The best way to learn this is by playing around with different factors in the component designer and seeing how they affect the various numbers. With practice you can develop an intuition for this.

Going by the examples:

(1) Engines:

`Pratt & Whitney ID06-PW-06 Seraph Ion Drive (1) Power 60.0 Fuel Use 36.54% Signature 60.00 Explosion 7%`

- Ion Drive tech is in the name. The base EP is therefore 12.5 EP/HS.
- Explosion change is the engine power modifier (as a percentage) divided by 10 and rounded down. In this case, 7% explosion chance will indicate a 70% or 75% EP modifier.
- The power (per engine) is the product of the base EP tech, the EP modifier (as a decimal), and the engine size. In this case we have two options: a 70% modifier implies a size (60 / 0.7 / 12.5) = 6.857... HS engine, which is not a possible engine size, while a 75% modifier implies a size (609 / 0.75 / 12.5) = 6.4 HS engine, which is a possible engine size and is the only remaining possibility.
- Given this, the only tech remaining to figure out is fuel efficiency, which you can determine from either (a) trial and error, or (b) checking the fuel use with the base 1.0 efficiency and then dividing the listed fuel use by that base value to get the actual fuel efficiency tech. In this case, with 1.0 fuel efficiency I find a fuel use of 60.89%, so calculating (36.54 / 60.89) = 0.6 gives the fuel efficiency tech used.
- This assumes no thermal reduction technology was used (which is correct in this case). Thermal reduction tech level can be read by dividing the listed signature by the listed power, otherwise the analysis is the same as above.

(2) Active Sensors:

`Artemis-70 Active Sensor (1) GPS 12960 Range 70.8m km Resolution 120`

Active sensors use design parameters: Active Sensor Strength (STR), EM Sensor Sensitivity (SEN), Size (HS), and Resolution (RES). The resulting sensor range is:

`R = sqrt[STR * SEN * HS * RES^(2/3) / PI] million km`

- The Grav Pulse Strength (GPS) is the product of STR * RES * HS. We know the resolution already, so we can compute GPS / RES = 108.
- STR has a limited set of pre-defined values: 2 (conventional), 10, 12, 16, 21, 28, ... Therefore, we can come up with a range of possible sizes by dividing the above value by each possible STR value, in this case we have sizes of 54 (too big), 10.8, 9, 6.75, 5.143..., 3.857..., ...
- The only option here which can be built in Aurora is STR = 12, HS = 9
- You can use the range equation above to find SEN, although it is
*usually* a good guess that the SEN tech level is the same as the STR tech level in terms of research costs (especially for designs at the start of an AAR, which tend to use relatively uniform tech levels compared to designs from the middle of a game in progress). In this case, SEN = 6 is the matching tech level, and you will find that it does indeed yield R = sqrt[12 * 6 * 9 * 120^(2/3) / PI] = 70.8 million km. - Electronic hardening and ECCM do not appear in the class readout, so you'll have to guess. It can be possible to infer these values from the total build cost of the ship if you get everything else right and end up with a mismatch, though this is not a reliable method.

Miscellaneous tips:

- Remember that tech levels from AAR starts tend to be more uniform or sensible than tech levels in the middle of the game, so you can exploit this to make some assumptions.
- Make use of limited numerical options where possible, for example there are only a limited number of possible active sensor strength techs or EM sensor sensitivity techs. Many components have limited options for sizes, weapon power levels, etc.
- Be aware that players might rename components in a misleading way. For example, Steve's WH40K AARs use 10cm railguns as "Lascannons", while the name implies a laser weapon this is not the case.
- Conversely, players have tendencies that you can exploit to make guessing easier. For example, both Steve and myself tend to use engine mass fractions that make it very easy to come up with round numbers for both ship tonnage and speed, e.g. 32% or 40% of ship mass as engines.
- Some components unfortunately require only guesswork since little or no information shows up in the ship design readout. Magazines are probably the
*worst* component for this.

Finally, be aware that many ship designs from older game versions will not be reproducible in the current version of Aurora due to various changes to components over time. For example, the WH40K ship designs in Steve's Gothic Campaign or Earth Alliance AARs cannot be reproduced due to the change to make all Particle Beams a fixed size of 300 tons each, whereas the strength-4 particle beams used in those campaigns would have been 350 tons each. Another personal example: I can no longer reproduce the exact ship designs from my Duranium Legion 1.12 AAR, because the Boat Bay components have had their tonnage requirements reduced since that version.

Hope this is helpful.