The purpose of this paper is to study the relationship between columnar aerosol optical thickness and ground-level aerosol mass. A set of Sun photometer, elastic backscattering lidar and TEOM measurements were acquired during April 2007 in Lille, France. The PM2.5 in the mixed boundary layer is estimated using the lidar signal, aerosol optical thickness, or columnar integrated Sun photometer si...

A PHOTOMETER is described with which the scotopic candlepowers of very feeble light sources (down to about 10(-9) candle) can be measured. Small spots of radium paint, 2 or 3 mm. in diameter and having candlepowers in the range covered, are now used (Livingston) to plot the dark-adapted visual field, and the present photometer was designed primarily for their calibration. The radium paint emits...

S PART OF A CONTINUING PROGRAM in this laboratory directed toward the improvement of clinical laboratory procedures and instruments, additional modifications (1) of the flame photometer have been devised to obtain the benefits of modern components and circuits. Flame photometers using self-generating photocells have proved to be stable and reliable instruments in hundreds of clinical laboratori...

MonoGraphoMetrics is the science of computing 3D measures from a single image. Several recent research activities have produced theoretical principles and practical tools for extracting 3D measures from uncalibrated photographs. These tools require that the user identifies configurations of edges, which are used to establish constraints or to identify planes in the scene. The process involved i...

This paper describes an improvement in the derivation of integrated water vapour from sun photometer observations of the atmospheric transmission within a near-infrared wavelength band (̃ 940 nm) characterized by strong water vapour absorption. The improvement is obtained by better accounting for out-of-band (OOB) transmittance of the sun photometer filter. Such contribution is usually neglected...

Aerosol measurements have been carried out at Kolhapur (16.41°N 74.13°E) by using newly designed Semiautomatic Twilight Photometer. Some noticeable features of the semiautomatic twilight photometer are improvement in efficiency of the system, growth in signal to noise ratio, augmentation in height resolution, lot of upgrading in the sensitivity of the system, expansion in duration of operation ...

We have applied a comprehensive theory of photometric errors to the design and evaluation of an inexpensive stabilized photometer. The photometer is described in terms of a group of modules, the characteristics of which are described in terms of their effect on specific error coefficients. Procedures described in this paper show how the principles described earlier [Clin, Chem. 20, 1028 (1974)]...