TWP/MFRSR/C1 - New head/filters installed

On 1999.02.27 a new head was installed with Centronics filters.  This head had been worked 
over on the PNNL testbed prior to deployment. The head temperature is very stable.  
There's no sign of filter drift.  There are a few data gaps of unknown origin.  There are no 
signs of shading or alignment problems. 

There were a lot more Langley events than we had anticipated; this allowed
an assessment of the calibration error:

415 nm  0.6%
500 nm -0.2%
615 nm  0.8%
673 nm  2.3%
870 nm  0.7%

These numbers, although preliminary, can only be described a very good.

• Normalized filter function data, filter 4, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter4)
• Offset subtracted from hemispheric and diffuse broadband data(offset_broadband)
• Normalized filter function data, filter 5, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter5)
• Normalized filter function data, filter 6, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter6)
• Nominal calibration factor, applied to broadband data(nominal_calibration_factor_broadband)
• Data Logger Temperature(logger_temp)
• Time offset from base_time(time_offset)
• Narrowband hemispheric irradiance, filter 4, offset and cosine corrected(hemisp_narrowband_filter4)
• Narrowband Hemispheric Irradiance, Filter 5, offset corrected(hemisp_narrowband_filter5)
• Narrowband Hemispheric Irradiance, Filter 2(hemisp_narrowband_filter2)
• Narrowband hemispheric irradiance, filter 3, offset and cosine corrected(hemisp_narrowband_filter3)
• Narrowband Hemispheric Irradiance, Filter 1, offset corrected(hemisp_narrowband_filter1)
• time_in_seconds_since_volume_start(time)
• Direct Normal Broadband Irradiance, cosine corrected, broadband scale applied(direct_normal_broadband)
• Data logger supply voltage(logger_volt)
• Narrowband hemispheric irradiance, filter 6, nominal wavelength is 935 nm(hemisp_narrowband_filter6)
• Hemispheric broadband irradiance(hemisp_broadband)
• -180.0 - +180.0(alt)
• Ratio of direct_normal_filter2 to diffuse_hemisp_filter2(direct_diffuse_ratio_filter2)
• Ratio of direct_normal_filter1 to diffuse_hemisp_filter1(direct_diffuse_ratio_filter1)
• Ratio of direct_normal_filter4 to diffuse_hemisp_filter4(direct_diffuse_ratio_filter4)
• Detector temperature(head_temp)
• Ratio of direct_normal_narrowband_filter3 to diffuse_hemisp_narrowband_filter3(direct_diffuse_ratio_filter3)
• base time in epoch(base_time)
• Ratio of direct_normal_narrowband_filter6 to diffuse_hemisp_narrowband_filter6(direct_diffuse_ratio_filter6)
• Ratio of direct_normal_filter5 to diffuse_hemisp_filter5(direct_diffuse_ratio_filter5)
• cosine correction, south to north, filter5(cosine_correction_sn_filter5)
• cosine correction, south to north, filter6(cosine_correction_sn_filter6)
• Azimuth angle(azimuth_angle)
• North Latitude(lat)
• cosine correction, south to north, filter1(cosine_correction_sn_filter1)
• Cosine correction, south to north, filter2(cosine_correction_sn_filter2)
• Normalized filter function data, filter 1, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter1)
• Normalized filter function data, filter 2, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter2)
• Cosine correction, south to north, filter3(cosine_correction_sn_filter3)
• Normalized filter function data, filter 3, measured transmittance value obtained
  during bench calibrations(normalized_transmittance_filter3)
• Cosine correction, south to north, filter4(cosine_correction_sn_filter4)
• Alltime hemispheric broadband irradiance(alltime_hemisp_broadband)
• Air mass(airmass)
• cosine correction, west to east, broadband channel(cosine_correction_we_broadband)
• angle of incidence during cosine bench measurements(bench_angle)
• Diffuse Narrowband Hemispheric Irradiance, Filter 1, offset corrected(diffuse_hemisp_narrowband_filter1)
• Diffuse Narrowband Hemispheric Irradiance, Filter 2, offset corrected(diffuse_hemisp_narrowband_filter2)
• Alltime narrowband hemispheric irradiance, filter 2(alltime_hemisp_narrowband_filter2)
• Alltime narrowband hemispheric irradiance, filter 1(alltime_hemisp_narrowband_filter1)
• Alltime Narrowband Hemispheric Irradiance, Filter 6(alltime_hemisp_narrowband_filter6)
• Alltime narrowband hemispheric irradiance, filter 5(alltime_hemisp_narrowband_filter5)
• Alltime Narrowband Hemispheric Irradiance, Filter 4(alltime_hemisp_narrowband_filter4)
• Alltime Narrowband Hemispheric Irradiance, Filter 3(alltime_hemisp_narrowband_filter3)
• lon(lon)
• Cosine correction applied to direct_horizontal_broadband(computed_cosine_correction_broadband)
• Normalized filter function data, filter 6, wavelength value obtained during
  bench calibrations(wavelength_filter6)
• Diffuse Narrowband Hemispheric Irradiance, Filter 3(diffuse_hemisp_narrowband_filter3)
• Diffuse Narrowband Hemispheric Irradiance, Filter 4(diffuse_hemisp_narrowband_filter4)
• Normalized filter function data, filter 4, wavelength value obtained during
  bench calibrations(wavelength_filter4)
• Solar zenith angle(solar_zenith_angle)
• Narrowband diffuse hemispheric irradiance, filter 5, offset and cosine corrected(diffuse_hemisp_narrowband_filter5)
• Normalized filter function data, filter 5, wavelength value obtained during
