Drone ID Plus

Introduction

In the United States, every drone flying in regulated airspace must include a transponder (either built-in or external) that broadcasts ID/flight data in real time. The data is broadcasted under the Remote ID protocol and is mainly used by regulatory authorities like airports or law enforcement to track drones. Overall, think of it as a “license plate” for drones.

Open Drone ID is an open implementation of the Remote ID standard. It adheres to the official protocols defined by ASTM F3411 and related standards, making it possible for the public, not just regulatory authorities, to decode and display drone identification information.

We believe anyone should be able to identify the drones above them, and that you should care what is flying over your home.

The project itself is currently tested with these commercial transponders and works!

1. Ruko R111

Project Outline

This is meant as an exploratory project to understand the RemoteID protocol and its implications. The project is divided into three main components:

1. Parse Remote ID Packets:
   Decode Open Drone ID messages emitted by drones and transponders.
2. Integrity Checks:
   Validate these packets to help ensure they are authentic and not spoofed.
3. Range Analysis:
   Determine the maximum distance at which Remote ID packets can be detected.

Open Drone ID Protocol

Open Drone ID packets are transmitted by drones (or their transponders) over Bluetooth Low Energy (BLE) and follow a fixed-format structure. Each individual message is 25 bytes in length. In some cases, multiple messages are bundled together in a Message Pack to overcome the BLE advertisement size limitations.

The parser extracts a header (1 byte) from the raw payload, which determines the message type and protocol version, and then parses the remaining 24 bytes according to the message type.

Packet Structure

General Message Format (25 bytes)

• Header (1 byte):
  • High nibble (4 bits): Message Type
  • Low nibble (4 bits): Protocol Version
• Payload (24 bytes):
  The remaining bytes contain the data fields defined by the message type.

Message Types

The following table summarizes the message types and their key fields:

Message Type	Enum Value	Key Fields	Description
BASIC_ID	0	idType, uaType, UAS ID	Basic identification information (drone identifier)
LOCATION	1	status, heightType, EWDirection, speedMult, Direction, speedHori, speedVert, droneLat, droneLon, height	Location and flight parameters (position, altitude, speed)
AUTH	2	authType, authDataPage, authLastPageIndex, authLength, authTimestamp, authData	Authentication data
SELFID	3	descriptionType, operationDescription	Self-identification message (e.g., emergency, status)
SYSTEM	4	operatorLocationType, classificationType, operatorLatitude, operatorLongitude, areaCount, areaRadius, areaCeiling, areaFloor, operatorAltitudeGeo, systemTimestamp	System data, including operator location and classification
OPERATOR_ID	5	operatorIdType, operatorId	Operator identification (a fixed-length string)
MESSAGE_PACK	0xF	Contains multiple messages; first 1 byte header, 2 bytes pack details, then concatenated messages (each 25 bytes)	A container for multiple Open Drone ID messages

UA Type Information

The uaType field in the BASIC_ID message indicates the type of unmanned aircraft. The following table describes the supported UA types:

Value	Name	Description
0	MAV_ODID_UA_TYPE_NONE	No UA (Unmanned Aircraft) type defined.
1	MAV_ODID_UA_TYPE_AEROPLANE	Aeroplane/Airplane. Fixed wing.
2	MAV_ODID_UA_TYPE_HELICOPTER_OR_MULTIROTOR	Helicopter or multirotor.
3	MAV_ODID_UA_TYPE_GYROPLANE	Gyroplane.
4	MAV_ODID_UA_TYPE_HYBRID_LIFT	VTOL (Vertical Take-Off and Landing). Fixed wing aircraft with vertical takeoff.
5	MAV_ODID_UA_TYPE_ORNITHOPTER	Ornithopter.
6	MAV_ODID_UA_TYPE_GLIDER	Glider.
7	MAV_ODID_UA_TYPE_KITE	Kite.
8	MAV_ODID_UA_TYPE_FREE_BALLOON	Free Balloon.
9	MAV_ODID_UA_TYPE_CAPTIVE_BALLOON	Captive Balloon.
10	MAV_ODID_UA_TYPE_AIRSHIP	Airship (e.g., a blimp).
11	MAV_ODID_UA_TYPE_FREE_FALL_PARACHUTE	Free Fall/Parachute (unpowered).
12	MAV_ODID_UA_TYPE_ROCKET	Rocket.
13	MAV_ODID_UA_TYPE_TETHERED_POWERED_AIRCRAFT	Tethered powered aircraft.
14	MAV_ODID_UA_TYPE_GROUND_OBSTACLE	Ground Obstacle.
15	MAV_ODID_UA_TYPE_OTHER	Other type of aircraft not listed earlier.

Validation and Integrity Checks

To ensure the authenticity and reliability of the received data, Drone ID Plus implements several validation rules. These checks help flag potentially spoofed or erroneous messages before they are further processed or displayed. The primary validations include:

1. Location Data Validation:

   • Distance Check:
     The drone’s reported location is compared to a known reference point (such as a base station). Using the Haversine formula, if the drone is more than a set threshold (e.g., 1000 meters) away from this reference, a warning is raised.
   • Speed Check:
     Horizontal and vertical speed values are validated against expected ranges. For instance, horizontal speeds exceeding 100 m/s or vertical speeds above 50 m/s are flagged as suspicious.

2. Basic Identification Validation:

   • UA Type Check:
     The uaType value is validated to ensure it falls within the acceptable range (0 to 15). If the value is outside this range, the message is flagged as invalid.
   • UAS ID Verification:
     The UAS ID, which identifies the drone, is checked to ensure it is not empty and conforms to expected formatting. An empty or malformed UAS ID triggers a warning.

3. Operator Identification Validation:

   • White-list Based
     We utilize a (for now hardcoded) white-list of known operator IDs to validate incoming messages. If the operator ID is not found in the white-list, a warning is generated. In the future, an ABAC system is proposed. This is due to the fact that the resource (drones) may have various roles, and the users of the app (civilians, law enforcement, etc.) may have different permissions to access the data.

Expected Payload Length

• Single Message: 25 bytes
• Message Pack: Up to 228 bytes (1 byte header + 2 bytes for pack details + 9 messages × 25 bytes = 228 bytes)