45
07/29/98 16:57 - 07/29/98 18:35
07/30/98 02:45 - 07/30/98 03:45
07/30/98 19:57 - 07/31/98 00:24
07/31/98 07:15 - 07/31/98 08:35
07/31/98 09:04 - 07/31/98 09:45
07/31/98 12:25 - 07/31/98 13:45
08/01/98 00:00 - 08/01/98 00:15
08/01/98 03:15 - 08/01/98 23:05
08/04/98 15:56 - 08/04/98 16:45
08/05/98 06:56 - 08/05/98 07:45
08/06/98 06:45 - 08/06/98 07:15
08/06/98 14:45 - 08/06/98 17:04
08/07/98 05:33 - 08/07/98 07:33
08/09/98 04:15 - 08/09/98 05:33
08/09/98 07:33 - 08/09/98 07:56
08/10/98 19:57 - 08/10/98 21:35
08/11/98 10:04 - 08/11/98 10:15
08/12/98 08:04 - 08/12/98 09:55
08/13/98 16:15 - 08/13/98 16:45
08/14/98 22:04 - 08/14/98 22:15
08/15/98 02:04 - 08/15/98 02:55
08/15/98 04:15 - 08/15/98 04:45
08/15/98 05:25 - 08/15/98 05:45
08/15/98 15:35 - 08/15/98 15:45
08/18/98 07:15 - 08/18/98 07:35
08/18/98 09:15 - 08/18/98 10:27
08/18/98 14:45 - 08/18/98 17:05
08/19/98 15:54 - 08/20/98 10:15
08/27/98 22:10 - 08/28/98 00:45
08/28/98 04:05 - 08/28/98 05:25
09/02/98 05:05 - 09/02/98 05:15
09/03/98 03:15 - 09/03/98 03:25
09/03/98 10:55 - 09/03/98 11:04
09/05/98 20:04 - 09/05/98 21:35
09/07/98 09:45 - 09/07/98 10:05
09/07/98 21:45 - 09/07/98 22:15
09/09/98 05:04 - 09/09/98 06:04
09/09/98 07:35 - 09/09/98 08:45
09/09/98 20:57 - 09/10/98 00:33
09/10/98 06:15 - 09/10/98 07:04
09/10/98 13:55 - 09/10/98 14:24
09/12/98 14:34 - 09/12/98 15:15
09/12/98 17:05 - 09/12/98 17:35
09/13/98 16:55 - 09/13/98 17:04
09/14/98 06:04 - 09/14/98 06:25
09/15/98 08:55 - 09/15/98 09:15
09/15/98 19:45 - 09/15/98 20:55
09/17/98 01:35 - 09/17/98 03:15
09/17/98 08:15 - 09/17/98 09:04
09/17/98 12:55 - 09/17/98 14:04
09/17/98 21:55 - 09/17/98 23:24
09/18/98 11:15 - 09/18/98 12:55
09/18/98 14:45 - 09/18/98 16:55
09/21/98 03:34 - 09/21/98 06:45
09/21/98 15:56 - 09/21/98 16:45
09/21/98 19:04 - 09/22/98 20:55
09/22/98 22:25 - 09/22/98 23:24
09/23/98 03:56 - 09/23/98 05:15
09/23/98 16:04 - 09/23/98 17:15
09/23/98 20:55 - 09/24/98 01:25
09/24/98 02:55 - 09/24/98 03:35
09/24/98 04:25 - 09/24/98 05:56
09/26/98 02:15 - 09/26/98 03:35
09/26/98 08:15 - 09/26/98 08:35
09/26/98 08:45 - 09/26/98 13:24
09/27/98 13:05 - 09/27/98 13:24
09/28/98 03:26 - 09/28/98 03:55
09/29/98 05:45 - 09/29/98 06:15
09/29/98 11:04 - 09/29/98 11:55
09/29/98 19:34 - 09/29/98 21:25
09/30/98 00:05 - 09/30/98 03:15
09/30/98 14:35 - 10/01/98 13:24
10/01/98 14:45 - 10/01/98 16:25
