rf-yvy/tocall-census

TOCALL Census is a monitoring application for the APRS network, a radio-based digital communication system used by amateur radio operators. Every APRS packet contains a destination field called a TOCALL that identifies the software or hardware device that created the packet. By watching which TOCALLs appear in the traffic stream, you can build a real-time picture of which APRS applications and radios are actively deployed across a region or globally. The application connects to APRS-IS, an internet-connected relay that aggregates worldwide APRS radio traffic. You enter a specific TOCALL identifier to track one application or radio firmware, or leave the field blank to count all traffic through a filter. The interface shows live packet counts, a list of recent packets, unique sending stations, and an OpenStreetMap-based map plotting position reports. A scoreboard tracks which US states and countries have produced located packets for the chosen TOCALL. Beyond live monitoring, the app lets you export the current session as a PDF, JSON, or CSV report. It pulls device labels from the APRS Foundation's device identification database so raw TOCALL codes display with human-readable descriptions. You can apply APRS-IS geographic filters to limit incoming traffic to a specific area, reducing load on network servers. No amateur radio callsign or passcode is required for receive-only monitoring. The app is written in Python and runs as a local web server. A portable Windows executable can also be built using PyInstaller. Data is stored locally in a SQLite database file.