From: Andrew Johnson
Date: 2010-06-04 19:08:20
I was asked a couple of follow up questions and I have posted answers to these here, along with the original information: www.checktheevidence… AirNav Radarbox can be purchased in various places, including e-bay: The cost includes a 12-month subscription to the database service which allows a number of the various flight details to be downloaded. Using the Radarbox over time allows data to be captured and I am hoping to make some comparative measurements between days with no trails and days with high numbers of trails to see what emerges. Some of the log files I have collected have 800,000 lines of data Like quite a few people I was surprised to detect this result – as I had kind of assumed that only unmarked planes would be “caught” making trails. I was asked by someone about the AirNav RadarBox picking up military flights. Here are the notes from the manual for the unit: Why can I see aircraft in the list but they do not appear on the map? Some aircraft, although they are fitted with ADS-B equipment, do not transmit their position. Without position information, it is impossible to display the aircraft on the map. In the example below, the first 2 aircraft in the list have ADS-B equipment, but they are not transmitting position information. However, it is still possible to see the identity and type of the aircraft and their altitude. The last 2 aircraft are transmitting full position information (shown by the Globe in the first column) and will appear on the map. Note that military aircraft will often show in the aircraft list, but for security reasons, do not transmit their position. Some civilian flights do not broadcast their position either – only their height – and some don’t broadcast anything.
