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SEPA
United States
Environmental Protection
Agency
Optical Remote Sensing
Background
Vertical and Horizontal Radial Plume Mapping (VRPM and HRPM) are new analytical methods developed by APPCD
and Arcadis that allow for rapid and direct measurement of air pollutant emissions from area sources. VRPM and HRPM
use open-path optical measurements to determine path-averaged pollutant concentrations near emission sources.
Open-path instruments utilize infrared, visible, or ul-
traviolet light, projected over extended distances, to
sample spectroscopically the intersected air column,
providing a representative measurement of average
emissions from the area source. Open-path tech-
niques provide near real-time, in-situ measurements
and can be configured along multiple paths, allowing
for the assessment of concentration gradients. Cur-
rently utilized open-path instruments include: Fourier
Transform InfraRed (FUR), Tunable Diode Laser (TDL),
and Ultraviolet Differential Optical Absorption Spec-
troscopy (UV-DOAS).
The multi-path pollutant concentration data gener-
ated by the open-path instrument are combined with
wind speed and wind direction information and pro-
cessed with the VRPM and HRPM algorithms to yield a
mass emission flux for the source and give area source
concentration profiles.The HRPM algorithm can be used to generate concentration profiles for area sources. Control of
systems and computations are highly automated, allowing for generation of real-time flux emission information."
Wind
Direction
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Instrument
Vertical
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Extended Area
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Ground
Retrorc (lectors
Vertical Radial Plume Mapping (VRPM)
Outcomes
The method has undergone verification studies and has been reduced to protocol form in EPA Test Method OTM 10,
entitled Optical Remote Sensing for Emission Characterization from Non-point Sources, 2006, US EPA Technology
Transfer Network Emission Measurement Center. Web Site: http://www.epa.gov/ttn/emc/prelim.html.
Office of Research and Development
National Risk Management Research Laboratory, Air Pollution Prevention and Control Division
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Results
Capabilities
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