10/02/98 20:45 - 10/02/98 21:35
10/04/98 00:15 - 10/04/98 01:15
10/04/98 02:25 - 10/04/98 08:35
10/05/98 13:15 - 10/05/98 16:57
10/06/98 16:45 - 10/06/98 18:57
10/06/98 21:45 - 10/06/98 22:57
10/08/98 02:15 - 10/08/98 02:45
10/09/98 19:04 - 10/09/98 20:15
10/13/98 01:55 - 10/13/98 03:15
10/15/98 05:55 - 10/15/98 06:35
10/16/98 04:04 - 10/16/98 04:35
10/16/98 22:36 - 10/17/98 00:45
10/17/98 07:24 - 10/17/98 09:15
10/19/98 10:55 - 10/19/98 11:15
10/20/98 03:15 - 10/20/98 04:25
10/23/98 14:45 - 10/23/98 15:15
10/24/98 18:25 - 10/24/98 18:45
10/25/98 00:36 - 10/25/98 00:57
10/25/98 05:15 - 10/25/98 05:24
10/28/98 08:05 - 10/28/98 15:25
10/29/98 06:05 - 10/29/98 06:35
10/29/98 16:15 - 10/29/98 16:55
10/29/98 20:35 - 10/29/98 21:15
10/31/98 11:45 - 10/31/98 15:24
11/01/98 21:35 - 11/01/98 21:45
11/04/98 09:57 - 11/04/98 10:57
11/04/98 11:15 - 11/04/98 12:26
11/05/98 02:34 - 11/05/98 06:00
11/05/98 16:05 - 11/06/98 00:30
11/07/98 11:15 - 11/07/98 11:35
11/07/98 19:24 - 11/07/98 19:57
11/08/98 04:04 - 11/08/98 04:45
11/10/98 02:45 - 11/10/98 03:00
11/10/98 05:00 - 11/10/98 05:30
11/16/98 04:35 - 11/16/98 06:45
11/17/98 01:05 - 11/17/98 06:35
11/17/98 23:24 - 11/18/98 00:45
11/18/98 03:06 - 11/18/98 03:30
11/19/98 00:45 - 11/19/98 01:15
11/19/98 02:04 - 11/19/98 05:36
11/19/98 15:35 - 11/19/98 16:35
11/20/98 00:35 - 11/21/98 01:57
11/21/98 03:24 - 11/21/98 09:05
11/21/98 22:54 - 11/22/98 00:45
11/22/98 23:45 - 11/23/98 02:05
11/23/98 04:54 - 11/23/98 09:00
11/24/98 03:15 - 11/24/98 04:15
11/27/98 07:45 - 11/27/98 08:35
11/28/98 06:24 - 11/28/98 07:15
11/29/98 02:45 - 11/29/98 07:55
11/30/98 20:45 - 11/30/98 21:45
12/01/98 03:35 - 12/01/98 04:15
12/01/98 14:55 - 12/01/98 22:45
12/02/98 02:35 - 12/02/98 13:05
12/02/98 21:15 - 12/02/98 22:15
12/03/98 00:24 - 12/04/98 00:45
12/04/98 06:15 - 12/04/98 06:57
12/04/98 23:55 - 12/05/98 00:45
12/05/98 11:35 - 12/05/98 12:35
12/05/98 16:25 - 12/05/98 17:35
12/05/98 19:15 - 12/06/98 17:35
12/06/98 22:35 - 12/07/98 09:25
12/07/98 12:05 - 12/07/98 13:35
12/07/98 21:45 - 12/08/98 01:15
12/09/98 00:25 - 12/09/98 00:55
12/10/98 02:45 - 12/10/98 04:15
12/11/98 02:55 - 12/11/98 05:36
12/11/98 17:35 - 12/11/98 17:55
12/12/98 00:25 - 12/12/98 17:25
12/12/98 20:05 - 12/12/98 20:56
12/12/98 22:55 - 12/12/98 23:25
12/13/98 00:15 - 12/13/98 00:35
12/13/98 01:35 - 12/13/98 04:25
