Skybridge-Alaska

Operational Runbook — DOT-VHF Ground Station

Project: SkyBridge Alaska Station ID: DOT-VHF Date: 2026-03-12

1. Accessing the Station

SSH

ssh blastly@192.168.1.81        # Ethernet
ssh blastly@192.168.1.80        # WiFi (backup)

Key-only auth (Ed25519). No password login.
If locked out by fail2ban, wait 1 hour or access via physical console.

Web Interfaces

2. Checking Station Health

Quick Status

# All services at a glance
systemctl status openwebrx readsb dump978-fa skyaware978 tar1090 status-dashboard vhf-pipeline

# Dashboard (also viewable at :8080)
cat /mnt/nvme/skybridge/status.html

NVMe Health

sudo smartctl -a /dev/nvme0n1         # Full SMART report
df -h /mnt/nvme                        # Disk usage
ls -lh /mnt/nvme/skybridge/            # Data directories

SDR Devices

lsusb                                  # Should show 3x RTL2838
rtl_test -d 0 -t                       # Test BLOGV4
rtl_test -d 1 -t                       # Test UAT978
rtl_test -d 2 -t                       # Test ADSB1090

Network

ip addr show eth0                      # Should be 192.168.1.81
ip addr show wlan0                     # Should be 192.168.1.80
ping -c 3 8.8.8.8                      # Internet connectivity

3. Service Management

Start / Stop / Restart Individual Services

sudo systemctl start <service>
sudo systemctl stop <service>
sudo systemctl restart <service>
sudo systemctl status <service>

Service Names

openwebrx — WebSDR receiver
readsb — ADS-B 1090 MHz decoder
dump978-fa — UAT 978 MHz decoder
skyaware978 — UAT web map
tar1090 — ADS-B web map
status-dashboard — Health dashboard
vhf-pipeline — VHF voice transcription
nvme-backup.timer — Backup scheduler

Restart All Station Services

sudo systemctl restart openwebrx readsb dump978-fa skyaware978 tar1090 status-dashboard

View Service Logs

journalctl -u openwebrx -f            # Follow live
journalctl -u readsb --since "1 hour ago"
journalctl -u vhf-pipeline -n 100     # Last 100 lines

4. VHF Pipeline Operations

Start the Pipeline

sudo systemctl start vhf-pipeline

Requires: OpenWebRX running (provides rtl_tcp on :1235)

Stop the Pipeline

sudo systemctl stop vhf-pipeline

Manual Run (for testing/debugging)

source ~/vhf-pipeline-venv/bin/activate
python ~/scripts/vhf-pipeline.py --freq 121800000 --model tiny.en --vad-threshold 0.005

Run Test Suite

source ~/vhf-pipeline-venv/bin/activate
python ~/scripts/test-pipeline.py

Expected: 17/17 tests pass. Runs without SDR hardware.

Tune VAD Sensitivity

More sensitive (catch quieter transmissions): lower --vad-threshold (e.g., 0.003)
Less sensitive (reduce false positives): raise --vad-threshold (e.g., 0.01)

Check Captured Audio

ls -lh /mnt/nvme/skybridge/vhf-audio/$(date +%Y-%m-%d)/

Check Transcripts

cat /mnt/nvme/skybridge/transcripts/$(date +%Y-%m-%d).txt

5. ADS-B Operations

Check Aircraft Count

# From readsb JSON
python3 -c "import json; d=json.load(open('/run/readsb/aircraft.json')); print(f'Aircraft: {len(d[\"aircraft\"])}')"

Set Station Location

sudo readsb-set-location 61.2181 -149.9003

View ADS-B Data Feed

Web map: http://192.168.1.81:8504
SBS output: nc 127.0.0.1 30003 (BaseStation format)
Beast output: nc 127.0.0.1 30005 (binary)

6. OpenWebRX Administration

Access Admin Panel

Navigate to http://192.168.1.81:8073 → Settings (login required)

Create/Reset Admin User

cd ~/openwebrx
OPENWEBRX_CONFIG_DIR=/var/lib/openwebrx ./venv/bin/openwebrx admin adduser admin

Change SDR Profile

Edit /var/lib/openwebrx/settings.json or use the web admin panel.

7. Backup Operations

Check Backup Status

systemctl status nvme-backup.timer     # Timer schedule
systemctl status nvme-backup.service   # Last run result
ls -lt /mnt/nvme/skybridge/logs/rclone-backup-*.log | head -3

Trigger Manual Backup

sudo systemctl start nvme-backup.service

Configure Backup Remote

The rclone remote skybridge-central needs to be configured:

rclone config
# Choose: New remote → name: skybridge-central
# Choose protocol (SFTP, S3, etc.) based on central server setup

8. Troubleshooting

SDR Device Not Found

# Check USB devices are present
lsusb | grep RTL2838

# Check kernel module isn't grabbing device
lsmod | grep dvb_usb_rtl28xxu
# If loaded: sudo modprobe -r dvb_usb_rtl28xxu
# Blacklist is at /etc/modprobe.d/ (should already be configured)

OpenWebRX Won’t Start

journalctl -u openwebrx -n 50
# Common: SDR device busy (another process using it)
# Fix: stop vhf-pipeline first, then restart openwebrx

VHF Pipeline Can’t Connect

# Check rtl_tcp is available
nc -z 127.0.0.1 1235 && echo "OK" || echo "NOT LISTENING"

# OpenWebRX must be running first (provides rtl_tcp)
sudo systemctl restart openwebrx
sleep 3
sudo systemctl restart vhf-pipeline

No ADS-B Aircraft Showing

# Check readsb is receiving
journalctl -u readsb -n 20
# Check antenna connection
rtl_test -d ADSB1090 -t
# Check JSON output
cat /run/readsb/aircraft.json | python3 -m json.tool | head

NVMe Not Mounted

mount | grep nvme
# If not mounted:
sudo mount /mnt/nvme
# Check fstab entry exists:
grep nvme /etc/fstab

fail2ban Locked You Out

Wait 1 hour (ban duration)
Or access via physical console / different IP
Check bans: sudo fail2ban-client status sshd
Unban specific IP: sudo fail2ban-client set sshd unbanip <IP>

High CPU Usage

top -o %CPU
# Whisper STT can spike CPU during transcription — this is normal
# If persistent: check vhf-pipeline isn't in a crash loop
journalctl -u vhf-pipeline --since "10 min ago"

9. System Maintenance

Update System Packages

sudo apt update && sudo apt upgrade -y

Restart the Pi

sudo reboot

All services are systemd-enabled and will start automatically on boot.

Check Disk Usage

df -h /mnt/nvme /
du -sh /mnt/nvme/skybridge/*/

Rotate Logs Manually

sudo logrotate -f /etc/logrotate.d/skybridge

Check NVMe Wear

sudo smartctl -a /dev/nvme0n1 | grep -E "(Percentage Used|Available Spare|Media Errors)"

10. Known Issues & Open Items

Issue	Status	Notes
dump978 uses device=1 not serial=UAT978	Pending reboot	Update service file after reboot to use serial
Meshtastic node not connected	Awaiting hardware	Pipeline ready; set MESH_HOST or connect USB serial
rclone remote not configured	Awaiting central server	Run `rclone config` when server is ready
Hailo-8 AI HAT+ disabled	By design	NVMe takes M.2 priority; CPU Whisper sufficient for now
readsb location not set	Minor	Run `sudo readsb-set-location 61.2181 -149.9003`

This site is open source. Improve this page.