WP5-11 ACO

Navigation system with Anti-jamming and Anti-spoofing features

ID	WP5-11-ACO
Contributor	ACORDE
Levels	Platform, Function
Require	GLAD+ platform WP3-15_2
Provide	Navigation data (position, attitude, velocity)
Input	Specific messages from underlying GNSS receivers.
Output	Jamming and spoofing detection via the user API and Mavlink API
C4D building block	(see WP3-15_2 )
TRL	4
Parent Building block	WP3-15_2
Contact	fernando.herrera@acorde.com

Description and Benefits

One activity of ACORDE in WP5 of COMP4DRONES has been to enable anti-jamming and anti-spoofing capabilities to its low-cost geo-referenced outdoor positioning and attituded estimation solution, i.e. GLAD+ WP3-15_2.

The challenge tackled has been to enable such a feature in a way that:

• hold the low-cost of the solution
• enabled a smooth integration

How

ACORDE has achieved this by tackling the following actions:

• designing and implementing a novel hardware platform that integrates low-cost GNSS receivers with anti-jamming and anti-spoofing capabilities
• at the SW platform level, specific drivers have been developed which enable the positioning application to configure the detection and detect both spoofing and jamming events.
• application-level API has been also enabled. Moreover, a Mavlink semantic extension has been proposed to enable a Mavlink base integration able to transfer spoofing/jamming event information.

Figure below sums up these actions:

Activities on HW/SW platform levels and user API for anti-jamming and anti-spoofing support in GLAD+

The figure below shows the definition of the ESTIMATOR_STATUS Mavlink message.

The semantics of this message has been smoothly widen to provide the quality information on the positioning parameters. The expressive power of the ESTIMATOR_STATUS message has been improved, by defining extra ranges within the default invalid range (1.0<V) of theinnovation test ratio field. These ranges provide additional information on the root causes of the abnormal measurement. An additional benefit of the proposed extension is that it maintains backward compatibility with existing MAVLink integrations.

Default ESTIMATOR_STATUS message definition

Evaluation

The evaluation performed consisted in verifying that the enablinh/diabling and configuration of the spooging and jamming capabiltiies could be done, and that their correspondign detection events were correctly send to the navigation application and to the user level interfaces.

The configuration through a simple .ini file was tested, as illustrated in the following figure:

User settings file with new parameters for spoofing&jamming configuration (in blue and red respectively)

Via this type of file, different configurations were performed, with their later corresponding runs of GLAD+ application on the HW platform upgraded during the COMP4DRONEs project. For these experiments, GLAD+ application debug traces were enabled. These traces enabled the application to dump the spoofing and jamming status obtained from the driver-level API into a log, as the one shown in the following figure.

Debug trace showing the status of the detection of spoofing (in blue) and jamming (in red) when both features are enabled

As can be noticed, the configuration shown in the former figure enabled both spoofing and jamming detection. In addition, specfic parameters for jamming detection, i.e. threshold for pure carrier jamming (15dB) and for broadband jamming (3dB) were provided. According to this configuration, the log excerpt shows corresponding spoofing and jamming status messages. In this case, spoofing free and low-level jamming scenario is detected.