Range of Densitometers

[sideranautae]

According to the CRB the max range to detect a craft (assume smallest small craft) is ~10,000km. Assuming that is about 10mt mass, what would be the detection range for something like Earth's Moon?

I get ~7,345,900,000,000,000km. (That's 776 light years!) when I do a straight mass comparison and distance multiplier based on the Moon's mass vs. 10mt.

Thoughts based on stated ranges in the CRB?

 

[sideranautae]

So much for rogue planets & Brown dwarf stars going undetected in the :lol: Trav universe.

 

[Infojunky]

According to the CRB the max range to detect a craft (assume smallest small craft) is ~10,000km. Assuming that is about 10mt mass, what would be the detection range for something like Earth's Moon?

I get ~7,345,900,000,000,000km. (That's 776 light years!) when I do a straight mass comparison and distance multiplier based on the Moon's mass vs. 10mt.

Thoughts based on stated ranges in the CRB?

That makes the assumption that a Densitometer range has anything to do with the mass of the target. I for one have considered them to be part of the active array, thus range is limited to the range where returning signals can be readily identified, with the proviso that Active gravity systems give a bit of a boost to results (i.e. Jump entry into a system making a Noise that a Densitometer hears in very none directional sense).

 

[sideranautae]

That makes the assumption that a Densitometer range has anything to do with the mass of the target.

Well, per the rules it DOES have to do with target's mass & detecting the gravity field of an object. Hence the name and its ability to plot an internal density map. It is explicitly NOT an active sensor. No assumptions on my part.

"Densitometer: An outgrowth of gravitic technology, a densitometer can scan an area and plot variable densities, effectively creating a three-dimensional map of all objects."

 

[Nerhesi]

That makes the assumption that a Densitometer range has anything to do with the mass of the target.

Well, per the rules it DOES have to do with target's mass & detecting the gravity field of an object. Hence the name and its ability to plot an internal density map. It is explicitly NOT an active sensor. No assumptions on my part.

"Densitometer: An outgrowth of gravitic technology, a densitometer can scan an area and plot variable densities, effectively creating a three-dimensional map of all objects."

Which doesn't, in any way mean that there is no hard cut off. At that point, it doesn't matter the scale/size of your target, you will simply not get any information/detect it. Fiat it however you want, but there is nothing unreasonable by how a Densitometer supposedly works - regardless of active or passive nature.

 

[sideranautae]

Which doesn't, in any way mean that there is no hard cut off. At that point, it doesn't matter the scale/size of your target,

Well, since it works on detecting gravity (passively) as a force which follows the inverse square law (maybe it could be tidal so inverse cube). Like light, it DOES mean that there is no hard cut off point.

If your telescope can detect light down to the strength of 1 lumen (as measured at the lens) it matters not that the light originated 1 km away or 1 light year away. How would the detector know how far away so it could stop detecting?

Do you have a line of scientific reasoning you are following on this?

 

[sideranautae]

Now we know how the IISS issues highly accurate astrogation data to the civilian market so they never run into any gravitationally significant objects between star systems while in Jump.

 

[Reynard]

Jump space isn't real space so the declaration is irrelevant.

Our world sucks at finding small objects at great range considering it has to be a whopping huge terran or a gas giant. The science and physics of a Traveller universe has it's limitations too. A technological device isn't always built to be infinitely powerful at low power or size. We normally don't see the Incredibly Huge Detection Arrays in the vast majority of Traveller scenarios or campaigns which, over great amounts of time, can get a better handle than a hand held or ship system. Heck, we have to move the Earth halfway across its orbit to calculate star distances.

 

[sideranautae]

Jump space isn't real space so the declaration is irrelevant.

See rule on jumping within 100D limit.

Our world sucks at finding small objects at great range considering it has to be a whopping huge terran or a gas giant.

The question is about a defined item in the rules. Maybe I misstated. I'm not looking for alternate house rules but how to use the RAW for detecting larger objects and input about the mass I assumed for ships.

 

[Matt Wilson]

In a more detailed rule system, small craft would probably have their own detection ranges, and you might even have a range column in there that could tell you how far away you could detect a character in a space suit. As it is, the table lumps together 10dt small craft and 2000 dt freighters. If you use either end of that range you'll get some weird numbers when you scale up.

If you a) apply the inverse square law and b) use a number somewhere in the middle of the CRB ship sizes, the range at which you can detect a moon comes out to a small fraction of a light year. I can live with that kind of range. Dedicated arrays would be better, but IMTU starships would mostly be system-limited.

 

[Reynard]

"See rule on jumping within 100D limit."

And you're right about that. So much to remember. I was remembering the subsequent line that the Jump drive 'creates' a parallel universe.

Yet the Astrogation task is easy so there must not be a lot of X factors out there. One thing about the Traveller universe, there are little to no brown dwarves or rogue worlds running interference between the uber vast open space between systems.

Traveller is commonly set up in highly explored and civilized space explaining the Easy task. Other regions without extensive exploration or wilderness should have greater difficulty Astrogation task reflecting only macro information from long ranged observation. This is what makes the various scouting services invaluable. Reading over the scout procedures, densitometers don't come into play until a system is reached so they are definitely not very powerful even at ship scale.

As I mentioned earlier, there are probably detection systems that are HUGE so are either mounted on dedicated station or planet bound. Still, it takes a lot of time to gather and process the information and even them, if anything like the real world, a lot gets missed. It's more guessing about interstellar matter.

 

[sideranautae]

If you a) apply the inverse square law and b) use a number somewhere in the middle of the CRB ship sizes, the range at which you can detect a moon comes out to a small fraction of a light year. I can live with that kind of range. Dedicated arrays would be better, but IMTU starships would mostly be system-limited.

So maybe a 10,000 ton ship as the baseline? (moves the 176 ly figure to .176 ly) Generating a range table for different sized ships is just a simple spreadsheet away. Even easier if size classes are used.

Thanks.

 

[sideranautae]

So, these are the tables derived based on a ~50,000 ton ship:

Next I'll work up Passive IR sensor range tables.