signalark

GNSS signal data collection pipeline. Connects to a u-blox receiver, captures raw UBX binary, and outputs structured CSVs for downstream analysis.

Built on go-ubx.

Features

• Raw UBX binary recording with auto-generated timestamped filenames
• File rotation (-rotate 1h for hourly splits)
• Structured CSV output for NAV-PVT, NAV-SAT, NAV-SIG, MON-RF, RXM-RAWX, RXM-SFRBX
• Configurable message selection (-messages flag)
• Session labels for ML training data (-mobility, -skyvis, -weather, -anomaly)
• Auto-recorded start position (lat/lon from first NAV-PVT fix)
• Periodic status display (epochs, fix rate, CN0, file size every 10s)
• Periodic flush (CSV + raw binary every 10s to minimize data loss)
• Write error logging with running count
• Metadata recording (metadata.json)
• Serial port auto-detection (Linux /dev/ttyACM*, macOS /dev/cu.usbmodem*)
• Receiver auto-configuration (enables selected UBX messages via CFG-VALSET)

Usage

# Static observation, open sky
signalark -dir ./collect/session_001 -csv \
  -mobility static -skyvis open \
  -antenna patch -notes "Seya Park, clear sky, tripod"

# Walking in urban area
signalark -dir ./collect/session_002 -csv \
  -mobility walk -skyvis urban \
  -antenna patch -notes "Yokohama Station west exit"

# Driving with roof antenna
signalark -dir ./collect/session_003 -csv \
  -mobility drive -skyvis open \
  -antenna magnet_roof -notes "Hodogaya Bypass"

# Simple raw capture (no session labels)
signalark -port /dev/ttyACM0 -out capture.ubx

# Auto-detect port, 10Hz, quiet mode
signalark -dir ./collect -csv -rate 100 -quiet

Output Structure

When using -dir, signalark creates:

session_001/
├── raw/
│   ├── gnss_20260407_120000.ubx   # Raw binary (rotated if -rotate set)
│   └── gnss_20260407_130000.ubx
├── parsed/
│   ├── nav_pvt.csv                # Position, velocity, time
│   ├── nav_sat.csv                # Per-satellite elevation, azimuth, CN0
│   ├── nav_sig.csv                # Per-signal quality and health
│   ├── mon_rf.csv                 # RF/jamming indicators
│   ├── rxm_rawx.csv              # Raw measurements
│   ├── rxm_sfrbx.csv             # Navigation subframe data
│   └── gaps.csv                   # Data gap log (if gaps detected)
└── metadata.json                  # Collection conditions + session labels

Flags

Flag	Default	Description
-port	auto-detect	Serial port path
-baud	115200	Baud rate
-rate	1000	Measurement interval (ms)
-dir		Output directory (enables structured output)
-out		Raw file path (mutually exclusive with -dir)
-csv	false	Enable CSV output (requires -dir)
-rotate		File rotation interval (e.g., 1h, 30m)
-quiet	false	Suppress console output
-antenna		Antenna description
-mobility		Mobility mode: static, walk, drive
-skyvis		Sky visibility: open, suburban, urban, canyon, indoor, tunnel
-weather		Weather: clear, cloudy, rain, snow
-anomaly	normal	Anomaly label: normal, spoofing, jamming
-messages	nav-pvt,nav-sat,nav-sig,mon-rf,rxm-rawx,rxm-sfrbx	Comma-separated UBX messages to enable
-notes		Free-form notes (location name, conditions, etc.)

Install

go install github.com/keitaj/signalark@latest

License

MIT