The Captain Musick den hosts an ADS-B Receiver for the FlightRadar24 network. This is a small, RaspberryPi-based device that collects identification data broadcast by aircraft in the area, and then sends it back over the Internet to the central servers. People are then able to view real-time information about aircraft in the area, via either the FlightRadar website, or the Mobile Application.
Due to our contribution, we receive a full Business Subscription to the service. This allows up to 4 devices simultaneously, with no advertising or time restriction, and the ability to view all available data, even historical data back up to 2 years. Leaders have access to the credentials for the CMAS account, but anyone can sign up for a free account if they wish.
The mobile application allows you to view what is in the air nearby at the moment; it also has an AR mode where you can point the camera at the sky and view information on whatever aircraft are visible. You can view flight paths from training flights at Ardmore, millitary planes flying out of Whenuapai, and the Westpac Rescue helicopter on emergency rescue runs.
If you would be interested in building a Receiver, then it is very simple to do and instructions are available on the website. You can obtain a Raspberry Pi from Jaycar, ($99 for a model 3 but a model 2 will work as well) and a USB ADS-B from Aliexpress for US$10. Aliexpress also sell (cheaper) Raspberry Pi 3 modules. Memory cards and USB charger units are easy to obtain, as are network cables to connect your device to your Internet router.