I recently chanced upon the paper Making the Invisible Visible: Precision RF-Emitter Geolocation from Space by the HawkEye 360 Pathfinder Mission (32nd Annual AIAA/USU Conference on Small Satellites) describing the Hawkeye 360 Pathfinder mission which employed a triangular formation, in the general layout of the diagram below.
Triangular Formation Layout

In the specific mission, satellite C is RAAN offset by 0.018 rad, to achieve maximum X distance at equator (collinear with A and B at maximum latitudes), while Y and Z are equidistant at 125km.

My question is why such a formation would be selected against a Projected Circular or other formation designs? Might it be because of relatively minimal J2 effects?

As a follow up, I'm wondering how the orbital elements of each satellite would be optimized in the first place (why the specific X, Y, Z distances). For Time Difference of Arrival applications, as in this mission, the wider the formation is, the better the dilution of precision. I'm guessing one of the factors in deciding against having large intersatellite distances would be the sensitivity of the payloads and maybe consideration over orbital maintenance requirements?



Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.