methane_index

Computes methane index from ultra emitters for a region and date range. The workflow retrieves the relevant Sentinel-2 products with Planetary Computer (PC) API and crop the rasters for the region defined in user_input. All bands are normalized and an anti-aliasing guassian filter is applied to smooth and remove potential artifacts. An unsupervised K-Nearest Neighbor is applied to identify bands similar to band 12, and the index is computed by the difference between band 12 to the pixel-wise median of top K similar bands.

graph TD inp1>user_input] out1>index] out2>s2_raster] out3>cloud_mask] tsk1{{s2}} tsk2{{clip}} tsk3{{methane}} tsk1{{s2}} -- raster --> tsk2{{clip}} tsk2{{clip}} -- clipped_raster/raster --> tsk3{{methane}} inp1>user_input] -- user_input --> tsk1{{s2}} inp1>user_input] -- input_geometry --> tsk2{{clip}} tsk3{{methane}} -- index_raster --> out1>index] tsk1{{s2}} -- raster --> out2>s2_raster] tsk1{{s2}} -- mask --> out3>cloud_mask]

Sources

user_input: Time range and geometry of interest.

Sinks

index: Methane index raster.
s2_raster: Sentinel-2 raster.
cloud_mask: Cloud mask.

Parameters

pc_key: Optional Planetary Computer API key.

Tasks

s2: Downloads and preprocesses Sentinel-2 imagery that covers the input geometry and time range, and computes improved cloud masks using cloud and shadow segmentation models.
clip: Performs a clip on an input raster based on a provided reference geometry.
methane: Computes an index from the bands of an input raster.

Workflow Yaml

name: methane_index
sources:
  user_input:
  - s2.user_input
  - clip.input_geometry
sinks:
  index: methane.index_raster
  s2_raster: s2.raster
  cloud_mask: s2.mask
parameters:
  pc_key: null
tasks:
  s2:
    workflow: data_ingestion/sentinel2/preprocess_s2_improved_masks
    parameters:
      pc_key: '@from(pc_key)'
  clip:
    workflow: data_processing/clip/clip
  methane:
    workflow: data_processing/index/index
    parameters:
      index: methane
edges:
- origin: s2.raster
  destination:
  - clip.raster
- origin: clip.clipped_raster
  destination:
  - methane.raster
description:
  short_description: Computes methane index from ultra emitters for a region and date
    range.
  long_description: The workflow retrieves the relevant Sentinel-2 products with Planetary
    Computer (PC) API and crop the rasters for the region defined in user_input. All
    bands are normalized and an anti-aliasing guassian filter is applied to smooth
    and remove potential artifacts. An unsupervised K-Nearest Neighbor is applied
    to identify bands similar to band 12, and the index is computed by the difference
    between band 12 to the pixel-wise median of top K similar bands.
  sources:
    user_input: Time range and geometry of interest.
  sinks:
    index: Methane index raster.
    s2_raster: Sentinel-2 raster.
    cloud_mask: Cloud mask.
  parameters:
    pc_key: Optional Planetary Computer API key.