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Sentinel Hub Blog

Shanghai Wetland visualised with REACTIV from 2018–01–01 to 2020–09–11

REACTIV — Implementation for Sentinel Hub Custom Scripts Platform

Rapid and EAsy Change detection in radar TIme-series by Variation coefficient

Foreword by Sentinel Hub

REACTIV Logo

1. Introduction: intents & motivation

Animation presenting the difference between an ephemerous and a permanent change in SAR Time Series

2. Context

Temporal Pixel definition
Acquisition timestamps

3. Script Description

HSV Cylinder — SharkDderivative work: SharkD Talk — HSV_color_solid_cylinder.png, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=9801673

3.1 Hue component: time dimension

Hue component formula for a pixel of coordinates (i,j)
Hue value selection animation

3.2 Saturation component: change intensity

Saturation component formula for a pixel of coordinates (i,j)

3.3 Value Component: SAR signal intensity

Value component formula for a pixel of coordinates (i,j)
Value component calculation

4. Application examples

4.1 Maritime Routes: Shanghai Port

Shanghai port displayed using REACTIV on acquistions ranging from 2018–01–01 to 2020–09–11

4.2 Vegetation monitoring: Shanghai Wetlands

Shanghai Wetlands displayed using REACTIV on acquistions ranging from 2018–01–01 to 2020–09–11

4.3 Urban sprawl: Wuhan City

Wuhan City displayed using REACTIV on acquistions ranging from 2018–01–01 to 2020–09–11
Zoomed REACTIV image of Wuhan displaying the newly built Huoshenshan Hospital

5. Conclusion

6. References & Credits

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Stories from the next generation satellite imagery platform

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Thomas Di Martino

As a French PhD student, I am passionate to whatever comes close to Artificial Intelligence and Earth Observation.