Case Studies

Pollution from road vehicles is regulated to protect ambient air quality and new passenger cars must meet the Euro emissions standards before they can be approved for sale in the EU. However, congested areas such as city centres still suffer from elevated levels of certain pollutants - in particular NO2 , which is associated wi...

Since their introduction, the Euro regulations have significantly reduced exhaust pollution by progressively decreasing the permitted emissions. As a consequence, the low levels of particulate permitted by the next iteration of Euro regulations, Euro 6c, due to be implemented in September 2017, are now beyond the sensitivity of...

Earth-based measurements of solar UV radiation are currently made using complex scanning spectroradiometers, installed at a limited number of monitoring stations worldwide. These instruments are expensive to purchase and maintain, and time consuming to use. The introduction of newer, faster compact CCD array spectroradiometers,...

Brewer spectrophotometers are among the most sophisticated instruments currently used to measure stratospheric ozone and solar UV radiation. Global solar UV radiation entering the spectrophotometer is sampled by a diffusion plate to measure its intensity. The diffusion characteristics of this entrance optic is one of the most i...

Today, the majority of dissolved oxygen measurements made by the oceanographic community are made using amperometric and optical sensors. While the performance of these sensors has improved dramatically over recent years, accurate measurements are still difficult to obtain due to the influence of numerous sources of measurement...

Recognising this need, organisations including the European Space Agency (ESA) now require the instrumentation they use to meet the Quality Assurance Framework for Earth Observation (QA4EO) guidelines, which specify the need for measurement traceability. However, while carefully calibrated on the groundprior to launch, Earth ob...