Standard Active Last Updated: Feb 24, 2025 Track Document
ASTM D8475-25

Standard Guide for Mixing Layer Height Determination by Laser-Based Ceilometer

Standard Guide for Mixing Layer Height Determination by Laser-Based Ceilometer D8475-25 ASTM|D8475-25|en-US Standard Guide for Mixing Layer Height Determination by Laser-Based Ceilometer Standard new BOS Vol. 11.07 Committee D22
$ 69.00 In stock
ASTM International

Significance and Use

5.1 Ceilometers are devices used by national weather services, regulators, and researchers around the globe to determine the cloud base altitude by means of a backscattered light beam. Cloud base altitude is defined as the base height of the lowest opaque cloud layer (1).3 The ceilometer light source is based on laser technology; therefore, it is a type of atmospheric lidar instrument. Lidar is the acronym for light detection and ranging, and was developed as a remote sensing technique after the invention of lasers in the 1960s (2).

5.2 Lidars are used to precisely measure distances and properties of distant objects. The performance of a ceilometer as a type of lidar system relies on how efficiently a photon can travel through the atmosphere and return to its point of origin due to aerosol backscattering. Having a time-sampling period adjustable over a wide range and adjustable height-sampling intervals, the ceilometer can provide observations on the vertical structure of the planetary boundary layer.

5.3 The instrument’s high temporal and spatial resolution are especially helpful in aerosol (particle pollution) and cloud studies when investigating the evolution of specific layers in the atmosphere since significant changes in atmospheric properties can occur over periods of a minute or less and over distances of tens of meters. Using lidar as a remote sensing tool includes the unobtrusive nature of the probing, which does not contaminate the measured parcel of air, and the option of integrating layer-specific stratified data into column density information. Ceilometers, as laser instruments, have potential safety issues that can be addressed through existing standards, such as IEC criteria for electronic systems, and should comply with national and regional safety regulations.

Scope

1.1 This guide covers the application of laser-based ceilometers to measure local mixing layer heights (MLH).

1.2 The MLH measurements are expressed in SI units. No other units of measurement are used in this guide.

1.3 The applicability of specific regulatory limitations and criteria is not addressed in this guide.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Price:
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Book of Standards Volume: 11.07
Developed by Subcommittee: D22.11
Pages: 7
DOI: 10.1520/D8475-25
ICS Code: 07.060