ALOS Kyoto & Carbon Mosaics by JAXA

This module have been designed on top of the interactive framework sepal_ui. it allows the user to extract ALOS K&C mosaics. The input are as simple as: an AOI, a year, and some filters. The user will be able to display the mosaic in an interactive map and export it as a GEE asset and/or a sepal Tif file.

This module is a sepalization of the follwing script by A. Vollrath`_.

The process is done in 3 steps described in the bellow sections and presented in the bellow video tutorial:

Select an AOI

Using the provided AOI selector, select an AOI of your choice between the different methods available in the tool. We provide 3 administration descriptions (from level 0 to 2) and 3 custom shapes (drawn directly on the map, asset or shapefile).

https://raw.githubusercontent.com/lecrabe/alos_mosaics/main/doc/img/aoi_select.png

aoi selector

Note

If a custom aoi from shape or drawing is selected, you will be able to use it directly and the upload to GEE will be launched in the background

Process mosaic

Then in the process tile, you need to set the different parameters of your mosaic:

  • year: The year of interest

  • speckle filter: the speckle filter to use during the process

  • shadow masking: activate or deactivate the shadow masking

  • Db: wether or not to scale the output to Db

Once you are happy with your parameters, you can click on the button. The dataset will be automatically send to the vizualization tile.

https://raw.githubusercontent.com/lecrabe/alos_mosaics/main/doc/img/parameters.png

dataset parameters

Display dataset

As mentioned in the above section, the dataset is automatically displayed on the map. THis map is interactive allowing you to zoom in and out. Note that you can select betwee 3 diplay options:

  • Backscatter RGB (HH, HV, HH/HV power ratio)

  • Radar Forest Degradation Index (RFDI, Mitchard et al. 2012)

  • Forest/Non-Forest

https://raw.githubusercontent.com/lecrabe/alos_mosaics/main/doc/img/display.png

display informations

Export dataset

Once you’re happy with the information displayed then can be exported to be further used in a GIS software or in a GEE process. The tool provide 2 main exportation options, as an asset(in GEE) or as a Tif file in SEPAL.

Both use the GEE export system and share the same set of parameter:

  • Export Backscatter (HH, HV, HH/HV power ratio)

  • Export/Add Radar Forest Degradation Index (RFDI, Mitchard et al. 2012)

  • Export/Add GLCM texture layers for HH and HV polarizations (Variance, Homogeneity, Dissimilarity)

  • Export/Add auxiliary metadata layers (Acq. Date, LIA, QA layer)

  • Export K&C Forest/Non-Forest map (separate file)

  • set the resolution as an integer number

Note

The default export parameter are 25 meters resolution with backscatter and RFDI

https://raw.githubusercontent.com/lecrabe/alos_mosaics/main/doc/img/export.png

export

Danger

When the image is exported to SEPAL, you cannot quit the application until the downloading is finished.