TWP/MFRSR/C2 - Incorrect lat/lon/alt recorded in data

The lat/lon/alt values reported in the data files are
incorrect.  The correct values are:

latitude = -0.521
longitude = -166.9153 (MFRSR reports East latitudes as negative)
altitude = 7.1

• altitude above sea levelaltunits(alt)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)

• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• east longitude for all the input platforms.(lon)

• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• east longitude for all the input platforms.(lon)

TWP/MFRSR/C2 - Head not level

The data from the Nauru MFRSR is questionable because either the cosine correction
is bad and/or the head was not level.  These problems cause some total optical
depths to be below the Rayleigh limit ... obviously something is wrong!  The
head was checked for level on 1999/05/12 and it was found to be out of level
so we do know that 'levelness' has been a problem.  We don't yet know if the
cosine correction, too, has been a problem.  In any event the head was 
changed on 99/06/19 and the data from this point on looks very good.

• MFRSR Detector Temperature(mfrsr_temp)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Hemispheric Broadband Irradiance, offset and cosine corrected, broadband scale
  factor applied(hemisp_broadband)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)

• Hemispheric Broadband Irradiance (Approximate), MFRSR(total_hemisp_broadband)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• MFRSR Detector Temperature(mfrsr_temp)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)

• Total Horizontal Irradiance, Broadband Solar(tot1)
• Direct-normal Irradiance, 940 nm(dirn7)
• Diffuse Horizontal Irradiance, 610 nm(dif4)
• Total Horizontal Irradiance, 940 nm(tot7)
• Direct-normal Irradiance, 610 nm(dirn4)
• Total Horizontal Irradiance, 862 nm(tot6)
• Total Horizontal Irradiance, 500 nm(tot3)
• Diffuse Horizontal Irradiance, 665 nm(dif5)
• Diffuse Horizontal Irradiance, 415 nm(dif2)
• Direct-normal Irradiance, 665 nm(dirn5)
• Direct-normal Irradiance, 862 nm(dirn6)
• Diffuse Horizontal Irradiance, 940 nm(dif7)
• Total Horizontal Irradiance, 610 nm(tot4)
• Direct-normal Irradiance, Broadband Solar(dirn1)
• Total Horizontal Irradiance, 665 nm(tot5)
• Direct-normal Irradiance, 500 nm(dirn3)
• Diffuse Horizontal Irradiance, Broadband Solar(dif1)
• Total Horizontal Irradiance, 415 nm(tot2)
• Direct-normal Irradiance, 415 nm(dirn2)
• Diffuse Horizontal Irradiance, 862 nm(dif6)
• Diffuse Horizontal Irradiance, 500 nm(dif3)

TWP/MFRSR/C2 - Estimated calibration errors

The Nauru MFRSR data has been examined for the dates of about 1999/06/21 through 
1999/07/22.  The head temperature is stable, and there's no sign of shading problems.  The 
calibration stability was examined through the use of Langley regressions, and the calibrations 
seem stable and reasonably accurate, to wit:

wavelength     estimated calibration error (negative means MFRSR is too low)
415                -1.6%
500                -1.2%
615                -0.2%
673                -0.6%
870                 0.6%
940                 don't know but probably with 1-2%

Keep in mind that these estimates are from a time period of about 1 month's duration and 
they could change as we receive more data.

• Hemispheric Broadband Irradiance (Approximate), MFRSR(total_hemisp_broadband)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)

• Total Horizontal Irradiance, Broadband Solar(tot1)
• Direct-normal Irradiance, 940 nm(dirn7)
• Diffuse Horizontal Irradiance, 610 nm(dif4)
• Total Horizontal Irradiance, 940 nm(tot7)
• Direct-normal Irradiance, 610 nm(dirn4)
• Total Horizontal Irradiance, 862 nm(tot6)
• Total Horizontal Irradiance, 500 nm(tot3)
• Diffuse Horizontal Irradiance, 665 nm(dif5)
• Diffuse Horizontal Irradiance, 415 nm(dif2)
• Direct-normal Irradiance, 665 nm(dirn5)
• Direct-normal Irradiance, 862 nm(dirn6)
• Diffuse Horizontal Irradiance, 940 nm(dif7)
• Total Horizontal Irradiance, 610 nm(tot4)
• Direct-normal Irradiance, Broadband Solar(dirn1)
• Total Horizontal Irradiance, 665 nm(tot5)
• Direct-normal Irradiance, 500 nm(dirn3)
• Diffuse Horizontal Irradiance, Broadband Solar(dif1)
• Total Horizontal Irradiance, 415 nm(tot2)
• Direct-normal Irradiance, 415 nm(dirn2)
• Diffuse Horizontal Irradiance, 862 nm(dif6)
• Diffuse Horizontal Irradiance, 500 nm(dif3)