GOES-R ABI: full-disk, CONUS, mesoscale

The GOES-R series (GOES-16, 17, 18, 19) is NOAA's flagship geostationary weather constellation. From 35,786 km altitude over the equator, each satellite stares continuously at one hemisphere of Earth, producing the highest-cadence operational Earth imagery available to the public — including the 30-second mesoscale refresh that LaunchDetect uses for real-time launch detection.

The GOES-R fleet

The Americas + Atlantic are covered by GOES-19 (East); the Pacific + western US + Hawaii by GOES-18 (West). Combined, they cover from longitude ~160°E to ~10°W. Outside that range, the geometry is too oblique to be useful — that's where JMA Himawari-9 takes over (East Asia and Western Pacific).

The ABI sensor

The Advanced Baseline Imager (ABI) is the primary instrument on every GOES-R satellite. It has 16 spectral bands:

• Bands 1–2 (visible, 0.47 and 0.64 µm) — for clouds, daytime imagery. Band 2 is the "red" channel used in true-color composites.
• Band 3 (veggie, 0.86 µm) — vegetation and aerosol.
• Bands 4–6 (cirrus + SWIR, 1.37–2.24 µm) — thin cirrus, cloud-particle size, snow/ice discrimination.
• Band 7 (shortwave window, 3.9 µm) — the workhorse for thermal hotspot detection. Sensitive to fires, plumes, gas flares, hot industrial sources. The band LaunchDetect uses.
• Bands 8–10 (water vapor, 6.2, 6.9, 7.3 µm) — upper, mid, lower troposphere water vapor.
• Bands 11–13 (longwave window, 8.4, 9.6, 10.3 µm) — cloud-top phase, ozone, "clean" thermal IR.
• Bands 14–15 (longwave window, 11.2, 12.3 µm) — "dirty" thermal IR pair, used for split-window SST retrieval.
• Band 16 (CO₂ longwave, 13.3 µm) — cloud-top temperature, CO₂ absorption.

Three scanning modes

ABI scans Earth in three nested modes simultaneously:

1. Full Disk — the entire Earth hemisphere, every 10 minutes (in Mode 6, current standard). Resolution: 2 km for Band 7 (and most others); 0.5 km for Band 2.
2. CONUS / FullDisk Sectors — fixed sector covering the contiguous United States, every 5 minutes.
3. Mesoscale 1 & 2 — two operator-controllable 1,000 × 1,000 km windows, every 30 seconds. Each mesoscale window is moved by NOAA operators to focus on active weather events — hurricanes, severe convection, and (when an operator agrees to cooperate) active launches.

The 30-second mesoscale cadence is what makes real-time launch detection possible. A Falcon 9 ascent from Vandenberg passes through several mesoscale frames during boost phase; LaunchDetect captures the plume in each.

The data

Every ABI scene is published as a NetCDF file to NOAA's public AWS Open Data bucket within seconds of generation:

s3://noaa-goes18/ABI-L1b-RadM/{year}/{day-of-year}/{hour}/{filename}.nc

For Band 7, mesoscale 1: OR_ABI-L1b-RadM1-M6C07_G18_*.nc. The file is ~3 MB per scene. Open with xarray, netCDF4, or — most conveniently — the satpy library which handles georeferencing automatically.

The lab

You'll download a real GOES-18 Band 7 mesoscale scene over the Pacific, open it with satpy, plot it on a map with proper geographic coordinates (handled via Scene.resample()), and identify the geographic coverage area. By the end you'll understand the data shape, units, and georeferencing — preparation for Week 14 where the same data is used for actual plume detection.