The continuous measurement of the direct normal, diffuse horizontal, and global horizontal 
components of spectral irradiance (DNI, DHI, GHI) is critical to many environmental science and solar energy applications. This spectral irradiance is modified by changing concentrations of atmospheric trace gases and aerosols, creating a need for continuous monitoring. While many satellites try to retrieve information about these atmospheric constituents, a bottom up approach is critical to validate the satellite data and to measure the actual radiative effect at the surface. EKO Instruments has been an innovative company with tradition in outdoor radiometric measurements with more than half a century of experience in the field of solar spectroradiometry. Recently, EKO has been developing new products and measurement methodologies which are under study at the Izaña Atmospheric Research Center (IARC) from the Agencia Estatal de Meteorologia (AEMET). 

The Research Center is situated on the island of Tenerife, Spain (28.3°N, 16.5°W) at a high-altitude mountain site (2367 m above sea level), presenting an ideal location for evaluating solar radiation sensors and performing Langley calibrations. Furthermore, the site contains high-end instrumentation installed for atmospheric research, with the particularity of being one of the participants of the AERONET network for aerosol monitoring. Hence, a proper evaluation of the atmospheric parameters retrieved with a spectroradiometer can be performed at the test site. 

Methodologies are developed to extend the solar spectrum (280-4000nm) measurements outside of the EKO spectroradiometers wavelength range (300-1100nm) based on radiative transfer models. As well as to estimate other atmospheric parameters such as aerosol optical depth (AOD) based on the spectroradiometer measurements. Adding these additional parameters to the spectral data set will present added value to the research communities in atmospheric and environmental sciences, and in solar energy. Additionally, EKO has introduced a new device, the RSB-01 rotating shadow band, intended to operate with the EKO spectroradiometers to measure the global and diffuse horizontal spectral irradiances, and compute the direct normal spectral irradiance.

With this research project, EKO aims to explore the untapped potential of its spectroradiometers by developing measurement methodologies to quantify atmospheric parameters based on ground-based solar spectral measurements, as well as to evaluate the performance of the instruments recently introduced by EKO.

High-precision control of the STR-32G system orientation.

Not many trackers can accomplish this task. The EKO STR-32G was selected as a platform to install solar irradiance sensors on and provide the researchers at NREL with the ability to move the equipment into any orientation. Read the article

The EKO sun-tracker, model STR-22G, was selected for its reliability and durability by the JMA Antarctic Observation project in 2004. Two sun-trackers are permanently deployed under extreme weather condtions at the Showa Station in Antarctic region ever since. We asked Mr. Mori from the Office of Antarctic Observation at the Japan Meteorological Agency how the sun tracker performed under the most extreme weather conditions.

Mr. Mori explained how they are very satisfied with the two EKO sun-tracker systems which are deployed on-site. One of the great advantages of STR-22 is its reliabity and durability. The compact sun-tracker is very rugged and greatly performs under severe temperatures. Mr. Mori reported that one sun-trackers is used for Direct Normal Irradiance and Diffuse Horizontal Irradiance measurement, and a second unit serves for Long Wave Radiation and Atmospheric Turbidity measurements.

Even though the EKO sun-trackers don't require any regular maintenance, the trackers for the Antarctic project were serviced on a routine basis. The research site is very remote which makes the logistics more difficult. To ensure a year-round operation with zero down-time, there is one extra unit on-site for incidental back-up. A fourth sun-tracker is kept a the EKO service center in Tokyo for a periodic maintenance check. There are a total of 4 units of Sun trackers used in Antarctica observation project. EKO Instruments performs a periodic maintenance check by exchange of one unit every year. The harmonic gears inside the STR-22G have proven to be most durable and smooth running after 14 years.

EKO is committed to develop the best, most stable and reliable products to be deployed under harsh weather conditions. This way EKO could contribute to Antarctic observation project and we like to specially thank Mr. Mori and the people of the Antarctic observation station for their valuable feedback and good partnership.

(Photo provided by Office of Antarctic Observation, Japan Meteorological Agency)

EKO signed up to sponsor the Solar boat team from the University of Antwerp with a MS-80. The ISO 9060: class A pyranometer with fast response and spectrally flat offered is the perfect solution for the team to monitor the performance of the Solar boat. 

The Solar boat built by the team from the university is completely self-powered by the pv panels that cover the entire surface of the boat. It has already participated to races since 2015 and the team plans to participate to 2 other races this year. Those will be the Eco Race Challenge and the Solar & Energy Boat Challenge.

Many challenges await the solar boat team in 2019. The team has the goal to upgrade their boat to the next level and ensure that it can go to a speed of 30km per hours. 

We wish the Solar boat team to beat their own record and to excel in the next races!

Please check their newsletter for more information.

New and innovative techniques are required to gain more knowledge of the ever-changing atmospheric conditions and the effect this has on the environment. Current methods of measuring solar irradiation in the vertical profile of the atmosphere still have limitations and issues concerning measurement uncertainty.

UAV is one of the new methods commonly used in observational studies due to their maneuverability, size, and versatility. The purpose of this study is to construct the Unmanned Aerial System (UAS), based on a quadcopter which includes sensors to measure radiation, temperature, humidity, and pressure to gain a better insight to the vertical structure of the atmosphere and to improve the predictability of weather and climate models further.

Dr. Sheng-Hsiang Wang (Associate Professor of the Department of Atmospheric Sciences, National Central University) an his colleagues in Taiwan have installed the MS-80U and ML-01 on their UAV to measure upward and downward radiation.

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