Accurate quantification of ART, MART, and SIRT in ionosphere rebuilding based on TIEGCM assessment

Algebraic Reconstruction Technique (ART), Multiplicative Algebraic Reconstruction Technique (MART), and Simultaneous Iterative Reconstruction Technique (SIRT) are computational methodologies extensively utilized within the field of Computerized Ionospheric Tomography (CIT) to facilitate three-dimensional reconstruction of ionospheric morphology. However, reconstruction accuracy elicits disputes recurrently over its practical application, and people usually attribute this to incomplete and uneven coverage of the measurements. TIEGCM offers a reasonable and physical-based ionosphere background and is widely utilized in ionospheric research. We employed the TIEGCM simulations as the targeted ionosphere because the current measurements are far from reproducing the realistic ionosphere in detail. Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction. Similar to common practice, electron density distribution from International Reference Ionosphere (IRI) model outputs are used as the iterative initial value in CIT applications. Outcomings suggest that despite data coverage, iterative initial conditions also play an essential role in ionospheric reconstruction. In particular, in the longitudinal sectors where the iterative initial F2-layer height of the peak density (hmF2) differs significantly from the background ones, all three CIT methods cannot reproduce the exact background profile. When hmF2 is close but F2-layer peak density (NmF2) is different between the targeted background and initial condition, MART performs better than ART and SIRT, evidenced by the correlation coefficients of MART being above 0.97 while ART and SIRT being below 0.85. In summary, this investigation reveals the potential uncertainties in traditional CIT reconstruction, particularly when the realistic hmF2/NmF2 values differ significantly from the initial CIT conditions.