---
name: pwn-sdr-decoder-apt
description: Drive PWN::SDR::Decoder::APT from pwn_eval.
license: MIT
allowed-tools: [pwn, pwn_eval]
metadata:
bundled: true
generated: true
module: PWN::SDR::Decoder::APT
source: pwn/sdr/decoder/apt.rb
---
# PWN::SDR::Decoder::APT
Pure-Ruby NOAA APT (Automatic Picture Transmission) decoder for the 137 MHz polar-orbiting weather satellites (NOAA-15/18/19). APT is a 2400 Hz AM subcarrier inside a ~34 kHz-wide FM downlink carrying two 909-pixel image channels at 2 lines/second (2080 words/line). This module envelope-demodulates the 2400 Hz carrier from audio, resamples to 4160 words/sec with continuous phase, and aligns the initial line on a Sync-A correlation candidate. Fixed-rate rows update a bounded rolling P5 PGM; there is no drift tracking or satellite identification. Line contrast is normalized independently. No `sox`, no `noaa-apt`.
## When to use
Call `PWN::SDR::Decoder::APT` from `pwn_eval` when the task needs this module.
Do not reimplement it in shell.
## Methodologies
Generated from `pwn/sdr/decoder/apt.rb`. Prefer the public class methods below.
Class methods take `(opts = {})` and read `opts`.
## How to call
```ruby
PWN::SDR::Decoder::APT.help
PWN::SDR::Decoder::APT.detect(opts)
```
## Public methods
- `detect`
- `decode`
- `authors`
- `help`
## Source
`pwn/sdr/decoder/apt.rb`
## Verification
`PWN::SDR::Decoder::APT.respond_to?(:detect)` after the
module is loaded. Read the source for parameter names.
