Atmospheric Pollution – EO Browser Script

Custom Script (adapted by us)

var values = [ 1.0*1e-5, 
               2.0*1e-5,
               3.0*1e-5, 
               4.0*1e-5, 
               5.0*1e-5,
               6.0*1e-5 ]; //value of NO2 in mol/m2

return colorBlend(NO2, values,
   [
    [ 64/255,  27/255, 134/255], //  -> 1.0*1e-5 = #401B86
    [ 37/255,  70/255, 201/255], //  -> 2.0*1e-5 = #2546C9
    [ 42/255, 212/255,  36/255], //  -> 3.0*1e-5 = #2AD424
    [240/255, 236/255,  37/255], //  -> 4.0*1e-5 = #F0EC25
    [240/255, 117/255,  55/255], //  -> 5.0*1e-5 = #F07537
    [219/255,  58/255,  76/255]  //  -> 5.0*1e-5 = #DB3A4C
   ]
  );
  • Custom scripts are java script code, used to control the visualization and processing of satellite images with Sentinel Hub. They allow the user to quickly calculate different band combinations and visualize them, without previously downloading data. Sentinel Playground and EO Browser are web applications, that allow easy access to free satellite data provided by the European Space Agency (ESA) and The National Aeronautics and Space Administration(NASA). They also provide an environment for creating custom scripts. Text source: https://www.sentinel-hub.com/docs/Custom_script_tutorial.pdf
  • On the page Atmospheric Pollution – Satellite Data & Imagery, we analysed the NO2 in 2019 compared to 2020 by using the normal EO browser Sentinel-5P facilities.
  • However, when studying the resulted images, we noticed the color intervals were too large and so only extremely significant differences were plotted with a different color. [See images in section Bucharest NO2 Comparison – Satellite Facilities – very similar color]
  • Consequently, we adapted the code to our requirements so as to be able to clearly distinguish any change and the results show an obvious decrease of NO2 emissions in Bucharest 2020. [See images in section Bucharest NO2 Comparison – EO Browser Custom Script – differences in the level of air pollution are shown in corresponding colors]

Bucharest NO2 Comparison – Satellite Facilities

  • Regard below the original script intervals, which were too large (the color code of the two images below):
    [ 64/255,  27/255, 134/255], //  -> 2.5*1e-5 = #401B86
    [ 37/255,  70/255, 201/255], //  -> 5.0*1e-5 = #2546C9
    [ 42/255, 212/255,  36/255], //  -> 7.5*1e-5 = #2AD424
    [240/255, 236/255,  37/255], //  -> 1.0*1e-4 = #F0EC25
    [240/255, 117/255,  55/255], //  -> 2.5*1e-4 = #F07537
    [219/255,  58/255,  76/255]  //  -> 5.0*1e-4 = #DB3A4C
April 06, 2019April 06, 2020

Bucharest NO2 Comparison – EO Browser Custom Script

  • Regard below the script intervals adapted by our team (the color code of the two images below): 
    [ 37/255,  70/255, 201/255], //  -> 2.0*1e-5 = #2546C9
    [ 42/255, 212/255,  36/255], //  -> 3.0*1e-5 = #2AD424
    [240/255, 236/255,  37/255], //  -> 4.0*1e-5 = #F0EC25
    [240/255, 117/255,  55/255], //  -> 5.0*1e-5 = #F07537
    [219/255,  58/255,  76/255]  //  -> 5.0*1e-5 = #DB3A4C
April 06, 2019April 06, 2020