GOES-R ABI: full-disk, CONUS, mesoscale
GOES-R (GOES-16/17/18/19) revolutionized geostationary weather imagery. 16 bands, refresh as fast as 30 seconds (mesoscale), and the data is free. This is the sensor LaunchDetect uses in production.
GOES-18 (the GOES-West satellite) is in geostationary orbit at 137.0°W. That is the satellite watching Hawaiʻi right now. Have you ever seen its imagery?
GOES-18 looks down at Hawaiʻi 24 hours a day. Its imagery refreshes every 30 seconds during severe weather. The same satellite watches Pacific hurricanes — and would see a Kīlauea eruption plume, or a rocket launch from PMRF.
Learning objectives
- List the 16 ABI bands and what each is used for
- Distinguish full-disk, CONUS, and mesoscale scanning modes
- Read a GOES-R ABI NetCDF file with xarray + satpy
- Explain why GOES is fixed at GEO and what that means for resolution
Primer
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
| Satellite | Position | Role |
|---|---|---|
| GOES-16 | drifted to 105W (stowed) | Backup |
| GOES-18 | 137.0°W | GOES-West operational |
| GOES-19 | 75.2°W | GOES-East operational (since 2025) |
The Americas + Atlantic are covered by GOES-19 (East); the Pacific + western US + Hawaiʻi 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:
- 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.
- CONUS / FullDisk Sectors — fixed sector covering the contiguous United States, every 5 minutes.
- 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.
Where the data lives
GOES-R imagery is one of the few satellite archives that ships live from a public cloud bucket — no login, no rate limit, no quota:
- NOAA AWS Open Data —
s3://noaa-goes16,s3://noaa-goes17,s3://noaa-goes18,s3://noaa-goes19. Anonymous (--no-sign-request) reads, regionus-east-1. New scenes land ~30 seconds after acquisition. Path structure:<Product>/<Year>/<DOY>/<Hour>/OR_ABI-...-M6C07_G18_s<start>_e<end>_c<create>.nc. DOY is day-of-year (001-366). For mesoscale 1 Band 7 on 2026-05-12 at 18:00 UTC:ABI-L1b-RadM/2026/132/18/OR_ABI-L1b-RadM1-M6C07_G18_*.nc. - Google Cloud Public Datasets —
gs://gcp-public-data-goes-16through-19. Mirror of the same NOAA archive, useful if your compute is on GCP. - NOAA CLASS (
www.aev.class.noaa.gov) — official NOAA archive UI with full historical backfill. Slower than S3 but covers gaps before AWS coverage began (2017 onward). - Himawari-9 (JMA, 140.7°E) — for the western Pacific. AWS Open Data at
s3://noaa-himawari9. Same NetCDF-ish shape with HSD (Himawari Standard Data) raw format also available. We'll use it in Week 21 for multi-sensor fusion.
For Python, the path of least resistance: s3fs.S3FileSystem(anon=True).glob(...) to discover files, then either xarray.open_dataset with the fsspec backend (streams) or aws s3 cp ... --no-sign-request if you want a local copy. The whole-archive size is petabytes; you almost never want to download all of it. The lab pulls a single ~3 MB mesoscale scene.
The lab
You'll pull a real GOES-18 Band 7 mesoscale scene from s3://noaa-goes18 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.
Connecting to Hawaiʻi: GOES-West watches Hawaiʻi
Of the three geostationary satellites in the GOES-R series, GOES-18 (West, 137.0°W) is the one stationed directly over the eastern Pacific to watch Hawaiʻi, the US West Coast, and Pacific weather systems. NOAA's Central Pacific Hurricane Center in Honolulu uses GOES-18 imagery every hour to track tropical systems that could become Hawaiian hurricanes. The Hawaiʻi Volcano Observatory has used GOES-18 thermal infrared imagery to monitor Kīlauea eruptions. This is YOUR satellite. The lab this week opens a real GOES-18 file.
Hands-on lab: Open a GOES-18 ABI Band 7 mesoscale scene
Download a real GOES-18 Band 7 mesoscale NetCDF from the NOAA public AWS bucket. Open it with satpy. Plot it. Identify the geographic coverage area.
Quiz — click an answer to check it
No grade, no shame. Tap any option; you'll see if it's right plus the answer if not. The point is to notice what you already know and what's still settling.
- 8
- 12
- 16
- 20
- Full Earth disk
- Continental US
- 1000 km x 1000 km
- Polar regions
- GOES-East operational satellite (75.2W)
- GOES-West operational satellite (137.0W)
- Test satellite only
- Retired
- 30 seconds
- 5 minutes
- 15 minutes
- 1 hour
- LEO
- MEO
- GEO
- Polar
Reflection
Take five minutes with this. Write your answer somewhere. Carry it into next week.