The differential absorption lidar (DIAL) technique generally assumes that atmospheric optical scattering is the same at the two laser wavelengths used in the DIAL measurement of a gas concentration profile. Errors can arise in this approach when the wavelengths are significantly separated, and there is a range dependence in the aerosol scattering distribution. This paper discusses the errors introduced by large DIAL wavelength separations and spatial inhomogeneity of aerosols in the atmosphere. A Bernoulli solution for determining the relative distribution of aerosol backscattering in the UV region is presented, and scattering ratio boundary values for these solutions are discussed. The results of this approach are used to derive a backscatter correction to the standard DIAL analysis method. It is shown that for the worst cases of severe range dependence in aerosol backscattering, the residual errors in the corrected DIAL O3 measurements were <10 ppbv for DIAL wavelengths at 286 and 300 nm.

Download full-text PDF

Source
http://dx.doi.org/10.1364/ao.24.002827DOI Listing

Publication Analysis

Top Keywords

dial measurements
8
range dependence
8
dependence aerosol
8
aerosol backscattering
8
dial
5
ultraviolet dial
4
measurements profiles
4
profiles regions
4
regions spatially
4
spatially inhomogeneous
4

Similar Publications

Generalizing multiple memories from a single drive: The hysteron latch.

Sci Adv

January 2025

Department of Physics, Pennsylvania State University, University Park, PA, USA.

Far-from-equilibrium systems can form memories of previous deformations or driving. In systems from sheared glassy materials to buckling beams to crumpled sheets, this behavior is dominated by return-point memory, in which revisiting a past extremum of driving restores the system to a previous state. Cyclic driving with both positive and negative strains forms multiple nested memories, as in a single-dial combination lock, while asymmetric driving (only positive strain) cannot.

View Article and Find Full Text PDF

The autonomic nervous system plays a crucial role in regulating physiological processes and maintaining homeostasis through its two branches: the sympathetic nervous system (SNS) and the parasympathetic nervous system. Dysregulation of the autonomic system, characterized by increased sympathetic activity and reduced parasympathetic tone, is a common feature in chronic kidney disease (CKD) and cardiovascular disease. This imbalance contributes to a pro-inflammatory state, exacerbating disease progression and increasing the risk for cardiovascular events.

View Article and Find Full Text PDF

A polarimeter is a common but critical instrument for measuring the optical rotation of chiral compounds, ranging from the pharmaceutical to chemical industry, or even employed in monitoring chemical reactions for research purposes. Developing a portable polarimeter helps to transfer the measurements from the laboratory to on-site detection. Herein, we design a new portable polarimeter with a "hand-held" scale.

View Article and Find Full Text PDF

Background And Hypothesis: The PLA2R antibody test is a valuable first-line diagnostic tool for primary membranous nephropathy (MN), helping to identify PLA2R-related MN and potentially eliminating the need for a kidney biopsy in some individuals. By reducing the reliance on biopsies, the test streamlines diagnosis and improves patient care. However, determining the optimal PLA2R measurement method and cut-off is critical to maximising the benefits of the test and minimising any harms.

View Article and Find Full Text PDF

The present paper was designed to analyze the dimensions of such important bony structures and surgical landmarks, which are used by many clinicians in many surgical interventions, in dry skull, cadaver, and healthy subjects on computed tomography (CT) images, and to determine whether there is a significant difference between these methods, and to obtain reference values from 3 different methods. Eight cadavers and 16 dry skulls and 100 three-dimensional (3D) CT images were studied. Necessary permissions for the study were obtained from Ethics Comittee.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!