You BUMPED a post. Dear "insert whatever divine being you call upon here" :shock:
Lastbesthope will be hunting you down now :lol:
Anyway if you survive long enough have a look at page 108 of the MongT rules. This lists the types of Electronics packages, what sensors they contain (all have visual as a default) and any dice modifiers for jamming etc.
Standard civilian and basic civilian are exactly the same units, the standard electronics package has a larger sensor array and processor making it a bit harder to jam, otherwise that is it. Once you hit the military stuff you are adding more sensor types and a jammer.
The military stuff in MongT is far more resistant to jamming but everything uses the same range chart so basic civilian Radar and Very Advanced military radar both have the same performance. However it is much easier (-4) to jam the radar on a basic civilian rig than on a very advanced military setup (+2) meaning that your dirt cheap civilian ship will know something is out there since its radar is a hash of rubbish and jamming but not have a clue who, where or how many.
The rules don’t actually say anything about detecting planets, I think it is simply assumed that your charts and sensors will show where everything major is in the system as soon as you jump in. For unexpected items there are no exact rules given, it is very much a case Ref make it up.
In 2300 you have significantly longer ranges on the military units (up to 7 LS). It does mention that you can detect an active radar unit at twice the range. In addition a ship with a transponder is going to be detectable at whatever range the signal reaches which is going to be light minutes at least though you are detecting where the signal was at the time it was broadcast.
Re your questions. Yes, Yes and Yes.
Grav sensors are not the replacement for densitometers. The grav sensor has a system wide range for detecting gravity fields the size of worlds and out to several light minutes for much smaller gravity fields such as stutter warps. You can vary this based on the drive size and strength.
The Densitometer is replaced by the deep scan, think deep penetrating ultra high frequency radar. This has a very short range but is capable of scanning through the hull and providing deck plans and ship layouts.
An example in 2300 would be:
Your convoy crosses the shelf and drops to sub light speeds. The military escort has a Grav scanner which sweeps nearby space and the entire system. This locates the sun, worlds and moons across the system and the stutter warp drive fields of the nearby ships in the convoy.
Visual scanners on the escort and civilian ships also detect the light from the systems sun and planets.
All ships are broadcasting radar, the escort can pick up returns from 5 light seconds away because of much better software and hardware, and the cheap civilian units need a much stronger return from a target within 1 LS to be able to process the signal return.
All of them will also be picking up radio signals from the system which would include the main world, any stations or platforms and any nearby ship transponders. A ship that jumped in an hour before them would be detected since its transponder is broadcasting its location. A ship that jumped in an hour ago two light hours away along the edge of the shelf with its transponder on would also be automatically detected but not for another hour since it takes two hours for its signal to cross two light hours.
So the convoy forms up and heads in toward the planet. Ten hours later the ship that is two light hours to the side of them changes its transponder to “Under Attack” and begins to radio a mayday. It takes two more hours for this message to reach the convoy by which point the ship is already dead.
The convoy picks up this signal reporting the cargo ship under energy weapon attack from an enemy outside of detection range, this signal then cuts off.
The escort commander orders the convoy to turn and move away from the last known position of the dead ship and towards the shelf edge as that is much closer than the world. Before the convoy turns he orders all transponders turned off since they are giving away the convoys location. Since the grav sensor can detect a drive field at several light minutes which is well beyond the range where even advanced passive sensors could detect the ships radar emissions he leaves them on.
The raiders have been watching the convoy via the transponders, having killed the lone target they now turn towards the convoy and begin to chase it. Once the convoy turns off its transponders the raiders being two light hours away will know where the convoy was at the point they turned off the transponders which will reach them two hours later.
The raiders split up and sweep the area with Grav sensors and watch for radio or visual signals.
The convoy follows the escorts orders but then splits up, several ships want to run for the world, one drops its cargo pod and runs off at full speed, another tries to follow it, a third runs directly for the shelf. The escort orders them to rejoin the convoy but they all refuse. The escort is using directional radio broadcasts but the civilians are using general broadcasts which reveal their positions and will give the raiders a new course once the signals reach them.
The raiders are at full speed and closing. The escort takes position half a light minute behind the remaining convoy.
The raiders catch up. The escort detects three drives on its grav sensors, the raiders can detect the escort, the slowest of the two ships running to the world and the ship running directly to the shelf. The raiders split up, the destroyer heads for the escort and one fighter goes after each civilian ship.
At this point the escort can only watch helpless as the two fighters close in, guided by the grav sensors on the destroyer. At 5 Light seconds the fighters own radar gets a lock and they are able to close in and open fire at two light seconds of range. The two civilian ships take hits from an enemy outside of their own 1LS radar range and die slowly. The pod carrier is outside of range of the grav sensor and well outside of range of the fighter’s radar and so runs to safety. The fighter can pursue the pod carrier, they detected is radio messages so they know it is here somewhere but since the pod carrier is outside of the grav sensors range the fighter it is limited to its own radar range of 5 light seconds. The pod carrier runs away and is very likely to escape.
The escort turns to engage the destroyer to buy time for the convoy to run. The remaining convoy ships are ordered to shut down radar, change course and keep running. Then the crew of the escort try to sell their lives well.
The remaining ships of the convoy have shut down radar and are on passive radio and visual. As they run they will detect the visual explosions and radio calls for help that mark the deaths of the two civilian ships that fled. They will know where the raider destroyer is as long as the escort keeps using directional radio signals to update them.
If the raider kills the escort and is still intact the convoy are now alone in the dark, with an enemy ship hunting them and completely blind. They can talk to each other using directional radio or send calls for help to the world in the same way but if the destroyer is able to get close enough to detect them on its grav sensors they are likely to die.
One option they do have is to shut down their stutter warp drives and drift, if the escort is destroyed and the raider is still after them this may be all that can save them but they will need to be on a different course to the escort or the raider will follow the original course and will find them with radar anyway.
