Interpreting SAR data for forest monitoring

Radar remote sensing for forest monitoring in Google Earth Engine

Africa I. Flores-Anderson 19-05-2023

Learning objectives:

• Visualize and interpret deforestation events using Sentinel-1 and Alos Palsar data in GEE
• Plot time series data from Sentinel-1 and Alos Palsar and explain changes in forest cover
• Distinguish how SAR C-band and L-band see deforestation events

Using Google Earth Engine

1. Open the code editor of GEE
2. The following figure describes the GEE code editor interface

_{Figure 1. GEE User Interface.}

Location of Interest

We will explore a deforestation event in Papau New Guinea as detected by RADD Forest Disturbance Alert. The location of interest is Lat: -4.011° , Lon: 141.303°. Below we can see a detailed time series of this location using Planet data. A main deforestation event is first visible on April 2022.

_{Figure 2. Time series of location of interest in optical data .}

We will explore in the following exercises how this event is seen by radar data, both Sentinel-1 and Alos Palsar.

Exercises:

1. Time series visualization Sentinel-1 and Alos Palsar
2. Plotting Time series values and calculation of Vegetation Indices from Sentinel-1 and Alos Palsar