Revisiting wind speed measurements using actively heated fiber optics: A wind tunnel study

Near-surface wind speed is typically only measured by point observations. The actively heated fiber-optic (AHFO) technique, however, has the potential to provide high-resolution distributed observations of wind speeds, allowing for better spatial characterization of fine-scale processes. Before AHFO can be widely used, its performance needs...

Measurements and Observations in the XXI century (MOXXI): innovation and multi-disciplinarity to sense the hydrological cycle

To promote the advancement of novel observation techniques that may lead to new sources of information to help better understand the hydrological cycle, the International Association of Hydrological Sciences (IAHS) established the Measurements and Observations in the XXI century (MOXXI) Working Group in July 2013. The group comprises a...

The smart climate observation network that covers all Africa

There is a lack of weather and climate observation stations in Africa, while food production, harvest predictions, and disaster mitigation would benefit from improved data-accessible observation. A new smart and sustainable weather and climate observation network now addresses the important challenge of monitoring the weather in the continent.

Skin effect of fresh water measured using distributed temperature sensing

A phenomenon known as the skin effect-a layer of surface water that is colder than the water beneath it-was previously described in oceanography and verified in lab measurements. Only a few measurements have been done on the skin effect in field conditions, and therefore this phenomenon is relatively unknown. This paper presents measurements...

Mapping high-resolution soil moisture and properties using distributed temperature sensing data and an adaptive particle batch smoother

This study demonstrated a new method for mapping high-resolution (spatial: 1 m, and temporal: 1 h) soil moisture by assimilating distributed temperature sensing (DTS) observed soil temperatures at intermediate scales. In order to provide robust soil moisture and property estimates, we first proposed an adaptive particle batch smoother...

Practical considerations for enhanced-resolution coil-wrapped Distributed Temperature Sensing (discussion)

Fibre optic Distributed Temperature Sensing (DTS) is widely applied in earth sciences. Many applications require a spatial resolution higher than the provided by the DTS instrument. Measurements at these higher resolutions can be achieved with a fibre optic cable helically wrapped on a cylinder. The effect of the probe construction, such as its...

Mapping variability of soil water content and flux across 1–1000 m scales using the Actively Heated Fiber Optic method

The Actively Heated Fiber Optic (AHFO) method is shown to be capable of measuring soil water content several times per hour at 0.25 m spacing along cables of multiple kilometers in length. AHFO is based on distributed temperature sensing (DTS) observation of the heating and cooling of a buried fiber-optic cable resulting from an electrical...

Comment on ‘‘Capabilities and limitations of tracing spatial temperature patterns by fiber-optic distributed temperature sensing’’ by Liliana Rose et al.

A resonating rainfall and evaporation recorder

We propose a novel, accurate quantification of precipitation and evaporation, as needed to understand fundamental hydrologic processes. Our system uses a collection vessel placed on top of a slender rod that is securely fixed at its base. As the vessel is deflected, either by manual perturbation or ambient forcing (for example, wind), its...

Carbon monoxide as a tracer of gas transport in snow and other natural porous media

The movement of air in natural porous media is complex and challenging to measure. Yet gas transport has important implications, for instance, for the evolution of the seasonal snow cover and for water vapor transport in soil. A novel in situmulti-sensor measurement system providing high-resolution observation of gas transport in snow is...

Calibrating single-ended fiber-optic raman spectra distributed temperature sensing data

Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installations. The new methods presented are more...

Shade estimation over streams using distributed temperature sensing

The characterization of temporal and spatial distribution of sunlight is essential for understanding energy transport in natural ecosystems. Fiber?optic distributed temperature sensing (DTS) allows meter resolution measurements of temperature at subminute resolution. The difference in temperature due to absorption and reflection of a pair of...

Feasibility of soil moisture monitoring with heated fiber optics

Accurate methods are needed to measure changing soil water content from meter to kilometer scales. Laboratory results demonstrate the feasibility of the heat pulse method implemented with fiber optic temperature sensing to obtain accurate distributed measurements of soil water content. A fiber optic cable with an electrically conductive armoring...

A distributed stream temperature model using high resolution temperature observations

Distributed fiber?optic temperature sensing for hydrologic systems

Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We discuss the spectrum of fiber-optic tools that may...