Advanced networking, detection, and data visualization techniques in multiple networked devices
View Patent ↗A soldier-portable mixed-reality system provides centimeter-accurate positioning, electronic-warfare-hardened communications, and multi-spectral visualization without reliance on GPS or fixed infrastructure. Each head-mounted device contains a chip-scale atomic clock, isotropic time-of-flight ranging radios, a beam-steered software-defined radio, a modular sensor rail, and a see-through display. Wireless precision-time-protocol exchanges hold inter-device clock error below 0.5 ns, enabling cooperative multilateration for self-generated three-dimensional pose. An adaptive “Whisper-Mesh” waveform senses jamming, hops frequency, tight-beams at ≤5° width, and transmits in <5% duty-cycle bursts for low probability of detection. Sensor fusion combines visible, infrared, and targeting data with <10 ms latency, projecting reticles and tactical icons on the visor. A vehicle gateway preserves nanosecond timing over back-haul links, and unmanned drones extend coverage through reconfigurable formations. Energy-aware scheduling balances compute across nodes, extending mission endurance. The system maintains navigation, secure communication, and weapon-aiming accuracy in GPS-denied, contested environments.
1 . A tactical augmented-reality system, comprising:
a plurality of head-mounted computing devices, each device including a see-through display, an inertial measurement unit, a precision timing clock, a time-of-flight ranging module, and a software-defined radio transceiver;
one or more unmanned aerial vehicles communicatively linked to the head-mounted computing devices as relay nodes;
a vehicle-mounted gateway node configured to join a wireless mesh network formed by the head-mounted devices and to interface that mesh network with an external communication network; and
a control system configured to synchronize clocks among the head-mounted devices to within sub-nanosecond accuracy, to determine relative positions of all head-mounted devices by multilateration of time-of-flight range measurements, and to present augmented-reality information to users via the see-through displays in real time, wherein the software-defined radios of the head-mounted devices automatically adapt transmission parameters to mitigate detected interference and maintain low probability of intercept, and wherein the unmanned aerial vehicles are operable in a coordinated swarm to extend communication coverage and sensor range for the head-mounted devices.
2 . The system of claim 1 , wherein the plurality of unmanned aerial vehicles (UAVs) maintain an octahedral formation during normal operation and dynamically reconfigure into a linear relay chain formation in response to detection of an obstacle blocking line-of-sight communication between the UAVs and the head-mounted devices.
3 . The system of claim 1 , wherein the vehicle-mounted gateway node is configured to bridge data communications from the wireless mesh network to the external communication network while maintaining a transfer-of-time error not exceeding five nanoseconds between a time reference of the wireless mesh network and a time reference of the external communication network.
4 . The system of claim 1 , wherein each software-defined radio is configured to transmit voice and data in short bursts such that an average transmit duty cycle does not exceed five percent.
5 . The system of claim 1 , wherein each software-defined radio is configured to change its operating frequency according to a pseudorandom hopping sequence upon detecting that a signal-to-interference-plus-noise ratio of a current channel has fallen below a threshold.
6 . The system of claim 1 , wherein each software-defined radio includes a beam-steerable phased-array antenna that produces a principal radiation lobe with a half-power beamwidth of no more than five degrees and with sidelobe levels at least 25 dB down from the principal lobe.
7 . The system of claim 1 , wherein each head-mounted computing device is further configured to enter a radio-silent mode in which the software-defined radio ceases transmission and the device continues to track its position by performing visual-inertial odometry with keyframe anchoring to a last known reference frame until communications are re-enabled.
8 . The system of claim 1 , wherein the system further comprises a distributed task scheduler that allocates computational workloads among the head-mounted devices, the one or more unmanned aerial vehicles, and the vehicle-mounted gateway node in accordance with remaining battery energy of each node so as to extend overall mission runtime without degrading augmented-reality performance.
9 . The system of claim 1 , wherein the wireless mesh network is switchable to a time-of-flight-only ranging mode in which high-bandwidth data transmissions are disabled and each device exchanges only ranging pulses using omnidirectional antennas to measure inter-device distances.
10 . The system of claim 1 , wherein the vehicle-mounted gateway node prioritizes time-critical pose update packets over lower-priority data packets when available communication bandwidth to the external network is limited.
11 . A method of providing coordinated localization, communication, and sensing for a team of users in a GPS-denied environment, the method comprising:
transmitting, from each of a plurality of head-mounted augmented-reality devices carried by the users, a short ultra-wideband ranging pulse or packet that includes a transmit timestamp generated by a local high-stability clock on the device;
wirelessly synchronizing the clocks of the plurality of head-mounted devices to within 0.5 nanoseconds root-mean-square of each other by exchanging timestamped signals among the devices;
computing a set of inter-device distances by comparing transmit timestamps to corresponding receive timestamps for signals exchanged between each pair of devices;
determining a three-dimensional relative position for each of the head-mounted devices by multilateration based on the set of inter-device distances and on inertial measurements from the head-mounted devices;
deploying a plurality of unmanned aerial vehicles in a predetermined formation to form an airborne communication relay and sensing network linked with the head-mounted devices;
collecting sensor data from the unmanned aerial vehicles in coordination with the head-mounted devices using the synchronized clocks as a common time base; and
reconfiguring the formation of the unmanned aerial vehicles into a relay chain configuration in response to detecting an obstacle that prevents direct radio communication between at least two of the head-mounted devices.
12 . The method of claim 11 , further comprising relaying time-stamped data from the wireless mesh network of head-mounted devices through a vehicle-mounted gateway node to an external communication network, while preserving a time synchronization offset between the wireless mesh network and the external communication network to within five nanoseconds.
13 . The method of claim 11 , further comprising monitoring communication channel conditions on the wireless mesh network and automatically hopping the software-defined radios to new frequencies according to a pseudorandom sequence upon detecting that a signal-to-interference-plus-noise ratio on a current frequency has dropped below a defined threshold.
14 . The method of claim 11 , further comprising limiting transmissions on the wireless mesh network to intermittent bursts such that an effective transmission duty cycle does not exceed approximately five percent during normal operation.
15 . The method of claim 11 , further comprising steering a narrow communication beam from each head-mounted device toward a target receiver and reducing transmit power to a minimum level sufficient to maintain a reliable link, so as to reduce the probability of intercept of communications among the head-mounted devices.
16 . The method of claim 11 , further comprising, in response to a command to maintain radio silence, ceasing active radio-frequency emissions from each head-mounted device and each unmanned aerial vehicle and tracking the position of each head-mounted device by visual-inertial odometry that anchors newly detected visual keyframes to a last-known reference frame of the device until radio communications are restored.
17 . The method of claim 11 , further comprising distributing portions of an application workload among different ones of the head-mounted devices, the unmanned aerial vehicles, and the vehicle-mounted gateway node based on respective remaining battery levels of those devices, such that devices with greater available energy budget execute a larger share of the workload.
18 . The method of claim 11 , further comprising transitioning the wireless mesh network into a time-of-flight ranging only mode by disabling high-bandwidth data communications and exchanging only time-of-flight ranging signals among the head-mounted devices and the unmanned aerial vehicles to maintain relative positioning updates while minimizing radio-frequency emissions.
19 . The method of claim 11 , further comprising deriving a new encryption session key for communications on the wireless mesh network within 200 milliseconds of detecting a jamming attack, and seamlessly switching all mesh network nodes to the new session key to thwart the jammer.
20 . The method of claim 11 , further comprising reducing a frequency of active ranging signal exchanges between the head-mounted devices when a measured acceleration of the users falls below a predetermined threshold, in order to conserve battery power during periods of user inactivity.