TITLE: Twin Otter Three Wavelength Nephelometer Data

AUTHOR(S): 
Brian Mader
Department of Environmental Science and Engineering
Caltech MS 210-41
Pasadena CA 91125
626-395-4410
bmader@cheme.caltech.edu

Richard Flagan
Department Chemical Engineering
Caltech MS 210-41
Pasadena CA 91125
626-395-4383
flagan@caltech.edu

John Seinfeld
Department Chemical Engineering
Caltech MS 210-41
Pasadena CA 91125
626-395-4635
seinfeld@caltech.edu

 
1.0 DATA SET OVERVIEW

Abstract

Airborne measurements of particle light scattering coefficient were measured 
using the Twin Otter aircraft during ACE-Asia.  Measurements were made using a 
Model 3563 TSI three-wavelength nephelometer located onboard a modified De 
Havilland DHC-6 Twin Otter aircraft operated by the Center for Interdisciplinary 
Remotely Piloted Aircraft Studies (CIRPAS).  A total of 19 Research Flights were 
conducted between March 31 and May 1, 2001.  The center of aircraft operations 
was located at the Marine Corps Air Station (MCAS) Iwakuni, Japan and the 
sampling area included portions of the Sea of Japan south and east of the Korean 
Peninsula, the East China Sea between China, Japan and Korea, and the Philippine 
Sea south of Japan.  

2.0 INSTRUMENT DESCRIPTION

Measurements were made using a Model 3563 TSI three-wavelength nephelometer.  
Further information about this instrument is available from 
http://www.tsi.com/particle/products/nephelometers/neph.htm


3.0 DATA COLLECTION AND PROCESSING 

Measured values of light scattering and light backscattering coefficient at 450, 
550 and 700nm were saved on an onboard computer at a rate of 1 Hertz. The 
aircraft latitude, longitude, altitude and atmospheric pressure at the time that 
light scattering measurements were recorded are also included. 

4.0 DATA FORMAT: 

Data file structure is comma delimited ASCII
PI/DATA CONTACT = Mader Brian (Caltech); Flagan Richard (Caltech); Seinfeld John 
(Caltech)
DATA COVERAGE = START: 04022001; STOP: 05012001
PLATFORM/SITE = Twin Otter
SAMPLE COLLECTION INSTRUMENT = TSI Model 3563 Three Wavelength Nephelometer 
LOCATION = mobile
DATA VERSION = 1.0 (11 March 2002) Final
REMARKS = California Institute of Technology ACE-Asia
Date = yyyymmdd
Mission time = seconds
UTC time = hhmmss (UTC)
Lat= Latitude
Long = Longitude
Alt = Altitude (m)
Blue scatter = particle scattering coefficient for light of wavelength 450 nm 
(mega m^-1)
Green scatter = particle scattering coefficient for light of wavelength 550 nm 
(mega meters^-1)
Red scatter = particle scattering coefficient for light of wavelength 700 nm 
(mega m^-1)
Blue backscatter = particle backscattering coefficient for light of wavelength 
450 nm (mega m^-1)
Green backscatter = particle backscattering coefficient for light of wavelength 
550 nm (mega meters^-1)
Red backscatter = particle backscattering coefficient for light of wavelength 
700 nm (mega m^-1)
P(s) = pressure (mb)

5.0 DATA REMARKS

Errant data is labeled as -99999

6.0 REFERENCES:

http://www.tsi.com/particle/products/nephelometers/neph.htm