combining different types into single data structure

I want to make a good design about combining information. Suppose you
have different data types, and each may have semantically same data. I
want to merge these different  data types into a single data at run-
time. For example, sonar sensor has two internal data (bearing and
bearing_rate), and Radar has two as well (range, bearing.

struct sonar_data {
  float bearing;
  float bearing_rate;
};

struct radar_data {
       float bearing;
       float range;
};

sonar_data sd;
sd.bearing =3D 5.0f;
sd.bearing_rate =3D 0.1f;

radar_data rd;
rd.bearing =3D 3.0f;
rd.range =3D 12.0f;

I want to combine these two data into a single data structure:

data.bearing =3D 4.0f // average of sd(5.0f) and rd(3.0f)
data.bearing_rate =3D 0.1f;  // only comes from sonar_data
data.range =3D 12.0f; // only comes from radar_data


I don=92t know how to make a good design about this problem. Do you have
any template based (or other) suggestions?

Thanks in advance...

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