12/13/98 20:24 - 12/14/98 08:45
12/14/98 14:24 - 12/15/98 21:54
12/17/98 05:35 - 12/17/98 05:45
12/21/98 06:35 - 12/21/98 07:24
12/23/98 17:35 - 12/23/98 18:35
12/24/98 18:25 - 12/24/98 18:45
12/25/98 01:45 - 12/25/98 02:25
12/25/98 04:35 - 12/25/98 14:15
12/25/98 19:15 - 12/25/98 19:55
12/26/98 01:55 - 12/26/98 06:45
12/26/98 17:45 - 12/26/98 18:15
12/27/98 16:15 - 12/27/98 16:35
12/27/98 17:55 - 12/27/98 20:55
12/28/98 13:15 - 12/28/98 13:55
12/28/98 18:15 - 12/28/98 20:55
12/29/98 05:15 - 12/29/98 06:04
12/30/98 03:24 - 12/30/98 05:55
12/30/98 07:15 - 12/30/98 09:15
12/31/98 02:30 - 12/31/98 23:59
01/01/99 00:05 - 01/01/99 01:56
01/01/99 10:15 - 01/01/99 10:45
01/01/99 21:35 - 01/01/99 22:45
01/02/99 00:07 - 01/02/99 00:35
01/02/99 03:35 - 01/02/99 10:25
01/02/99 17:05 - 01/02/99 20:15
01/03/99 08:35 - 01/03/99 08:45
01/03/99 10:24 - 01/03/99 11:04
01/03/99 12:55 - 01/03/99 14:35
01/04/99 13:24 - 01/04/99 13:57
01/05/99 04:45 - 01/05/99 05:05
01/07/99 07:45 - 01/07/99 08:04
01/09/99 21:55 - 01/09/99 22:15
01/10/99 04:15 - 01/10/99 06:35
01/10/99 07:25 - 01/10/99 07:35
01/10/99 08:05 - 01/10/99 08:15
01/15/99 09:15 - 01/15/99 09:24
01/15/99 14:45 - 01/15/99 15:45
01/16/99 04:55 - 01/16/99 06:05
01/18/99 05:55 - 01/18/99 07:15
01/18/99 17:15 - 01/18/99 17:35
01/18/99 20:05 - 01/18/99 20:15
01/19/99 05:03 - 01/19/99 05:15
01/19/99 13:45 - 01/19/99 13:55
01/19/99 15:24 - 01/19/99 15:34
01/19/99 17:05 - 01/19/99 17:45
01/19/99 20:35 - 01/19/99 22:35
01/20/99 03:05 - 01/20/99 03:24
01/20/99 03:55 - 01/20/99 19:45
01/21/99 05:55 - 01/21/99 10:35
01/21/99 14:45 - 01/21/99 17:55
01/21/99 19:35 - 01/21/99 21:15
01/21/99 22:57 - 01/22/99 18:45
01/22/99 22:45 - 01/23/99 00:04
01/23/99 02:24 - 01/23/99 04:45
01/23/99 05:15 - 01/23/99 06:05
01/24/99 13:45 - 01/24/99 15:15
01/25/99 17:24 - 01/25/99 18:24
01/25/99 23:45 - 01/26/99 00:15
01/29/99 22:56 - 01/29/99 23:15
01/30/99 07:04 - 01/30/99 07:45
01/30/99 16:35 - 01/30/99 16:45
01/30/99 19:55 - 01/30/99 23:15
01/31/99 00:55 - 01/31/99 01:35
01/31/99 02:55 - 01/31/99 03:24
01/31/99 06:55 - 01/31/99 08:24
01/31/99 15:55 - 01/31/99 16:15
01/31/99 17:55 - 01/31/99 18:25
01/31/99 21:35 - 02/01/99 05:25
02/01/99 13:15 - 02/01/99 13:55
02/01/99 18:45 - 02/01/99 19:04
02/03/99 03:34 - 02/03/99 04:55
02/03/99 08:24 - 02/03/99 08:45
02/03/99 16:55 - 02/03/99 21:45
