Fuel is the single most import supply during war. Consider that the US Military is employing over 25,000 vehicles
during Operation Iraqi Freedom. Most fuel is obtained locally, and must be characterized to ensure proper operation of
these vehicles. Determination of fuel properties is currently determined using a deployed chemical laboratory.
Unfortunately, each sample requires in excess of 5 hours to characterize. To overcome this limitation, we have
developed a portable fuel analyzer capable of determine 7 fuel properties that allow determining fuel usage. The
analyzer uses Raman spectroscopy to measure the fuel samples without preparation in 2 minutes. The challenge,
however, is that as distilled fractions of crude oil, all fuels are composed of hundreds of hydrocarbon components that
boil at similar temperatures, and performance properties can not be simply correlated to a single component, and
certainly not to specific Raman peaks. To meet this challenge, we measured over 500 diesel and jet fuels from around
the world and used chemometrics to correlate the Raman spectra to fuel properties. Critical to the success of this
approach is laser excitation at 1064 nm to avoid fluorescence interference (many fuels fluoresce) and a rugged
interferometer that provides 0.1 cm-1 wavenumber (x-axis) accuracy to guarantee accurate correlations. Here we
describe the portable fuel analyzer, the chemometric models, and the successful determination of these 7 fuel properties
for over 30 unknown samples provided by the US Marine Corps, US Navy, and US Army.