PYE/NFOV/M1 - Intermittent missing data

During the Pt Reyes deployment of the NFOV, the instrument experienced intermittent data 
gaps due to communications problems.  Data gaps occurred for the following date ranges:
20050718-20050723
20050727-20050730
20050803-20050804
20050813-20050816
20050820-20050822
20050826-20050827
20050830-20050902
20050908-20050910

• Calibrated Zenith Radiance, 673nm(radiance_673nm)
• time_offset
• head_temp
• time
• base_time
• tube_temp
• cosine_solar_zenith_angle
• raw_counts_870nm
• raw_counts_673nm
• Calibrated Zenith Radiance, 870nm(radiance_870nm)

• Raw data stream - documentation not supported

PYE/NFOV/M1 - Intermittent data gaps

Intermittent data collection of the NFOV.  Data collection not successful regularly during 
day light hours but generally caught up during the nighttime hours.  Occasionally the 
system stopped collecting altogether and a reboot of the network components was required to 
restart collection. Data gaps are largest 18 through 23 of July and 27 through 30 July.

• time_offset
• Calibrated Zenith Radiance, 673nm(radiance_673nm)
• base_time
• tube_temp
• raw_counts_870nm
• cosine_solar_zenith_angle
• lat
• Calibrated Zenith Radiance, 870nm(radiance_870nm)
• alt
• head_temp
• time
• lon
• raw_counts_673nm

• Raw data stream - documentation not supported

SGP/RSS/C1 - Stability and nonlinearity corrections

From the very beginning after deployment in May 2003 we observed several effects that we 
did not anticipate during the pre-deployment lab test.   They were: (1) Rapid drop in 
responsivity; (2) Responsivity having 1/lambda wavelike periodicity; (3) Appearance of 
nonlinearity within 3 months; (4) Larger than expected diurnal wavelength changes and long term 
wavelength drift. 

Right away we responded with development of correction algorithms and methods.  (1) and 
(2) are corrected to within 2-3% with biweekly lamp calibrations; (3) Nonlinearity factor 
is derived from calibration data and applied in correction; and (4) is efficiently 
corrected with Fourier correlation algorithm applied to every spectrum (once a minute).

Furthermore we perform Langley regression processing  (not a part of official data stream) 
that corrects longer term drifts in responsivity and  should correct calibration lamp 
biases.  The Vo's from Langley regressions are available via RSS  web page.

The overhaul of the instrument is planned to eliminate or at least reduce  nonlinerarity 
stability problems.  We hope that after the overhaul data processing would  be simplified 
and the frequency of calibrations would be reduced.

• AVHRR satellite images for Darwin from BOM (RAW)(raw)

• sdf_diff
• sdf_dn
• Wavelength of spectrum data(wavelength)
• Radiation, Shortwave, Downwelling, Diffuse(diffuse)
• blue_shift
• sdf_th
• Radiation, Shortwave, Downwelling, Direct normal(directnormal)
• red_shift
• Radiation, Shortwave, Downwelling, Global(totalhorizontal)