Novel approach for tomographic reconstruction of gas concentration distributions in air: Use of smooth basis functions and simulated annealing

Drescher, Anushka C.; Gadgil, Ashok; Price, Phillip N.; Nazaroff, William W.

doi:10.1016/1352-2310(95)00295-2

Cited by 64 publications

(50 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since then there have been improvements in speed and spatial resolution (e.g. Drescher et al, 1996;Fischer et al, 2001), but to our knowledge all experiments have been restricted to the laboratory environment so far.…”

Section: Introductionmentioning

confidence: 99%

Longpath DOAS tomography on a motorway exhaust gas plume: numerical studies and application to data from the BAB II campaign

et al. 2004

View full text Add to dashboard Cite

Abstract. This paper presents a procedure for performing and optimizing inversions for DOAS tomography and its application to measurement data. DOAS tomography is a new technique to determine 2-and 3-dimensional concentration fields of air pollutants or other trace gases by combining differential optical absorption spectroscopy (DOAS) with tomographic inversion techniques. Due to the limited amount of measured data, the resulting concentration fields are sensitive to the inversion process. Therefore detailed error estimations are needed to determine the quality of the reconstruction. In this paper we compare different row acting methods for the inversion, present a procedure for optimizing the parameters of the reconstruction process and propose a way to estimate the error-fields by numerical studies. The procedure was applied to data from the motorway emission campaign BAB II. Two dimensional NO 2 cross sections at right angles to the motorway could be reconstructed qualitatively well at different meteorological situations. Additionally we present error fields for the reconstructions which show the problems and skills of the used measurement setup. Numerical studies on an improved setup for future motorway campaigns show, that DOAS tomography is able to produce high quality concentration maps.

show abstract

Section: Introductionmentioning

confidence: 99%

Longpath DOAS tomography on a motorway exhaust gas plume: numerical studies and application to data from the BAB II campaign

et al. 2004

View full text Add to dashboard Cite

show abstract

“…12 The authors and others 12,13 have shown that the smooth basis functions minimization (SBFM) approach 14 can provide the desired field of concentration with a relatively sparse beam geometry. This could have been applied to reconstruct the field of concentration over the emission source area, but would suffer the same disadvantage as the DIAL and previous CT geometries of not being capable to estimate the emission rates.…”

mentioning

confidence: 99%

Localizing Gaseous Fugitive Emission Sources by Combining Real-Time Optical Remote Sensing and Wind Data

Hashmonay

Yost

1999

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

This paper presents a new approach to localize point emissions from ground-level fugitive gaseous air pollution sources. We estimate the crosswind plume's ground-level peak location downwind from the source by combining smooth basis functions minimization (SBFM) with pathintegrated optical remote sensing concentration data acquired along the crosswind direction in alternating beam path lengths. Peak location estimates, in conjunction with real-time measured wind direction data, are used to reconstruct the fugitive source location. We conducted a synthetic data study to evaluate the proposed peak location SBFM reconstruction. Furthermore, the methodology was validated with open-path Fourier transform infrared concentration data collected with wind direction data downwind from a controlled point source. This approach was found to provide reasonable estimates of point source location. The field study reconstructed source location was within several meters of the real source location.

show abstract

“…In the SBFM algorithm, a known smooth basis function with unknown parameters is chosen to characterize the plume. By minimizing the error function between the observed and predicted PIC, the unknown parameters can be estimated (Drescher et al, 1996;Hashmonay et al, 1999;Wu et al, 1999). We applied this algorithm to reconstruct the test maps with two plumes that were both close to the origin.…”

Section: Resultsmentioning

confidence: 99%

“…Another series of test maps (n ¼ 36) were generated with larger SD (¼ 4) at the same locations. Previous studies also used the Gaussian distributions to generate the test maps (Drescher et al, 1996;Verkruysse and Todd, 2005) and thus allowed the researchers to directly compare the input parameters to the parameters obtained from the reconstructed algorithm . The observed PIC (PIC obs ) of the nine beam paths were calculated by integrating the simulated Gaussian distributions and were defined as follows:…”

Section: Generation Of Test Maps and Associated Picmentioning

confidence: 99%

“…Several researchers have applied optical remote sensing (ORS) instruments with the computed tomography (CT) technique to reach this goal (Byer, 1979;Wolfe and Byer, 1982). However, the involvement of complicated CT beam geometry composed of more than one ORS instrument or multiple detectors limited its real-world application (Drescher et al, 1996;Samanta and Todd, 2000).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluating the performance of the horizontal radial plume mapping technique for locating multiple plumes

Chang¹,

2012

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

This paper evaluated the feasibility of using the horizontal radial plume mapping (HRPM) technique to locate multiple emission sources via computational simulation. Seventy-two test maps, each having two Gaussian distributions, were generated in a twodimensional domain. The HRPM technique with the non-negative least square (NNLS) algorithm was then applied to reconstruct the plumes, assuming a nine-beam scanning beam geometry. The NNLS algorithm successfully reconstructed the source locations of 68 of the 72 test maps. However, when one of the plumes was near the origin, the NNLS did not always identify the peak locations correctly. Furthermore, when the two plumes were spaced closely, the NNLS tended to reconstruct a wide plume covering both plumes instead of separating them due to the resolution limitation of the current nine-beam geometry. In the sensitivity analysis, five sets of random error (1%, 5%, 10%, 20%, and 30%) were added in the path-integrated concentration (PIC) from the 72 test maps, and thus, an additional 360 reconstructions were implemented. Robust results were obtained when the noise added was less than 20%. The results generally support the implementation of the NNLS algorithm in the HRPM technique as described in the U.S. Environmental Agency (EPA) Other Test Method 10 (OTM-10).Implications: The methodology evaluated in this paper provides near-real-time estimates about the locations of multiple emission sources. The involved optical remote sensing instruments can monitor large spatial areas (e.g., landfills) in a costeffective way.

show abstract

Novel approach for tomographic reconstruction of gas concentration distributions in air: Use of smooth basis functions and simulated annealing

Cited by 64 publications

References 5 publications

Longpath DOAS tomography on a motorway exhaust gas plume: numerical studies and application to data from the BAB II campaign

Longpath DOAS tomography on a motorway exhaust gas plume: numerical studies and application to data from the BAB II campaign

Localizing Gaseous Fugitive Emission Sources by Combining Real-Time Optical Remote Sensing and Wind Data

Evaluating the performance of the horizontal radial plume mapping technique for locating multiple plumes

Contact Info

Product

Resources

About