forge-py

The Footprint Generator project provides tools for generating geographic footprints from various data sources. This tool supports different generation strategies using open cv or alpha shape.

Installation

Using pip:

pip install forge-py

Using poetry:

poetry install

CLI Usage

forge-py -c configuration_file.cfg -g granule_file.nc

The forge-py command-line tool accepts the following options:

• -c, --config: (Optional) Specifies the path to the configuration file. This file contains parameters for customizing the footprint generation process.

• -g, --granule: (Required) Specifies the path to the data granule file. This file contains the raw data used to generate the footprints.

Footprint Configuration

The configuration file specifies the parameters for generating footprints from various data sources, primarily using OpenCV and Alpha Shape algorithms.

Configuration Options

footprint

• lonVar (string, required): Longitude variable in the dataset include group if in one.

• latVar (string, required): Latitude variable in the dataset include group if in one.

• is360 (boolean, optional, default: False): Indicates if the data is in 360 format.

• strategy (optional, default: alpha_shape):

  • open_cv: Uses OpenCV-based image processing techniques to extract footprints.
  • alpha_shape: Employs the Alpha Shape algorithm to construct footprints from point data.

• open_cv:

  • pixel_height (int, optional, default: 1800): Desired pixel height for the input image.
  • min_area (int, optional): Minimum area for polygons to be retained.
  • fill_kernel (list of int, optional, default: [20,20]): Kernel size for filling holes in polygons.
  • simplify (float, optional,): Controls the level of simplification applied to extracted polygons.
  • fill_value (float, optional, default: np.nan): Fill value in the latitude, longitude arrays.

• alpha_shape:

  • alpha (float, optional, default: 0.05): Alpha value for the Alpha Shape algorithm, affecting the shape of polygons.
  • thinning (dic, optional):
    • method (string): Thinning method to apply to the Alpha Shape.
    • value (list of float or float): Thinning parameters.
  • cutoff_lat (int, optional): Latitude cutoff for smoothing.
  • min_area (int, optional): Minimum area for polygons to be retained.
  • smooth_poles (list of int, optional): Latitude range for smoothing near poles.
  • simplify (float, optional): Controls the level of simplification applied to extracted polygons.
  • fill_value (float, optional, default: np.nan): Fill value in the latitude, longitude arrays.

Example Configuration

   {
      "latVar":"group1/group2/lat",
      "lonVar":"group1/group2/lon",
      "timeVar":"time",
      "is360":false,
      "footprint":{
        "strategy": "open_cv",
        "open_cv": {
           "pixel_height": 1000,
           "simplify":0.3,
           "min_area": 30,
           "fill_value": -99999.0,
           "fill_kernel": [30,30]
        },
        "alpha_shape": {
           "alpha":0.2,
           "thinning": {"method": "bin_avg", "value": [0.5, 0.5]},
           "cutoff_lat": 80,
           "smooth_poles": [78,80],
           "simplify" : 0.3,
           "min_area": 30,
           "fill_value": -99999.0
        }
      }
    }