Title:	INDOEX Aircraft C-130 Radiation Measurements (Valero)

Authors:

	Francisco P. J. Valero and Anthony Bucholtz
	Atmospheric Research Lab
	Scripps Institution of Oceanography
	University of California-San Diego
	Mail Code 0242
	9500 Gilman Dr.
	La Jolla, CA  92093
	Phone:	858-534-8099
	Fax:	858-822-0517
	fvalero@ucsd.edu
	abucholtz@ucsd.edu

1.0 Data Set Overview:

This dataset contains measurements from the Radiation Measurement
System (RAMS), a multi-instrument array mounted on the NCAR C-130
during INDOEX.  Datafiles for each flight of the C-130 during INDOEX
are included (from 16Feb99 to 25Mar99).

2.0 Instrument description:

The RAMS consists of the following:

	Total Solar Broadband Radiometer (TSBR):  Hemispheric 
	field-of-view radiometer with a spectral bandpass from 
	0.2 to 3.9 microns.  Two TSBRs were mounted on the C-130,
	one in a zenith port, the other in a nadir port.  The 
	TSBRs measured the downwelling and upwelling total solar
	irradiance.  Accuracy = approx. 1%

	Fractional Solar Broadband Radiometer (FSBR):  Hemispheric 
	field-of-view radiometer with a spectral bandpass from 
	0.7 to 3.3 microns.  Two FSBRs were mounted on the C-130,
	one in a zenith port, the other in a nadir port.  The 
	FSBRs measured the downwelling and upwelling near-IR solar
	irradiance.  Accuracy = approx. 1%

	Widebandpass Total Direct Diffuse Radiometer (WTDDR): Shadow
	band radiometer with a hemispheric field-of-view and 7 channels
	spanning the visible solar spectrum from the near-UV to the 
	near-IR: 500 nm channel (10 nm bandpass), and six 50 nm bandpass
	channels spanning 400-700 nm (center wavelengths: 425, 475, 525,
	575, 625, 675 nm).  Two WTDDRs were mounted on the C-130, one in 
	a zenith port, the other in a nadir port (the nadir instrument
	did NOT have a shadow-band).  The zenith instrument measured the 
	downwelling solar flux in the given bandpasses.  (Note: Depending 
	on the location of the shadow-band the measured flux could represent 
	the total, direct, or diffuse component of the downwelling solar 
	radiation, but the data given in these files have not been 
	differentiated in this way).  The nadir WTDDR measured the upwelling 
	solar flux in the 7 spectral channels.  Accuracy = approx. 1%

3.0 Data Collection and Processing:

The measurements were collected at a rate of 5 Hz.  No smoothing or averaging
has been done.

The data for all instruments have been filtered to remove sections when the
aircraft was turning (i.e. when the aircraft roll exceeded approximately
+/- 2 deg. from the mean roll during level flight), and when the aircraft
was excessively climbing or descending (i.e. when the aircraft pitch exceeded
approximately +/- 5 deg.).  In addition, sections when the solar zenith 
angle exceeded 70 degrees have been removed.

The remaining data points from the zenith instruments have been corrected to
a level platform by using the aircraft attitude data (pitch, roll, heading)
to adjust the downwelling fluxes to account for the angle of the detector
relative to level.

4.0 Data Format:

Data file structure: 	netCDF 

File naming convention:	The TSBR and FSBR data for each flight have been
			put into one file, while the WTDDR data for each
			flight are in a separate file:

	Broadband data: RAMS.INDOEX.sbrUC1.b1.yymmdd.ssssss.cdf
	WTDDR data:    	RAMS.INDOEX.tddrUC1.b1.yymmdd.ssssss.cdf

Header:			standard netCDF header			

Data Version:		1.0 (9 Aug 1999) PRELIMINARY

Remarks:		Recommend contacting Francisco P. J. Valero or
			Anthony Bucholtz for assistance in using the data.

5.0 References:

None