Full profile incoherent scatter fitting of Arecibo topside echoes

We present topside ionospheric measurements made at the Arecibo Observatory using the long pulse data inverted with a full-profile method.
Measurements of plasma density, ion composition, electron and ion temperature, and drift velocity up to 1800 km altitude are presented for 63 hour period from September 2016.
Our inversion method included several refinements introduced to improve computational efficiency and outlier resilience:
First, discretization errors caused by the chirp z-transform used in Gordeyev integral computations were reduced without increasing the number of samples in the integration, such that the incoherent scatter spectrum model is computed more efficiently and accurately.
This was achieved by modeling and removing the discretization errors --- the error model was constructed after a series of empirical tests in which the incoherent scatter spectra were computed from theory using high and low resolution transforms.
Second, long pulse (1000 µs) and shorter pulse (500 µs) returns were jointly processed to strengthen the statistic of the estimated parameters where and when both modes were available. The initial guess for full-profile inversions was provided by the estimates made with "height-by-height" analyses of the spectrograms generated from re-aligned lag profiles with reduced range mixings.
Lastly, spectrograms of multiple adjacent integration periods were fitted simultaneously, skipping the misfit contributions coming from interference contaminated spectra to improve the stability of our inversions.