Density assimilated reduced order state for thermospehere-ionosphere drag estimation

Data product provided along with paper - Reduced-Order Data Assimilation for Thermospheric Density Using Physics-informed SINDyc Models. The file ark_results_full_V2.h5 contains: timestamps — UT epoch of each filter step. z_filt — posterior (filtered) ROM state coefficients at each step. z_openloop — free-running ROM state coefficients (no measurement updates) for baseline comparison. window_log — per-window assimilation summary. steplog/ — per-step Kalman filter diagnostics: trace_P — trace of the posterior covariance (the A-optimal scalar). diag_P — diagonal of the posterior covariance (marginal variances of each ROM coefficient). NIS — Normalised Innovation Squared, for filter consistency checks. innov_rms — RMS of the innovation vector. n_meas — number of measurements assimilated at each step. sat_log — IDs of the satellites contributing measurements at each step. mode — filter operating mode flag. All step-indexed arrays are aligned with timestamps. Accompanying notebook and .py files are provided to support reconstruction. For sample assimilaition code, please see - https://doi.org/10.5281/zenodo.19947885