02/03/99 23:45 - 02/04/99 03:15
02/04/99 15:15 - 02/04/99 15:24
02/04/99 21:55 - 02/05/99 15:55
02/06/99 14:45 - 02/06/99 15:15
02/07/99 02:15 - 02/07/99 02:35
02/08/99 09:24 - 02/08/99 17:15
02/08/99 22:05 - 02/09/99 13:45
02/09/99 19:05 - 02/09/99 19:35
02/10/99 03:05 - 02/10/99 07:05
02/12/99 00:25 - 02/12/99 04:05
02/13/99 20:55 - 02/14/99 09:15
02/14/99 22:05 - 02/14/99 22:45
02/14/99 23:25 - 02/14/99 23:45
02/15/99 04:55 - 02/15/99 05:25
02/15/99 08:45 - 02/16/99 04:05
02/17/99 15:45 - 02/17/99 16:24
02/18/99 01:05 - 02/18/99 01:15
02/18/99 02:15 - 02/18/99 02:25
02/20/99 06:55 - 02/20/99 07:15
02/20/99 22:55 - 02/20/99 23:25
02/21/99 03:24 - 02/21/99 04:05
02/21/99 15:24 - 02/21/99 17:05
02/21/99 19:05 - 02/21/99 20:24
02/21/99 21:55 - 02/21/99 22:35
02/22/99 00:45 - 02/22/99 01:45
02/22/99 05:55 - 02/22/99 07:15
02/22/99 11:45 - 02/22/99 12:15
02/22/99 13:35 - 02/22/99 13:55
02/22/99 14:24 - 02/22/99 14:45
02/24/99 07:35 - 02/24/99 07:45
02/24/99 16:56 - 02/25/99 05:55
02/25/99 22:45 - 02/25/99 23:55
02/26/99 02:15 - 02/26/99 03:04
02/26/99 04:45 - 02/26/99 05:15
03/01/99 23:45 - 03/02/99 00:55
03/02/99 04:45 - 03/02/99 04:55
03/03/99 01:35 - 03/03/99 02:15
03/03/99 11:35 - 03/03/99 13:15
03/03/99 14:45 - 03/03/99 16:45
03/03/99 21:05 - 03/03/99 21:15
03/05/99 16:45 - 03/05/99 17:05
03/05/99 19:35 - 03/06/99 01:55
03/06/99 10:15 - 03/06/99 10:25
03/06/99 14:24 - 03/06/99 14:45
03/07/99 02:55 - 03/07/99 03:24
03/07/99 03:35 - 03/07/99 05:35
03/07/99 16:45 - 03/07/99 18:45
03/07/99 22:45 - 03/07/99 23:05
03/10/99 00:55 - 03/10/99 01:45
03/10/99 02:35 - 03/10/99 02:55
03/10/99 04:15 - 03/10/99 09:15
03/11/99 02:25 - 03/11/99 02:35
03/12/99 02:25 - 03/12/99 02:35
03/13/99 02:25 - 03/13/99 02:35
03/14/99 02:25 - 03/14/99 02:35
03/15/99 02:25 - 03/15/99 02:35
03/15/99 03:45 - 03/15/99 04:04
03/17/99 13:55 - 03/17/99 14:35
03/17/99 20:15 - 03/17/99 20:35
03/20/99 04:15 - 03/20/99 04:24
03/20/99 05:04 - 03/20/99 05:24
03/20/99 19:45 - 03/20/99 20:25
03/20/99 23:35 - 03/21/99 00:15
03/23/99 10:35 - 03/23/99 11:15
03/25/99 23:15 - 03/25/99 23:55
03/26/99 13:55 - 03/26/99 14:15
03/27/99 18:45 - 03/27/99 20:15
03/28/99 16:15 - 03/28/99 18:06
03/28/99 22:55 - 03/28/99 23:15
03/30/99 02:35 - 03/30/99 02:55
03/31/99 19:45 - 03/31/99 20:35

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)