I currently wring some Python code to parse the data found in the aircraft.json file from my Raspberry Pi. I’m also working on documenting the information found in the file. Using Copilot, reading articles online, and looking at net_io.c file from the dump1090 github I’ve been able to cobble this together. For the most part I believe this info is correct, but I’d like some feedback on the accuracy.
now - The time at which the data was collected, represented as Unix epoch time (seconds since January 1, 1970, 00:00:00 UTC).
aircraft - An array of objects, with each object representing data for a single aircraft.
hex - A unique identifier for the aircraft, typically its Mode S transponder code in hexadecimal format.
flight - The flight number or identifier assigned to the aircraft.
alt_baro - The aircraft’s altitude measured by its barometric altimeter, typically in feet.
alt_geom - The aircraft’s geometric altitude, calculated based on its position relative to the Earth’s surface, typically in feet.
gs - The speed of an aircraft relative to the ground, typically in knots.
track - The aircraft’s track, the direction it is moving in degrees, measured clockwise from true north.
geom_rate - Measures the rate of change in geometric altitude, which is the actual altitude above mean sea level
baro_rate - The rate of change of the aircraft’s barometric altitude, typically in feet per minute, indicating ascent or descent.
geom_rate - The rate of change of the aircraft’s geometric altitude, typically in feet per minute, indicating ascent or descent.
squawk - The transponder code set by the pilot, typically a four-digit octal code used for identification and communication with air traffic control.
emergency - Indicates any emergency situation the aircraft may be experiencing. Depending on the issue the squawk code reported could be 7500 (hijack),7600 (radio failure) or 7700 (technical, mechanical or medical), If there is no emergency this is set to none. Depending on the squawk reported, Possible values are: “general”,“minfuel”, “nordo”, “unlawful” and “downed”
category - This is the aircraft’s type catagory. Examples include “A1”, “A2”, “A3”, “A5”, “A6”.
nav_qnh - The altimeter setting, or barometric pressure, used by the aircraft’s navigation system, typically in hectopascals (hPa).
nav_altitude_mcp - The altitude set on the aircraft’s Mode Control Panel (MCP), the interface used by pilots to control the autopilot, typically in feet.
nav_heading - The heading set on the aircraft’s MCP for the autopilot to follow, typically in degrees.
lat - The aircraft’s latitude, its position north or south of the equator, measured in decimal degrees.
lon - The aircraft’s longitude, its position east or west of the prime meridian, measured in decimal degrees.
nic - Navigation Integrity Category (NIC), a measure of the accuracy and reliability of the aircraft’s navigation system.
rc - The aircraft’s reception quality, likely indicating the strength of the signal received by the ADS-B receiver.
seen_pos - The time in seconds since the aircraft’s position was last updated.
version - The version of the ADS-B message format being used by the aircraft.
nic_baro - Navigation Integrity Category for barometric altitude data, a measure of the accuracy of the barometric altitude information.
nac_p - Navigation Accuracy Category for position data, a measure of the accuracy of the aircraft’s position.
nac_v - Navigation Accuracy Category for velocity data, a measure of the accuracy of the aircraft’s speed and direction.
sil - Source Integrity Level (SIL), a measure of the overall reliability and trustworthiness of the ADS-B data from the aircraft.
sil_type - The type of SIL being used, which could be “perhour”, “persample”, or “unknown”.
gva - Geometric Vertical Accuracy, a measure of the accuracy of the geometric altitude data.
sda - System Design Assurance, a measure of the level of confidence in the design and performance of the ADS-B system on the aircraft.
mlat - Multilateration (MLAT) data, used to determine the aircraft’s position when it is not broadcasting its own position.
tisb - Traffic Information Service – Broadcast (TIS-B) data, providing information about other aircraft in the vicinity, broadcast by ground stations.
messages - The number of ADS-B messages received from the aircraft.
seen - The time in seconds since the last ADS-B message was received from the aircraft.
rssi - Received Signal Strength Indicator (RSSI), a measure of the strength of the ADS-B signal received from the aircraft.
nav_modes - Defines the navigation modes currently active on the aircraft, such as “althold”,“autopilot”, “vnav”, “lnav”, “tcas”, and “approach”.
I’m not quite sure of the data for category. I had some information that suggests that ‘A1’, ‘A2’ and etc., are subcategories that describe a description of what I’ve seen as Category A which describes small civil aircraft. I haven’t been able to locate the documentation I found previously that contained the info.
I am plaining to make the code available on GitHub soon. I’m able to successfully use retrieve and print out the data. If you’re familiar with Python I’m using the requests library to retrieve the data and I’m using pandas to access the data.
Thanks for any feedback in advance.
