§ G · Glossary What does that mean again

Briefly explained,
one line per term.

This site uses a lot of technical jargon. Below is a short translation of what it means and how to read it.

BirdNET: Open-source AI model that recognises bird sounds from three-second audio fragments. Runs on a Raspberry Pi.
Confidence: How sure the AI model is about a species identification, on a scale of 0 to 100 percent. Above 80 percent is usually reliable; below that, treat it with caution.
Vocalisation: The type of sound the bird is making. Distinguishes between song (territory), call (contact), alarm (danger) and other (drumming, begging call).
Spectrogram: A picture of sound. Time runs horizontally, pitch vertically. Brightness shows intensity. Birds and bats each have their own pattern.
Direction category: With a stereo setup (two microphones), a rough estimate of whether the sound came from the north, the south, or straight overhead. Works best for open sky.

kHz: Kilohertz, a thousand vibrations per second. Bat sonar sits between 15 and 100 kHz, just above what a human ear can pick up.
Time-expanded: The bat recording is slowed down 10× so the tones fall within the human hearing range. Sounds like clicking.
BatDetect2: AI model from the University of Tübingen that identifies bat species from ultrasonic recordings.
Bavaria: A second classifier that runs alongside BatDetect2, trained on Bavarian bat data. Useful as a second opinion.
Peak frequency: The pitch at which the sonar call was loudest. Fairly constant per species: common pipistrelle around 49 kHz, noctule around 22 kHz.

MTR: Migration Traffic Rate. The number of birds per kilometre of width per hour passing through a radar window. A measure of how busy migration is.
BirdTAM: Bird Traffic Advisory Map. A European radar map showing bird-migration intensity, produced by cooperating meteorological services.
FlySafe: KNMI system that uses radar imagery to track bird migration, originally built for aviation safety.

Lux: Unit of light level. Full sun is 100,000 lux, an overcast day 10,000, office lighting 500, a full moon 0.2.
Civil dusk: The moment just after sunset when the sun sits 6 degrees below the horizon. It is still just light enough outside to read without artificial light.
Civil dawn: The same thing in the morning, just before sunrise.
Illumination: For the moon: what percentage of the disc is lit. 100 percent is a full moon, 0 percent a new moon.
Altitude: Height above the horizon in degrees. 0 degrees sits exactly on the horizon, 90 degrees is straight overhead.

Davis Vantage Pro 2: Professional weather station that measures temperature, wind, humidity, pressure and rain every 30 seconds. An industry standard for amateurs and researchers.
Barometric trend: Whether air pressure has risen, fallen or stayed stable over the past three hours. Rising often predicts calm weather, falling predicts rain or storms.
Wind rose: A circular diagram showing which direction the wind has been coming from over a recent period, and how often.
m/s: Metres per second. 1 m/s equals 3.6 km/h. A light breeze is 4 m/s; storms begin around 21 m/s.

MobileNetV2: A small AI model that can run fast on weak hardware like a Raspberry Pi. Used here to classify nest-box images by species.
Silero VAD: Voice Activity Detection. Filters human speech out of recordings before they are analysed. Privacy protection.
Whisper: AI speech model from OpenAI. Used here only to detect recordings that contain human voices, so they can be discarded.

ISR: Incremental Static Regeneration. A page refreshes itself automatically when someone visits it, instead of on every push.
SSE: Server-Sent Events. An open connection between browser and server over which events arrive as soon as they happen. Used for the live strip at the bottom of the page.
MQTT: Messaging protocol that lets the Pis publish their detections directly to the NAS. Lightweight and reliable.
Cloudflare Tunnel: Connection from the NAS to the internet without having to open a port on the router. Safer than port forwarding.
BirdNET-Pi: Open-source distribution of BirdNET that listens 24/7 on a Raspberry Pi. Comes with its own web interface and MQTT publishing.