Glossary

Definitions of RBN and API terminology used throughout the documentation.

RBN (Reverse Beacon Network) Radio
A network of automated receiving stations (skimmers) that detect and report amateur radio transmissions. Think of it as crowdsourced propagation monitoring. Learn more ↗
Spot Radio
A report of a detected radio transmission. Each spot includes the callsign heard, frequency, signal strength (SNR), and which skimmer heard it.
Skimmer Radio
An automated receiver that monitors amateur radio bands and decodes transmissions. Also called "spotter" in the API. Skimmers are distributed globally to provide propagation coverage.
SNR (Signal-to-Noise Ratio) Technical
A measure of signal strength in decibels (dB). Higher numbers mean stronger signals. Negative values mean the signal is weaker than the background noise but still detectable.
Examples:
-20 dB = Very weak
0 dB = Weak
10 dB = Moderate
25 dB = Strong
40+ dB = Very strong
WPM (Words Per Minute) Technical
The speed of Morse code (CW) transmissions. Only present for CW spots. Higher WPM indicates faster code sending. Typical values range from 15-40 WPM.
Cursor-based Pagination API
A pagination method using the after_id parameter. Returns only spots with IDs greater than the specified value. Ideal for real-time monitoring because it never misses new data.
Offset Pagination API
Traditional pagination using offset and limit. Useful for browsing historical data page by page. Can jump to arbitrary pages but may miss/duplicate data if the dataset changes.
Unix Timestamp API
Number of seconds since January 1, 1970 00:00:00 UTC. Used in since and until parameters.
Example: 1704825600 = January 9, 2024 16:00:00 UTC
ISO 8601 API
International standard for date/time representation. Format: YYYY-MM-DDTHH:MM:SSZ. The 'Z' indicates UTC timezone.
Example: 2025-01-09T15:30:00Z
CW (Continuous Wave) Mode
Morse code transmissions. One of the oldest and most efficient modes. CW spots include WPM (speed) information.
FT8 Mode
A digital mode developed by Joe Taylor K1JT. Transmits in 15-second intervals. Highly sensitive, works with weak signals. Very popular for DX contacts.
FT4 Mode
Similar to FT8 but faster (7.5-second intervals). Better for contesting due to higher throughput.
RTTY (Radioteletype) Mode
A digital mode using frequency-shift keying. Common in contests. Predates modern digital modes.
Band Technical
Amateur radio frequency allocations, named by wavelength. Examples: 20m (14 MHz), 40m (7 MHz), 80m (3.5 MHz).
Grid Square (Maidenhead Locator) Technical
A geographic coordinate system used by amateur radio operators. Divides the world into grid squares of decreasing size. 4-character (e.g., FN31) gives ~180km precision; 6-character (e.g., FN31pr) gives ~5km precision.
Examples:
FN31 = Connecticut area
FM19 = Washington DC area
JO62 = Berlin, Germany
Rate Limit API
Maximum number of API requests allowed in a time window. Vail ReRBN allows 100 requests per minute. Check X-RateLimit-Remaining header to see how many requests you have left.
Propagation Technical
How radio signals travel through the atmosphere. Affected by time of day, season, solar activity, and atmospheric conditions. RBN data helps analyze propagation patterns.