Twomey inversion algorithm

Figure 5. Normalized S mass distribution, China Lake, CA—average of 8 samples. Aerosol segregated by LPl and analyzed by FVFPD. The solid histogram is the mass distribution with respect to the 50% aerodynamic cutoff diameter the dashed histogram is the inverted distribution obtained from LPl calibration data and Twomey (1975) inversion algorithm (a) July2-4, 1978 ("M = 0.765 fig/m ) (b) October 20-22, 1978 (M = 1.702 /ig/m ) (c) September 5-7, 1979 (M =...

Whether particle size distributions can be determined according to the PSD-SE-Method, despite the measurement error of the PSD-SE-Sensor, is examined in the following. Eor this purpose, particle size distributions are calculated from the measured and the simulated extinction cross sections, according to (12.7), with three different inversion algorithms/methods. The inversion with linear smoothing and standardization on = 1 is referred to as Twomey method. With... 

Twomey, S., Comparison of Constrained Linear Inversion and an Iterative Nonlinear Algorithm Applied to the Indirect Estimation of the Particle Size Distribution, J. Comp. Phys. 18 188-200 (1975). 

Riebel and Ldffler [240] obtained an acoustic attenuation spectrum with one transducer pair to infer the particle size distribution. Solids concentrations and particle size distribution were obtained using both the Phillips-Twomey algorithm (PTA) and the relaxation method. The PTA gives a least squares solution by simple linear matrix operations to yield a numerical inversion from the attenuation spectra to the size distribution... 

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