PYE/TSI/M1 - Misalignment

The TSI was not aligned with true north.

• Pixel count: number total in zenith circle(region.zenith.count)
• Pixel count: number thin in horizon area(region.horizon.count.thin)
• Percent opaque cloud(percent.opaque)
• Pixel count: number opaque in horizon area(region.horizon.count.opaque)
• Pixel count: number thin in zenith circle(region.zenith.count.thin)
• Pixel count: number thin in sun circle(region.sun.count.thin)
• Pixel count: number total indeterminant(count.unknown)
• Percentage thin cloud(percent.thin)
• Pixel count: number total in horizon area(region.horizon.count)
• Pixel count: number total in processed circle(count.sky)
• Pixel count: number total thin(count.thin)
• Pixel count: number below horizon in image(count.sub.horz)
• Pixel count: number total in sun circle(region.sun.count)
• Pixel count: number opaque in sun circle(region.sun.count.opaque)
• Pixel count: number total opaque(count.opaque)
• Pixel count: box, outside mirror area(count.box)
• Pixel count: number opaque in zenith circle(region.zenith.count.opaque)
• Pixel count: camera and sun strip mask(count.mask)
• Pixel count: number total between horizon and processed circle(count.sub.proczen)

• JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

• (MPEG data stream - documentation not yet available)

• PNG data stream - documentation not supported(png)

PYE/MPL/M1 - wrong temperature calibration

Wrong calibration coefficients were applied to the temperature values.  These are 
engineering housekeeping data only.  The scientifically relevant measurements were unaffected.

• Detector Temperature(detector_temp)
• Laser Temperature(laser_temp)
• Filter Temperature(filter_temp)
• Instrument Temperature(instrument_temp)

PYE/MWR/M1 - tipping angles

Obstacles above the horizon were in the field of view of the MWR at the lowest tipping 
elevation angle of 19.5 degrees. The AOS stack to the north and trees to the south affected 
the tip scan measurements at 3 airmasses. This problem was corrected by removing 
observations at the lowest angle from the MWR tip configuration.

• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Temperature correction coefficient at 31.4 GHz(tc31)

PYE/TSI/M1 - water in lens

The lower half of the TSI images were blurry due to water in the camera lens and/or 
filter. The problem was corrected when both were cleaned.

• Relative \'strength\' of direct sun(sun.strength)
• Pixel count: number total in zenith circle(region.zenith.count)
• Pixel count: number thin in horizon area(region.horizon.count.thin)
• Percent opaque cloud(percent.opaque)
• Pixel count: number opaque in horizon area(region.horizon.count.opaque)
• Pixel count: number thin in zenith circle(region.zenith.count.thin)
• Pixel count: number thin in sun circle(region.sun.count.thin)
• Pixel count: number total indeterminant(count.unknown)
• Percentage thin cloud(percent.thin)
• Pixel count: number total in horizon area(region.horizon.count)
• Pixel count: number total in processed circle(count.sky)
• Pixel count: number total thin(count.thin)
• Pixel count: number below horizon in image(count.sub.horz)
• Pixel count: number total in sun circle(region.sun.count)
• Pixel count: number opaque in sun circle(region.sun.count.opaque)
• Pixel count: number total opaque(count.opaque)
• Pixel count: box, outside mirror area(count.box)
• Pixel count: number opaque in zenith circle(region.zenith.count.opaque)
• Pixel count: camera and sun strip mask(count.mask)
• Pixel count: number total between horizon and processed circle(count.sub.proczen)

• JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

• (MPEG data stream - documentation not yet available)

• PNG data stream - documentation not supported(png)

• Raw data stream - documentation not supported(raw)

PYE/MWR/M1 - Reprocessed: Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive the precipitable 
water vapor (PWV) and liquid water path (LWP) from the MWR brightness temperatures were 
based on the Liebe and Layton (1987) water vapor and oxygen absorption model and the Grant 
(1957) liquid water absorption model.

Following the SHEBA experience, revised retrievals based on the more recent Rosenkranz 
(1998) water vapor and oxygen absorption models and the Liebe (1991) liquid water absorption 
model were developed. The Rosenkranz water vapor absorption model resulted a 2 percent 
increase in PWV relative to the earlier Liebe and Layton model.	The Liebe liquid water 
absorption model decreased the LWP by 10% relative to the Grant model. However, the 
increased oxygen absorption caused a 0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was 
particularly significant for low LWP conditions (i.e. thin clouds encountered at SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and Clough, TGARS v. 43, 
pp 1102-1108, 2005) that the half-width of the 22 GHz water vapor line from the HITRAN 
compilation, which is 5 percent smaller than the Liebe and Dillon (1969) half-width used in 
Rosenkranz (1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more accurate retrievals. 
Accordingly, revised MWR retrieval coefficients have been developed using MONORTM, which 
utilizes the HITRAN compilation for its spectroscopic parameters.  These new retrievals 
provide 3 percent less PWV and 2.6 percent greater LWP than the previous retrievals based on 
Rosenkranz (1998).

