Node Source Tracking and Direction of Arrival Estimation

This section describes operational behavior for source tracking and DoA estimation. Implementation details are deferred to algorithm design documents.

1. Phased-Array Direction Estimation Using IQ Samples

The phased-array estimates source direction from phase and amplitude differences across synchronized antenna channels.

Outputs:

• Candidate directions (azimuth, elevation)
• Confidence values per candidate
• Signal quality (power/SNR)

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2. MUSIC Algorithm (Multiple Signal Classification)

When to use: Dense RF scenes, multiple emitters, prioritizing angular resolution

Characteristics:

• Higher resolution, higher CPU cost
• Requires source-count estimate
• Sensitive to array calibration quality
• Moderate update rates for CPU budget

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3. ESPRIT Algorithm (Estimation of Signal Parameters via Rotational Invariance Technique)

When to use: Continuous tracking loops, moderate emitter separation, faster updates needed

Characteristics:

• Lower latency than MUSIC
• Reasonable separation performance
• Depends on array calibration and source-count assumptions

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4. Beam Power Maximization Algorithm

When to use: Coarse acquisition, strong-signal scenarios

Characteristics:

• Simplest approach
• Evaluate power across steering directions, use strongest response
• Suitable for initial lock acquisition

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5-7. Multi-Target Tracking, Tracking Loops, GNU Radio Integration

See Section 12 of the archived monolithic node architecture document for detailed descriptions.

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Related: See System-AntennaCapabilities for operational tracking modes.