The function of HFSWR looks like ionosonde
in this paper.
Also, the validation of IRI model has been compared with a large amount of data including data from the most recent ionospheric satellites (KOMPSAT, ROCSAT and TIMED) and data from global network of ionosondes
. Several IRI teams are working on specific aspects of the IRI modeling effort including an improved representation of the topside ionosphere .
In our study, we collected data on the F2-layer critical frequency (foF2), hmF2, B0, [H.sub.m], and the total electron content (TEC) from the Chung-Li ionosonde station (24.9[degrees]N, 121.1[degrees]E) and YMSM GPS receiver (25.2[degrees]N, 121.6[degrees]E).
POLAN is widely accepted for inversion of ionograms obtained by classical ionosonde  and allowed our measurements of foF2, hmF2, B0, and [H.sub.m].
Ilma, "Modeling the IRI topside profile using scale heights from ground-based ionosonde measurements," Advances in Space Research, vol.
Figure 9 compares the range-time distribution of the number of occurrences of the ionospheric echoes detected by the CODAR-SeaSonde at DATAN (b) and observed by the Chung-Li ionosonde (a) for the period from 30 June to 31 July, 2015.
The concurrent ionospheric traces in the ionogram observed by the Chung-Li ionosonde are also employed in this study to help to identify the ionospheric echoes detected by the SeaSonde radar.
* Ionospheric data collection by means of a network of ionosondes (step 1): during this phase a 3D electron density estimate of the ionospheric volume of interest must be carried out by means of ionospheric models or by means of a network of ionosondes (Figure 2).
The ray-tracing makes use of the 3-D electron density profile, which is estimated by mean the IRI model or by a network of ionosondes. The charts are carried out off-line by a dedicated work station.
Those atmospheric changes can be tracked using satellites and radar systems called ionosondes