At Point Reyes, the original coefficients implemented in March 2005 were based on a 
version of the Rosenkranz model that had been modified to use the HITRAN half-width at 22 GHz 
and to be consistent with the water vapor continuum in MONORTM.  These retrievals yielded 
nearly identical results to the MONORTM retrievals.

The MONORTM-based retrieval coefficients became active at PYE.M1 20050506.

Note: The PYE.M1 MWRLOS data for 20050201-20050506 have been reprocessed
to apply the MONORTM-based retrievals for all time. The reprocessed data
were archived in April 2007.  The TIP data have not been reprocessed.

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)

PYE/MWR/M1 - Reprocessed: Calibration corrected

On May 28 1:30 GMT the NFOV radiometer was placed in the field of view of the MWR tip 
calibration. Almost immediately calibration of the MWR was compromised resulting in incorrect 
brightness temperatures and overestimation of both PWV and LWP. 

On July 15 the NFOV radiometer was moved away from the MWR and the instantaneous 
calibration values jumped back to normal. The median values returned to normal on July 17 around 
2100.

The LOS data were reprocessed using interpolated values for the calibration coefficients.  
The reprocessed data are available from the ARM Archive effective December 7, 2005.  
NOTE: the format of the reprocessed data are slightly different than the format of the 
original data and the data available before and after the reprocessed data period.  The 
quality of the data are not affected, just the format.

The MWRTIP data can not be reprocessed and should be used with caution.

• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 31.4 GHz sky signal(sky31)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.4 GHz goodness-of-fit coefficient(r31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 31.4 GHz sky signal(tipsky31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)

PYE/MWRP/M1 - Bias in Ground Relative Humidity Measurement

On June 17 2005, the MWRP was re-installed at PYE after the Super Blower was replaced by 
the old style dew blower. The relative humidity ground sensor in the dew blower is not as 
accurate. This resulted in a negative relative humidity bias of about 5.9 %. In other 
words the MWRP sensor was underestimating the relative humidity. The bias was determined by 
comparing MWRP measurements with SMET and radiosonde measurements. The MP.cfg file for 
the MWRP was changed to reflect this bias on 09/02/2005 and will take effect on 09/03/2005 
0000 GMT

• Raw data stream - documentation not supported(raw)

• Surface water vapor density at instrument(surfaceWaterVaporDensity)
• Ambient surface relative humidity(surfaceRelativeHumidity)

PYE/MWR/M1 - New software version (4.15) installed

A problem began with the installation of MWR.EXE version 4.12 in July 2002. The software 
had been upgraded from a "DOS" to a "Windows"-compiled program to address an earlier 
problem.  The software upgrade corrected the earlier problem but introduced a new one that 
caused line-of-sight observing cycles to be skipped, a 15% reduction in the number of tip 
curves, and saturation of CPU usage. Software versions 4.13 and 4.14 also produced these 
problems.

The new MWR software, version 4.15, was installed on 9/13/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• 23.8 GHz Blackbody signal(bb23)
• Sky Infra-Red Temperature(sky_ir_temp)
• Mixer kinetic (physical) temperature(tkxc)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 23.8 GHz sky signal(sky23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• (tknd)
• 31.4 GHz blackbody(bb31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Blackbody kinetic temperature(tkbb)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• 31.4 GHz sky signal(sky31)
• MWR column precipitable water vapor(vap)
• Ambient temperature(tkair)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.4 GHz goodness-of-fit coefficient(r31)
• Mixer kinetic (physical) temperature(tkxc)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz sky signal(tipsky31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Ambient temperature(tkair)
• 23.8 GHz Blackbody signal(bb23)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• (tknd)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)

PYE/MPL/M1 - Erroneous temperatures

The temperature readings for the laser, detector, and instrument are erroneous.  Incorrect 
calibration factors; data should not be used.  This time period is prior to the official 
start of the PYE deployment.

• Detector Temperature(detector_temp)
• Laser Temperature(laser_temp)
• Instrument Temperature(instrument_temp)