  bench calibrations(wavelength_filter5)
• Diffuse Narrowband Hemispheric Irradiance, Filter 6, offset corrected(diffuse_hemisp_narrowband_filter6)
• Normalized filter function data, filter 2, wavelength value obtained during
  bench calibrations(wavelength_filter2)
• Normalized filter function data, filter 3, wavelength value obtained during
  bench calibrations(wavelength_filter3)
• Normalized filter function data, filter 1, wavelength value obtained during
  bench calibrations(wavelength_filter1)
• Cosine correction of broadband diffuse, assuming Rayleigh sky at 45 degree
  zenith angle(diffuse_correction_broadband)
• Cosine correction applied to direct_horizontal_narrowband_filter3(computed_cosine_correction_filter3)
• Cosine solar zenith angle(cosine_solar_zenith_angle)
• Cosine correction applied to direct_horizontal_narrowband_filter4(computed_cosine_correction_filter4)
• Cosine correction applied to direct_horizontal_filter1(computed_cosine_correction_filter1)
• Cosine correction applied to direct_horizontal_narrowband_filter2(computed_cosine_correction_filter2)
• Elevation angle(elevation_angle)
• Diffuse Hemispheric Broadband Irradiance, offset corrected(diffuse_hemisp_broadband)
• Cosine correction applied to direct_horizontal_filter5(computed_cosine_correction_filter5)
• Cosine correction applied to direct_horizontal_filter6(computed_cosine_correction_filter6)
• Offset subtracted from direct normal filter4 data(offset_filter4)
• Offset subtracted from upwelling hemispheric filter5 data(offset_filter5)
• Offset subtracted from hemispheric and diffuse filter6 data(offset_filter6)
• Offset subtracted from hemispheric filter1 data(offset_filter1)
• Offset subtracted from upwelling hemispheric filter2 data(offset_filter2)
• Second detector temperature(head_temp2)
• Offset subtracted from direct normal filter3 data(offset_filter3)
• Ratio of direct_normal_broadband to diffuse_hemisp_broadband(direct_diffuse_ratio_broadband)
• Cosine correction, west to east, filter1(cosine_correction_we_filter1)
• Cosine correction, west to east, filter4(cosine_correction_we_filter4)
• Cosine correction, west to east, filter5(cosine_correction_we_filter5)
• cosine correction, west to east, filter2(cosine_correction_we_filter2)
• cosine correction, west to east, filter3(cosine_correction_we_filter3)
• Narrowband Direct Horizontal Irradiance, Filter 6, cosine corrected(direct_horizontal_narrowband_filter6)
• Narrowband Direct Horizontal Irradiance, Filter 5, cosine corrected(direct_horizontal_narrowband_filter5)
• Narrowband Direct Horizontal Irradiance, Filter 4, cosine corrected(direct_horizontal_narrowband_filter4)
• Direct Horizontal Narrowband Irradiance, Filter 3(direct_horizontal_narrowband_filter3)
• Narrowband Direct Horizontal Irradiance, Filter 2, cosine corrected(direct_horizontal_narrowband_filter2)
• Direct horizontal narrowband irradiance, filter 1(direct_horizontal_narrowband_filter1)
• Cosine correction of filter2 diffuse, assuming Rayleigh sky at 45 deg zenith
  angle(diffuse_correction_filter2)
• Cosine correction of filter3 diffuse, assuming Rayleigh sky at 45 deg zenith
  angle(diffuse_correction_filter3)
• Cosine correction of filter1 diffuse, assuming Rayleigh sky at 45 degree zenith
  angle(diffuse_correction_filter1)
• cosine correction, south to north, broadband channel(cosine_correction_sn_broadband)
• Nominal calibration factor, applied to filter4 data(nominal_calibration_factor_filter4)
• Nominal calibration factor, applied to filter5 data(nominal_calibration_factor_filter5)
• Narrowband Direct Normal Irradiance, Filter 5(direct_normal_narrowband_filter5)
• Nominal calibration factor, applied to filter6 data(nominal_calibration_factor_filter6)
• cosine correction, west to east, filter6(cosine_correction_we_filter6)
• Direct normal narrowband irradiance, filter 6, offset corrected(direct_normal_narrowband_filter6)
• Nominal calibration factor, applied to filter1 data(nominal_calibration_factor_filter1)
• Nominal calibration factor, applied to filter2 data(nominal_calibration_factor_filter2)
• Nominal calibration factor, applied to filter3 data(nominal_calibration_factor_filter3)
• Direct Horizontal Broadband Irradiance(direct_horizontal_broadband)
• Cosine correction of filter6 diffuse, assuming Rayleigh sky at 45 deg zenith
  angle(diffuse_correction_filter6)
• Narrowband Direct Normal Irradiance, Filter 3, cosine corrected(direct_normal_narrowband_filter3)
• Direct normal narrowband irradiance, filter 4, offset corrected(direct_normal_narrowband_filter4)
• Cosine correction of filter4 diffuse, assuming Rayleigh sky at 45 deg zenith
  angle(diffuse_correction_filter4)
• Narrowband Direct Normal Irradiance, Filter 1(direct_normal_narrowband_filter1)
• Direct normal narrowband irradiance, filter 2, offset corrected(direct_normal_narrowband_filter2)
• Cosine correction of filter5 diffuse, assuming Rayleigh sky at 45 deg zenith
  angle(diffuse_correction_filter5)

• Diffuse Hemispheric Broadband Irradiance, offset corrected(diffuse_hemisp_broadband)
• Direct Normal Irradiance, MFRSR(direct_norm_broadband)
• Hemispheric broadband irradiance(hemisp_broadband)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)