Satellite echoing for geolocation and mitigation of GNSS denial

A tangible, non-transitory, computer-readable medium storing program instructions that cause a computer on a processing device to execute a process, the process comprising:

• transmitting, at a transmission time local to the processing device, an initiated message to a communication satellite along a communication path that has a target device with an unknown distance to the communication satellite;
• receiving, at a reception time local to the processing device, a returned message from the communication satellite over the communication path in response to the initiated message;
• determining a time difference between the transmission time and the reception time;
• calculating a distance between the communication satellite and the target device, the distance calculated based on a portion of the determined time difference associated with only a single traversal of a portion of the communication path that is between the communication satellite and the target device;
• and
• performing one or more actions based on the distance between the communication satellite and the target device.

An apparatus, comprising:

• a processor configured to execute one or more processes;
• a communication interface configured to communicate via one or more satellite antennas associated with the apparatus;
• and
• a memory configured to store a process executable by the processor, the process, when executed, configured to perform a process comprising:
• transmitting, at a transmission time local to the apparatus, an initiated message to a communication satellite along a communication path that has a target device with an unknown distance to the communication satellite;
• receiving, at a reception time local to the apparatus, a returned message from the communication satellite over the communication path in response to the initiated message;
• determining a time difference between the transmission time and the reception time;
• calculating a distance between the communication satellite and the target device, the distance calculated based on a portion of the determined time difference associated with only a single traversal of a portion of the communication path that is between the communication satellite and the target device;
• and
• performing one or more actions based on the distance between the communication satellite and the target device.