Earth Data School
About
Full catalog/sentinel-1-etad
sentinel-1-etad·dataset

Timing corrections that sharpen Sentinel-1 radar maps

Sentinel-1 Extended Time Annotation Products (ETAD)
land ESA ESA Copernicus active
In plain English

What it measures. These are not pictures but correction layers that pinpoint and adjust tiny timing and positioning errors in Sentinel-1 radar data, caused by the atmosphere, Earth tides, and the radar system itself.

How it's made. Provided by ESA Copernicus as auxiliary files for the Sentinel-1 radar mission, delivered in NetCDF format with multiple correction layers to be applied to the raw radar acquisitions.

How & where you'd use it. This is a technical input, not a standalone map: it helps specialists place Sentinel-1 radar imagery on the ground with much greater geometric accuracy, important for precise change and deformation measurements.

What's measured

SentinelCopernicusESAETADSARC-BandEUECIWEWSM

Coverage & cadence

  • Time span2023-07-21 → ongoing
  • Spatial extent-180, -90, 180, 90

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

This collection provides Sentinel-1 Extended Time Annotation Products (ETAD), auxiliary datasets designed to improve the geometric accuracy of Sentinel-1 SAR products. ETAD products contain multiple timing correction layers that can be applied to Sentinel-1 Interferometric Wide Swath (IW), Strip Map (SM), and Extra Wide Swath (EW) acquisitions. The data are distributed in NetCDF format and include corrections for ionospheric and tropospheric delays, solid Earth tides, and system timing effects such as Doppler shifts, bi-static corrections, and height-dependent FM-rate mismatches.

Get the data

copernicus_access.py
# ESA Copernicus Data Space — open STAC API (free account)
from pystac_client import Client

cat = Client.open("https://stac.dataspace.copernicus.eu/v1")
search = cat.search(
    collections=["sentinel-1-etad"],   # add _cog or _nc for a format variant
    bbox=(-10, 35, 30, 60),             # your area (W,S,E,N)
    datetime="2024-01-01/2024-12-31",
)
items = list(search.items())            # then read assets with rioxarray / xarray
Browsing the Copernicus STAC is open; downloading bytes needs a free Copernicus Data Space account.