Determination Of Vertical Profiles Research Articles

On the determination of vertical profiles of temperature, charge concentration, and potential in the surface layer of an aircraft

A “3/2 law” law has been established for the vertical charge concentration profile (i.e., the particle concentration is proportional to temperature to a power of 3/2). The expression is derived for the electric field potential produced by charged particles at the upper boundary of the viscous sublayer, as well as for the density current produced by charged particles moving in the air flow streamlining an aircraft. It is shown that all these parameters increase with altitude and assume maximum values at the turbulent layer surface.

Road Slope Information from GPS-Derived Trajectory Data

The World Solar Challenge was held in 1996, and will be held again in 1999. As part of the University of New South Wales solar car project, global positioning system techniques were used to determine the road slope characteristics of the Stuart Highway running north-south from Darwin to Adelaide. This data formed the basis of a geographic information system to support solar car race strategy. Motivated by this project, a new Kalman filter algorithm for road slope determination has been developed. The state vector in the Kalman filter includes the height and slope of the road, rather than the conventional parameters of height and vertical velocity. In this way the slope can be derived directly within the Kalman filter, the system equations can be more easily developed and the system noise can be significantly reduced. Numerical results confirm that the new Kalman filter algorithm can be easily implemented, and that the accuracy of road slope determination is improved. This algorithm is appropriate for any survey application concerned with the determination of vertical profile.

Comment on ‘Determination of vertical profiles of aerosol size spectra from aircraft radiative flux measurements, 1, Retrieval of spherical particle size distributions’ by Kondratyev et al.

Comment on ‘Determination of vertical profiles of aerosol size spectra from aircraft radiative flux measurements, 1, Retrieval of spherical particle size distributions’ by Kondratyev et al.

Reply [to “Comment on ‘Determination of vertical profiles of aerosol size spectra from aircraft radiative flux measurements, 1, Retrieval of spherical particle size distributions’”

Reply [to “Comment on ‘Determination of vertical profiles of aerosol size spectra from aircraft radiative flux measurements, 1, Retrieval of spherical particle size distributions’”

Determination of vertical profiles of aerosol size spectra from aircraft radiative flux measurements: 1. Retrieval of spherical particle size distributions

During the GATE observational program, aircraft radiative flux measurements were taken at several altitudes in the Saharan dust. On the basis of these flux measurements at 28 wavelengths in the 0.4–0.9 μm wavelength region, the corresponding vertical particle size spectra have been inferred. These particle size distributions, calculated by using spherical Mie theory, have been represented by quadramodal combinations of gamma functions. The calculated quadramodal size distributions were characterized by mode radii at 0.1, 0.2, 1.0, and 2.0 μm, with a relatively narrow spread of particle sizes centered about each mode radius. The number density of the smallest particle mode was found to increase with increasing height, while that of the largest particle mode decreased with increasing height. Comparison of deduced particle sizes of a ‘dusty’ day (September 4) and a ‘clear’ day (August 13) showed that the dusty day was characterized far more by the presence of large particles than by an increase in small particle concentration. Heating rates as large as 0.4°C/hour μm were found for September 4, 1974.