Landsat-8¶

Overview¶

Landsat-8 is part of the Landsat program jointly operated by NASA and the USGS. It carries two instruments: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS), which together provide multispectral and thermal imagery for land monitoring. With a spatial resolution of 30 meters for most bands and a 16-day revisit cycle, Landsat-8 is widely used for vegetation analysis, land cover classification, and environmental monitoring.

In GeeFetch, Landsat-8 data is accessed via the Google Earth Engine collection LANDSAT/LC08/C02/T1_L2, which provides Collection 2, Tier 1 Level-2 surface reflectance and surface temperature products.

Processing¶

Filtering by date range and area of interest
Cloud and saturated pixels masking using the QA_PIXEL and QA_RADSAT bands.
Bidirectional Reflectance Distribution Function (BRDF) correction: adjust radiometric values to account for variations in surface reflectance based on the sun and view angles.
Resampling to target resolution
Mosaicking of overlapping acquisitions
Scaling to maximize precision with the requested data type. Pixels outside the range \((0, 65455)\) are saturated. For example, when the requested datatype is uint8, the image is scaled by \(255/2^{16}\).

Available Bands for download¶

Band	Description	Native resolution	Download by default
SR_B1	Band 1 (Ultra Blue, Coastal Aerosol, 0.435–0.451 µm)	30m	no
SR_B2	Band 2 (Blue, 0.452–0.512 µm)	30m	yes
SR_B3	Band 3 (Green, 0.533–0.590 µm)	30m	yes
SR_B4	Band 4 (Red, 0.636–0.673 µm)	30m	yes
SR_B5	Band 5 (Near-Infrared, 0.851–0.879 µm)	30m	yes
SR_B6	Band 6 (Shortwave Infrared 1, 1.566–1.651 µm)	30m	yes
SR_B7	Band 7 (Shortwave Infrared 2, 2.107–2.294 µm)	30m	yes

Refer to LANDSAT/LC08/C02/T1_L2 for more details.

Configuration Options¶

See common configuration options.

Example Usage¶

Command Line¶

Write the following config.yaml

data_dir: ~/satellite_data
satellite_default:
  aoi:
    spatial:
      left: 2.2
      bottom: 48.7
      right: 2.5
      top: 49
      epsg: 4326
    temporal:
      start_date: "2023-06-01"
      end_date: "2023-06-30"
  gee:
    ee_project_ids: ["your-gee-id"]
  tile_size: 2000
  resolution: 10

then download with

geefetch landsat8 -c config.yaml

Python API¶

Though this is not geefetch main intended use, you can bypass the configuration and directly download Landsat-8 data with the geefetch.data.get.download_landsat8 function. For instance, the CLI command above is roughly equivalent to

import logging
from pathlib import Path

from geobbox import GeoBoundingBox

from geefetch.data.get import download_landsat8
from geefetch.utils.gee import auth
from geefetch.utils.log import setup

setup(level=logging.INFO)

data_dir = Path("geefetch_data/")
data_dir.mkdir(exist_ok=True)

auth("your-gee-id")

download_landsat8(
    data_dir,
    bbox=GeoBoundingBox(2.2, 48.7, 2.5, 49),
    start_date="2023-06-01",
    end_date="2023-06-30",
    tile_shape=2000,
)

See the API reference of geefetch.data.get.download_landsat8 for more details.

Relevant library code¶

Landsat8
geefetch.data.get.download_landsat8