Definition:  Coherent transmission and reception of signals by combining antennas mounted on moving platforms such as UAVs or satellites.  Another description of this type system is an array constellation.

Challenges: 

  1. Time/phase synchronization of antennas

  2. Spatial synchronization of antennas

  3. Near-field antenna array pattern control including reduction of radiation in unwanted directions

  4. Self-organization of array nodes

Advantages: 

Built-in redundancy for anomaly mitigation

Precision and/or spot jamming with friendly-COMM avoidance

Precision near-field beamforming

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Specialized Arrays Inc.  700 Wavecrest Ave. Unit 103, Indialantic, Fl 32903

State-of-the art in moving platform transmit arraying

  1. Look-ahead beam pointing

  2. Look ahead near-field pattern control for reducing radiation in unwanted regions

  3.  Multi-beam, partitionable operation for dynamic reallocation of node function

  4.  Nodes are self-aware and can reorganize in the event of a node failure or availability of additional nodes

Spatial synchronization: a dynamic constellation array geometry is established

  1. Node position:  Relative node positions are autonomously determined and continually tracked, defining a lattice
  2. Platform orientation:  Each platform orientation is continually determined with respect to the lattice 
  3. Array orientation with respect to ENU:   Heading and attitude for each node in the  constellation is continually calculated for target pointing.

Precision time synchronization: pico-second accuracy for wireless, static, or moving platforms  

  1. Required for open-loop coherent transmission from relatively moving antennas to a target of interest
  2. Doppler effects due to relative node-to-node and node-to-target motion are accommodated
  3. New technology is a major advance over time transfer methods developed and demonstrated on the NASA-funded TxACE program, 2010
  4. Our method does NOT requires amplitude and phase balance of the reference wave and its reflection as in US Patent 8,170,088  "Methods for Determining a Reference Signal at any Location Along a Transmission Media"
Wireless Moving Platform Coherent Transmit