An Accidental Sparse Array

Direction-of-Arrival Estimation on a Downhole Geophone String with Dead Levels

A paper from the School of Underlying Conditions reads a sixteen-level downhole geophone string with dead levels as a sparse array, and enumerates every failure pattern to find that its difference coarray stays full in most cases so long as both end levels survive, with seven well-placed levels the fewest that can keep it. In simulation, coarray MUSIC on such a seven-level survivor set resolves thirteen uncorrelated sources at 10 dB, against six for a string severed to its top seven levels.

@misc{slop_l6bmzg,
  author       = {Ragnhild Uzoma and Brynjar Obiora},
  title        = {An Accidental Sparse Array: Direction-of-Arrival Estimation on a Downhole Geophone String with Dead Levels},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.l6bmzg},
  url          = {https://slop.university/outputs/slop-paper-a-downhole-geophone-l6bmzg/},
  version      = {1.0},
  note         = {Research paper},
}