A Model for Radar and Jammer Detection

The Model

Based on game version

I have created a Desmos Graph Model that is able to make predictions on when a ship should show up as a track on radar. This helps turn the math on the Wiki into a toy you can tinker with to help understand how radar and jamming works in Nebulous. Let me know if its broken or predicting results that don't match gameplay.

V 1.1

- Added Toggle for target to be radar/comms on or off, will apply percentage reduction in signature

Gain (dBm) as a function of Radar Signature (m^2) and Distance (m)[www.desmos.com]

NOTE: You can edit the graph as you please, the site will generate a unique URL for any changes you make so you can not hurt it! Make your own, play with it, save it. It is for you!

- How to Use -

A section on the graph includes steps on how to use, expand that folder.

This Model considers a single ship vs a single target ship.

You input the Distance from you to the target, the # of Adaptive Radar Receivers on your ship, the # of jammers against you on the target ship. The distance slider also configures the jammer distance since this is a two ship model only.

You slide the distance (d1) slider to adjust the vertical line of your radar of interest (red blue green) with a ships signature of interest (x-axis) and read off the distance value (d1) you selected, that is when the ship should become visible as a Track or TRK in game. Signatures left of the vertical line are not seen and any to the right will be seen. Use the Reference Signature slider to mark an x-axis value for reference.

The Triangles on the graph are buttons to quickly select distance values and turn on boost mode (burn through) for the parallax and frontline radar type.

- A Note on Accuracy -

We allow for +- 500 m deviation since we have to guess the signature of the target ship. in general, slanted ships are on the left 1/3 section of the shaded reference regions on my graph, and the right 2/3 is for worst cases where the ships cardinal directions are facing the radar. Check out the Wiki link below to help guess/estimate the signature.

Nebulous Wiki : Hulls[nebfltcom.wikidot.com]

The model is not perfect but it is making predictions that are good. To be a good result, the actual result in game should be around 500 m of the prediction. Since it is hard to tell what the radar cross section of a ship will be since we have to guess by using the wiki radar cross section models and observing the angle in game.

- Other Notes -

I based all the math on the equations I found on the Wiki. The equations can be found on the graph left side if you want to see them and dig down into it.

Wiki Radar Section[nebfltcom.wikidot.com]

The Idea with my model is that the curved red, blue and green lines are the radar energy returns in dBm's for a particular radar at a signature (x-axis) and distance (d1). If a point on that line is above the radars sensitivity value or noise floor (orange dot line) then the target shows on radar as a TRK. The orange dots will intersect with the particular radars vertical dashed line(s) and the gain curve if it applies to one radar type.

Note: After testing with no jammers and 1 or more ARR I conclude that what is remarked in the Radar section of the wiki is true, any radar return under the minimum noise energy of 1*10^-7 is invisible, this is equivalent to -40 dBm. 1 ARR is enough to achieve this optimal state, more ARR will only improve detection performance under jamming with extra noise filtering.

A dBm of -40 is a hard floor and nothing will show up on radar below that. So by adding an ARR you can not improve your radars effective sensitivity beyond -40 dBm despite what it says in fleet manager.

Note: adding Jammers will cause up to 3 orange lines to appear that represent the new noise floor for a particular radar type. Look to the point of intercept with the vertical line and gain line to mark the minimum signature that can be read for the selected distance and other parameters for that radar. My Tests with a single jammer indicate good predictions.

Note: I think that the parallax radar does not actually boost to 12x in the game and so this model is using an 8x boost so that the real results match my model.

Note: Over 10 km the jammer effect goes away since that is the max range of the blanket jammer. A Spyglass radar advantage is that it may be able to see a jammer ship before it is in range to jam the spyglass.

Youtube Videos

Check out my inspiration for doing this math stuff.

This video's results can be used to verify my model's predictions (no jammers).

JDee has many excellent tutorials on the game.

JDee - Radar Part 2

Source: https://steamcommunity.com/sharedfiles/filedetails/?id=2805658436					

More NEBULOUS: Fleet Command guilds