Apparatus, system, and method for mitigating systematic distance errors in radar-based triangulation calculations

An artificial reality system comprising:

• a wearable device dimensioned to be worn by a user;
• at least one processing device;
• a set of radar devices secured to the wearable device, wherein the set of radar devices:
• transmit radar signals to at least one transponder that modifies the radar signals by shifting the radar signals by a certain amount of frequency to enable the processing device to accurately measure distances between the set of radar devices and the transponder even when the transponder is located within a minimum distance threshold of the set of radar devices, wherein the minimum distance threshold is outside a detection range of the set of radar devices;
• and
• receive the radar signals returned from the transponder;
• an error-mitigation device secured to the wearable device, wherein the error-mitigation device provides, to the processing device, data for mitigating position errors in triangulation calculations involving the radar signals;
• and
• wherein the processing device:
• calculates, based at least in part on roundtrip flight times of the radar signals and the data, distance measurements that represent distances between the set of radar devices and the transponder;
• and
• triangulates, based at least in part on the distance measurements, a three-dimensional location of the transponder relative to the wearable device.

A method comprising:

• transmitting, by a set of radar devices secured to a wearable device worn by a user of an artificial reality system, radar signals to at least one transponder that modifies the radar signals by shifting the radar signals by a certain amount of frequency to enable at least one processing device to accurately measure distances between the set of radar devices and the transponder even when the transponder is located within a minimum distance threshold of the set of radar devices, wherein the minimum distance threshold is outside a detection range of the set of radar devices;
• receiving, by the set of radar devices, the radar signals returned from the transponder;
• obtaining, by the processing device from an error-mitigation device secured to the wearable device, data for mitigating position errors in triangulation calculations involving the radar signals;
• calculating, by the processing device based at least in part on roundtrip flight times of the radar signals and the data, distance measurements that represent distances between the set of radar devices and the transponder;
• and
• triangulating, by the processing device based at least in part on the distance measurements, a three-dimensional location of the transponder relative to the wearable device.