mirror of
https://github.com/smittix/intercept.git
synced 2026-07-06 08:38:14 -07:00
James Smith
96172ca593
First-time run of ruff-format via pre-commit hook normalises quote style, trailing commas, and whitespace across 188 Python files. No logic changes. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
99 lines
3.1 KiB
Python
99 lines
3.1 KiB
Python
"""SSTV protocol constants.
|
|
|
|
VIS (Vertical Interval Signaling) codes, frequency assignments, and timing
|
|
constants for all supported SSTV modes per the SSTV protocol specification.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# Audio / DSP
|
|
# ---------------------------------------------------------------------------
|
|
SAMPLE_RATE = 48000 # Hz - standard audio sample rate used by rtl_fm
|
|
|
|
# Window size for Goertzel tone detection (5 ms at 48 kHz = 240 samples)
|
|
GOERTZEL_WINDOW = 240
|
|
|
|
# Chunk size for reading from rtl_fm (100 ms = 4800 samples)
|
|
STREAM_CHUNK_SAMPLES = 4800
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# SSTV tone frequencies (Hz)
|
|
# ---------------------------------------------------------------------------
|
|
FREQ_VIS_BIT_1 = 1100 # VIS logic 1
|
|
FREQ_SYNC = 1200 # Horizontal sync pulse
|
|
FREQ_VIS_BIT_0 = 1300 # VIS logic 0
|
|
FREQ_BREAK = 1200 # Break tone in VIS header (same as sync)
|
|
FREQ_LEADER = 1900 # Leader / calibration tone
|
|
FREQ_BLACK = 1500 # Black level
|
|
FREQ_WHITE = 2300 # White level
|
|
|
|
# Pixel luminance mapping range
|
|
FREQ_PIXEL_LOW = 1500 # 0 luminance
|
|
FREQ_PIXEL_HIGH = 2300 # 255 luminance
|
|
|
|
# Frequency tolerance for tone detection (Hz)
|
|
FREQ_TOLERANCE = 50
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# VIS header timing (seconds)
|
|
# ---------------------------------------------------------------------------
|
|
VIS_LEADER_MIN = 0.200 # Minimum leader tone duration
|
|
VIS_LEADER_MAX = 0.500 # Maximum leader tone duration
|
|
VIS_LEADER_NOMINAL = 0.300 # Nominal leader tone duration
|
|
VIS_BREAK_DURATION = 0.010 # Break pulse duration (10 ms)
|
|
VIS_BIT_DURATION = 0.030 # Each VIS data bit (30 ms)
|
|
VIS_START_BIT_DURATION = 0.030 # Start bit (30 ms)
|
|
VIS_STOP_BIT_DURATION = 0.030 # Stop bit (30 ms)
|
|
|
|
# Timing tolerance for VIS detection
|
|
VIS_TIMING_TOLERANCE = 0.5 # 50% tolerance on durations
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# VIS code → mode name mapping
|
|
# ---------------------------------------------------------------------------
|
|
VIS_CODES: dict[int, str] = {
|
|
8: "Robot36",
|
|
12: "Robot72",
|
|
44: "Martin1",
|
|
40: "Martin2",
|
|
60: "Scottie1",
|
|
56: "Scottie2",
|
|
95: "PD120",
|
|
97: "PD180",
|
|
# Less common but recognized
|
|
4: "Robot24",
|
|
36: "Martin3",
|
|
52: "Scottie3",
|
|
76: "ScottieDX",
|
|
96: "PD240",
|
|
99: "PD90",
|
|
98: "PD160",
|
|
}
|
|
|
|
# Reverse mapping: mode name → VIS code
|
|
MODE_TO_VIS: dict[str, int] = {v: k for k, v in VIS_CODES.items()}
|
|
|
|
# ---------------------------------------------------------------------------
|
|
# Common SSTV modes list (for UI / status)
|
|
# ---------------------------------------------------------------------------
|
|
SSTV_MODES = [
|
|
"PD120",
|
|
"PD180",
|
|
"Martin1",
|
|
"Martin2",
|
|
"Scottie1",
|
|
"Scottie2",
|
|
"Robot36",
|
|
"Robot72",
|
|
]
|
|
|
|
# ISS SSTV frequency
|
|
ISS_SSTV_FREQ = 145.800 # MHz
|
|
|
|
# Speed of light in m/s
|
|
SPEED_OF_LIGHT = 299_792_458
|
|
|
|
# Minimum energy ratio for valid tone detection (vs noise floor)
|
|
MIN_ENERGY_RATIO = 5.0
|