Weather Satellites & APT

satdump, WXtoImg, raspberry-noaa-v2 — decode NOAA APT, METEOR M, GOES HRIT from a $30 dongle.

The "magic" SDR project: receive a satellite passing overhead and watch a cloud-pattern image of your continent paint itself out of static. NOAA APT (137 MHz) and METEOR M (137 MHz LRPT) are the easy ones; GOES HRIT (1.69 GHz) and HimawariCast / FengYun need a dish but produce stunning full-disk imagery. Cross-link with SDR Receivers, Ham Satellite Tracking, and Pi Classic Projects.

All-in-one decoders

★ satdump — modern, cross-platform, decodes nearly every weather satellite in operation: NOAA APT, METEOR M N2-3 / N2-4 LRPT, GOES-16/17/18/19 HRIT/EMWIN, FengYun-3, Himawari HimawariCast (DVB-S2), Aqua / Terra / SNPP / NOAA-20 X-band HRPT, Elektro-L, Meteor-MN, Iridium, Inmarsat AERO, ATMS, AVHRR, MERSI-LL, NDPP, you name it. Active project, well-maintained, Apple Silicon native, replaces every legacy tool below. GPLv3. The 2026 default.
- https://github.com/SatDump/SatDump
WXtoImg — Windows / Mac / Linux; closed-source, freeware (last update ~2017; the developer's site is dead but mirrors and the registration key are widely available). NOAA APT-only; produces beautiful enhanced false-color products. Sunset; satdump replaces it.
NOAA-APT (Rust) — pure-Rust APT decoder; cleaner than WXtoImg for raw image extraction; no enhancement compositing. MIT.
GIS-friendly: gr-satellites — GNU Radio out-of-tree module by Daniel Estévez; decodes hundreds of cubesats and weather sats; the "research / cubesat ground station" choice. GPL.
- https://github.com/daniestevez/gr-satellites

Automated capture pipelines (Pi)

★ raspberry-noaa-v2 — Pi-based fully automated weather-satellite capture station. Uses orbital prediction (Predict / WXTrack) to schedule passes, records IQ, decodes via satdump or noaa-apt, generates web gallery, posts to Twitter/Mastodon. Supports NOAA APT and METEOR M. The 2026 standard "set it and forget it" station. GPLv3.
- https://github.com/jekhokie/raspberry-noaa-v2
Stigern's noaa-apt-station — alternative automated pipeline; lighter weight.
wxtrack-osx — Mac-only pass scheduler; sunset.

Pass scheduling / orbital prediction

★ Gpredict — see Ham Satellite Tracking — pass prediction, antenna control, frequency Doppler correction. GPL.
Predict / hamlib-utils — CLI-based orbital prediction; what raspberry-noaa-v2 uses underneath.
PstRotator — Windows; closed; satellite rotator control with Gpredict integration.

Hardware

★ RTL-SDR Blog v4 — works fine for 137 MHz NOAA / METEOR.
V-dipole antenna — two-pieces-of-coat-hanger 1/4-wave V at 137 MHz; the cheapest antenna that actually works for NOAA / METEOR overhead passes. ~$5 to build.
★ Quadrifilar Helix (QFH) / turnstile / Lindenblad — all-sky right-hand-circular-polarized antennas; 30–50% better than a V-dipole for low-elevation passes. Buy: Wimo, dxengineering, or build from PVC pipe + coax (instructions everywhere).
LNA at antenna — a 137 MHz LNA at the antenna feed makes a real difference; ~$25.
GOES dish — 1.2 m offset Ku/Ka dish + 1.69 GHz LNA + filter. ~$200 setup. Higher barrier; produces full-disk colorized cloud animations. Pinpoint to GOES-16 (US East) / GOES-18 (US West) / GOES-19 (post-launch successor) using a satellite tracker. GOES is geostationary so the dish is fixed once aligned.
2.4 GHz dish for HRPT (NOAA-18/19, MetOp-B/C, FengYun) — 1+ m parabolic, motorized rotator, 2.4 GHz LNA. Top-tier weather-sat hobby; satdump supports HRPT directly. ~$500–1000.

Practical guidance

NOAA APT is sunsetting. NOAA-15/18/19 are EOL; expected end of life late 2020s. METEOR M N2-3 and N2-4 are the live successor sats and produce sharper LRPT digital imagery on similar 137 MHz frequencies. Aim for METEOR if starting fresh.
Doppler shift. A LEO weather sat sweeps ±3 kHz across a pass. Most decoders auto-correct; for narrow APT (4 kHz subcarrier) it doesn't matter much, but for METEOR LRPT ensure your decoder's PLL handles it.
Polarization matters. NOAA/METEOR are right-hand-circular-polarized; a linear-pol antenna loses ~3 dB. QFH / turnstile / Lindenblad cure this.
Local interference. 137 MHz is between aviation VHF and the FM broadcast band. Filtering helps; LNA-at-antenna with FM-notch helps more.
Rain fade. GOES at 1.7 GHz is robust; HRPT at 2.4 GHz takes a hit in heavy rain.
Image enhancement. WXtoImg's "MCIR / sea surface temperature / multispectral" enhancements are why it persisted; satdump now matches all of them.

License / pricing notes

satdump / NOAA-APT / gr-satellites / raspberry-noaa-v2 / Gpredict — all FOSS (GPL).
WXtoImg — closed freeware; last release 2017; registration key is publicly circulated because the dev site is dead. Use satdump instead.
PstRotator — paid (~$45) for rotator integration.
No license required to receive weather satellites; their broadcasts are public unencrypted data.

Pick this if…

Default 2026 weather-sat decoder: satdump. Replace whatever else you were using.
Easiest first capture: RTL-SDR + V-dipole + satdump's NOAA APT live demodulator.
24/7 station with web gallery: raspberry-noaa-v2 on a Pi 4/5 + QFH antenna.
Best image quality from LEO: METEOR M N2-3/N2-4 LRPT (digital, sharper than APT).
Full-disk geostationary imagery: GOES HRIT/EMWIN with a 1.2 m dish + satdump.
Cubesat / research ground station: gr-satellites (GNU Radio OOT module).