InmarScope

# InmarScope

### Decode the satellites. Follow the voice.

**InmarScope** is a next‑generation L‑band satellite decoder for the desktop — one application that turns an inexpensive SDR into a full Inmarsat monitoring station for **aeronautical (Aero)** and **maritime (Inmarsat‑C / EGC)** traffic alike. Live spectrum, multi‑channel decoding, voice, and structured data output, all in a single, fast, native window.

If you've used JAERO or Scytale‑C, think of InmarScope as both of them — unified, modernized, and built around a feature neither of them has: **automatic voice‑call following.**

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## Voice‑Follow

C‑channel voice calls hop around the band. **InmarScope chases them for you.** The moment a voice‑channel assignment is broadcast, InmarScope retunes, locks the carrier, and decodes the call — then returns to where it was when the call ends. No babysitting, no manual retuning.

- **One‑SDR mode** — hops to the assigned voice frequency, decodes the call, and hops back to your P‑channel automatically.
- **Two‑SDR mode** — dedicate a second RTL‑SDR to voice. One radio stays glued to the P‑channel while the other follows every call, with a **live split‑view spectrum and waterfall** so you watch it pounce in real time.
- **Auto‑nudge AFC**, lock‑based hold timing, and **automatic per‑call recording** — every conversation saved to its own WAV, whether or not you're listening.

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## Decode everything

InmarScope runs **many channels at once** through a shared channelizer and a multi‑threaded worker pool — stack P‑channel, R‑channel, voice, and Inmarsat‑C decoders side by side.

| Mode | Rate | What you get |
|------|------|--------------|
| **Aero MSK** | 600 / 1200 bps | ACARS messages, signal units, C‑channel assignments, network & satellite ID |
| **Aero OQPSK** | 10500 bps | High‑rate forward‑link ACARS, call announcements, system tables |
| **Aero Voice (OQPSK)** | 8400 bps | AMBE voice decode + live playback + per‑call recording |
| **Inmarsat‑C / EGC** | 1200 sym/s BPSK | SafetyNET & FleetNET broadcasts, NAVAREA/METAREA warnings, system messages, bulletin board (frame # + UTC) |

Decoded traffic lands in clean, dedicated views: **Messages** (parsed ACARS), **SUs**, **C‑Channel** assignments, **Network** (auto‑discovered channels & satellite longitude), and **EGC** (maritime safety messages) — each with the registration, label, priority, service, and message text laid out for you.

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## See the whole band

- **Aligned spectrum + waterfall** that track each other frequency‑for‑frequency at any zoom.
- **Band browsing** — pan or scroll past the edge of the capture and InmarScope retunes the radio to follow, so you can sweep the entire band without fiddling with center frequency.
- **FFTs up to 65,536 points** for razor‑sharp resolution — perfect for spotting that thin, always‑on Inmarsat‑C carrier.
- **Click‑to‑decode** — Ctrl‑click anywhere on the spectrum to drop a decoder, drag the marker to fine‑tune, and watch the constellation snap into lock.

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## Bring any radio

- **RTL‑SDR** — native, with independent **bias‑tee** control.
- **HackRF** — native libhackrf support with full LNA / VGA / amp / antenna‑power control.
- **SDR++ Server** — connect over the network and even **change the server's sample rate remotely**.
- **WAV IQ playback** — replay your captures and decode them offline.

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## Share your data

InmarScope speaks the formats the community already uses:

- **JSON** — JAERO JSONdump schema (drop straight into **Acarshub**) for ACARS, and the inmarsat‑sniffer STD‑C schema for EGC.
- **JAERO text** format for classic human‑readable logs.
- Stream to a **file** or push over **UDP** to your own pipeline, dashboard, or aggregator.

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## Built for real use

- Fast, native Windows application — a single clean GUI window, no console clutter.
- Multi‑threaded, multi‑channel, low‑drop decoding.
- Voice playback through your speakers; recordings organized by frequency and timestamp.
- Built‑in update notifications so you're always on the latest build.

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## Who it's for

Aviation and maritime radio enthusiasts, SIGINT hobbyists, safety‑traffic watchers, and SDR tinkerers who want **one tool** that does Aero *and* Inmarsat‑C — and actually **follows the voice.**