A lot of advancement has been made at NOA recently in the research domain of the thermal urban environment, and in particular Surface Urban Heat islands (SUHI) and heat wave mapping. Apart from relevant publications, NOA is co-Leader of the Group on Earth Observations (GEO) SB-04 task on Global Urban Observations. In addition, Athens is identified as one of the eight supersites worldwide within SB-04, meaning that the international co-leaders and scientific contributors of SB-04 will apply their methodologies to the urban environment of Athens, so as to reveal the value of complementary Earth Observation methodologies for the study of the Urban Environment. In BEYOND, NOA is advancing its ground level and software infrastructures with the real time acquisition and high level post-processing of land surface temperature (LST) measurements to build and populate a relevant UHI patterns database that will improve the insight into possible trends and comparison between cities.
A system for real time and online monitoring of the thermal urban environment using geostationary satellite images is being developed at the IAASARS/NOA. This activity is developed towards attaining the objective to derive urban biophysical parameters for characterizing urban land surface-atmosphere. Currently, no Earth Observation system provides data with adequate spatial and temporal resolution for studying and monitoring the SUHI. The wealth of information revealed could be useful to a range of applications. Furthermore, the optimized exploitation of the data could be tailored for different purposes, with several different end-users such as urban climate modelers, health responders and energy demand suppliers.
Specifically, the system comprises separate modules including satellite image acquisition from MSG-SEVIRI EUMETCast station installed at and operated by IAASARS/NOA, cloud screening, derivation of LST from clear sky thermal infrared radiances, and downscaling of LST imagery down to 1 km spatial resolution using Support Vector Regression Machines and iterative gradient boosting. Our vision is to develop the system for all the cities with population >1M and view angle below 60 ̊ in the SEVIRI disk (117 cities in total). The system will eventually offer four significant advantages:
- It will exploit the quarter-hourly temporal resolution of SEVIRI imagery,
- It will enhance the spatial resolution of the retrieved LST data down to 1 km,
- It will cover a large number of cities around the world, and
- The derived LST data will be available in real time and online.
NOA successfully organized the “Global Urban Observation and Monitoring from Space” Workshop, a high-level targeted two-day workshop that took place in Athens, Greece, on 31st March and April 1st 2014. The highlights of the workshop can be seen in "Athens Urban Workshop Highlights" Presentation.