Science transmission relation to signal strength

[VMQ]

I was reading the wiki pages about CommNet https://wiki.kerbalspaceprogram.com/wiki/CommNet to figure out what science transmission to expect for various signal strengths, but it only give a nebulous answer: "This bonus decreases non-linearly with signal strength." Googling this also didn't turn out anything, so I thought it is probably straight forward to "beam" a vessel to various distances to Kerbin and take some data about this relationship. The CommNet page describes the signal strength vs distance, so I started sending a vessel with a Communotron 16 out into space. With a Tracking Station with 250G the maximum range is 353.55Mm. With this the signal strength is calculated. (See wiki for formula).

Procedure: Use <Ctrl><Alt>-F12 and set craft in Sun orbit. Select Kerbin as target. Place test craft at the same angle as Kerbin: In "set orbit" set eccentricity to 0.00001 and adjust "Arg PE" (Argument of periapsis) until the target phase angle is 0 deg.  This allows to calculate the distance between Kerbin's and the craft by (Kerbin altitude) - (Craft altitude+Kerbol radius).

For the various distances I took data for signal strength, Science bonus and science transmit value for Temperature, Pressure, Mystery Goo Materials Study and Magnetometer. I also calculated the signal strength according to the wiki. The calculated signal strength agrees pretty well with the signal strength provided by the game when hovering the mouse over the signal strength icon, but can anyone explain the science bonus dependency?

See https://docs.google.com/spreadsheets/d/1G5QT6JhA4P_90pcRfA7tyPhpS1TztGEwG_LaJo9dygk/edit?usp=sharing for the complete "measurements".

Signal strength	Science bonus
0	0
1	0
7	0
21	0
41	1
45	1
46	19
47	19
48	19
48	20
49	20
53	21
58	22
62	23
63	24
64	24
64	24
65	24
66	25
70	26
74	27
78	28
79	29
81	29
81	29
81	29
81	29
81	29
82	40
82	40
82	40
85	40

 

That really is "non-linear"! Make sure to always have at least 82% signal strength!

[Streetwind]

On 2/13/2021 at 6:55 AM, VMQ said:

can anyone explain the science bonus dependency?

Not really, no. I raised this as a feedback item back when commnet was first introduced with (I think it was ) version 1.3. And I've brought it back up two or three times since then. I've gotten no reaction at all to my inquiries.

Basically: it makes no sense, and it is here to stay until the end of time