I have added transponders to ships. This is a way for a ship to identify itself to other Empires if it wishes to do so. When a ship is built or refitted, the transponder will automatically be set to the class of the ship and the status will be inactive. Each ship can change it's transponder to any class of that race or to any alien class for which you have learned the transponder codes. You can activate/deactivate the transponder and set its class on the Ship window and there are also new Activate and Deactivate Transponder fleet orders.
Transponders will also be used for any civilian traffic when I get around to adding it (unless the civilian decides to falsify or deactivate the transponder at some point and turn pirate
). They could also be used for IFF in the case of future minefields or fire and forget missiles.
Another possible use would be two or more Empires creating a treaty which made transponders mandatory in certain systems, Obviously there are a lot of deception possibilities around transponders.
I gave a lot of thought to the actual mechanics of the transponder. There were two main possibilities; broadcast or query. Broadcast simply means that turning on the transponder would show your position and transponder code to any other ships or pops in the same system. That would be the extent of the information though. An alien race would still have to bring you within sensor range to get any confirmation of what you are telling them.
A query system, which is how this works in real life, would require an alien race to detect you first and then interrogate the transponder. This could be done automatically or manually. An automatic system would initiate the query as soon as any type of sensor (Active, thermal or EM) detected the ship. A manual system would require the player to select a contact from a list to initiate the query. There are a couple of additional complications with queries though. Firstly, without some common frame of reference there is no way for alien races that have not previously met to develop an interstellar standard for interrogation protocols and transponder codes. Secondly, if a transponder is queried, the ship carrying that transponder would certainly know about it, which means the more labourious manual process would certaily be preferable to most players.
Therefore, I think by far the simplest solution is to go with the broadcast option. A standalone transponder signal will be represented on the map as an icon with an associated transponder ID. If you also have a sensor contact for the same ship, the Transponder information would be included in the contact data instead. I'll automatically add any alien transponder codes to the Tac Intelligence window if your sensors match up a active sensor contact with a transponder. I'll also allow you to associate an ID with a known alien class on the Tac Intelligence window so that in future transponder IDs for that class will be shown by the alien class name instead.
Steve
