Week 13 · Remote Sensing Specialist~7 min · 592 words

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

GOES-18 sits directly south of the Hawaiian Islands at the equator (137.0°W). Its full-disk view sees Hawaiʻi, the US West Coast, and most of the Pacific in every frame.

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

SatellitePositionRole
GOES-16drifted to 105W (stowed)Backup
GOES-18137.0°WGOES-West operational
GOES-1975.2°WGOES-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:

  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.

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 Datas3://noaa-goes16, s3://noaa-goes17, s3://noaa-goes18, s3://noaa-goes19. Anonymous (--no-sign-request) reads, region us-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 Datasetsgs://gcp-public-data-goes-16 through -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.

RealEarth at NOAA STAR shows live GOES-18 imagery. Bookmark it. Watch a Pacific storm spiral in real time.

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.

Q1. GOES-R ABI has how many bands?
  1. 8
  2. 12
  3. 16
  4. 20
Q2. Mesoscale mode covers approximately:
  1. Full Earth disk
  2. Continental US
  3. 1000 km x 1000 km
  4. Polar regions
Q3. GOES-19 is the:
  1. GOES-East operational satellite (75.2W)
  2. GOES-West operational satellite (137.0W)
  3. Test satellite only
  4. Retired
Q4. Mesoscale refresh interval is:
  1. 30 seconds
  2. 5 minutes
  3. 15 minutes
  4. 1 hour
Q5. GOES is in:
  1. LEO
  2. MEO
  3. GEO
  4. Polar

Reflection

Take five minutes with this. Write your answer somewhere. Carry it into next week.

What does it mean that 'a satellite watches Hawaiʻi'? Is it watching FOR us — for hurricane warning, for fire detection — or watching us? When is the difference important?
Mark this week complete Visiting alone doesn't count it as 'done'. Click when you've actually worked through the primer + lab + quiz.
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