Train traffic situation display system

A system for determining a separation distance between a first object and a second object, the system comprising:

• a search module associated with the first object, said search module comprising a transponder of the first object having a unique address;
• the search module being configured to transmit a search signal on a first frequency to a second transponder associated with the second object, said second transponder having a different, unique address, said search signal including the address of the transponder of the first object and the address of the transponder of the second object, the search signal being for receipt and processing at the transponder of the second object to locally validate at least the address of the transponder of the second object included in said search signal;
• the search module being configured to receive on said second, different frequency a reply signal transmitted by the transponder of the second object if the validation is positive and to determine a separation distance between the first object and the second object based on a time taken from transmission of the search signal to receipt of the reply signal at said search module;
• and
• wherein the transponder of the first object sends two successive search signals, each of said successive search signals being transmitted in a respective predetermined search repetition period and repeating the process for a next target address.

A method of determining a separation distance between a first object and a second object where each of the first and second objects has a respective transponder with a respective unique address, the method comprising the steps of:

• transmitting a search signal on a first frequency from the transponder of the first object, said search signal including the address of the transponder of the first object and the address of the transponder of the second object;
• receiving the search signal transmitted by the transponder of the first object at the transponder of the second object;
• processing said received search signal at the transponder of the second object to locally validate the address included in said received search signal for the transponder of the second object and, if the validation is positive;
• transmitting a reply signal on a second, different frequency from the transponder of the second object;
• receiving the reply signal transmitted by the transponder of the second object at the transponder of the first object;
• processing said received reply signal at the transponder of the first object to determine the separation distance between the first object and the second object based on a time taken from transmission of the search signal to receipt of the reply signal at said transponder of the first object;
• wherein at least one of the first object and the second object comprises a vehicle movable along a pathway comprising any of:
• a defined pathway;
• a road lane;
• a railway track;
• or a tramway track;
• and
• wherein the reply signal includes pathway data identifying the pathway for the vehicle of the transponder of the second object and the transponder of the first object utilizes the pathway data to determine if the first vehicle is on a same pathway as the object or vehicle of the transponder of the second object.

A system for determining a separation distance between a first object and a second object, the system comprising:

• a search module associated with the first object, said search module comprising a transponder of the first object having a unique address;
• the search module being configured to transmit a search signal on a first frequency to a second transponder associated with the second object, said second transponder having a different, unique address, said search signal including the address of the transponder of the first object and the address of the transponder of the second object, the search signal being for receipt and processing at the transponder of the second object to locally validate at least the address of the transponder of the second object included in said search signal;
• the search module being configured to receive on said second, different frequency a reply signal transmitted by the transponder of the second object if the validation is positive and to determine a separation distance between the first object and the second object based on a time taken from transmission of the search signal to receipt of the reply signal at said search module;
• wherein at least one of the first object and the second object comprises a vehicle movable along a pathway comprising any of:
• a defined pathway;
• a road lane;
• a railway track;
• or a tramway track;
• and
• wherein the reply signal includes pathway data identifying the pathway for the vehicle of the transponder of the second object and the transponder of the first object utilizes the pathway data to determine if the first vehicle is on a same pathway as the object or vehicle of the transponder of the second object.