@inproceedings{nkg2026,
  title = {Regional Covariance Model and Chrono-Geoid Determination Using Least-Squares Collocation in Finland},
  author = {Lecomte, Hugo and Bilker-Koivula, Mirjam},
  booktitle = {NKG General Assembly 2026},
  year = {2026},
  month = {09},
  note = {(poster)},
  url = {},
  abstract = {Chronometric geodesy exploits the gravitational redshift of optical atomic clocks to measure gravity potential differences at fractional frequency levels approaching 10⁻¹⁸, corresponding to a geopotential height measurement of approximately one centimeter. Combined with terrestrial gravimetry, clock-based observations offer a constraint on the long-wavelength components of the gravity field for geoid determination. It complements classical geodetic techniques for vertical reference frame determination.\nWe investigate the integration of synthetic clock-based measurements of potential differences into regional geoid estimation over Finland using Least-Squares Collocation (LSC). Covariance model functions are adjusted to describe the stochastic behaviors of the potential and its derivate, the gravity disturbance. We assess the performance of LSC over a flat region representative of southern Finland. We follow a simulation-based approach in which a high-resolution synthetic reference gravity field is constructed from a global geopotential model complemented by local data. Synthetic observations of gravity disturbances and clock potential differences are sampled at realistic locations with instrument-consistent noise, and the disturbing potential is recovered via LSC within a remove-compute-restore framework.}
}