Echotops for annotation on radar imagery

Currently four echotops are derived from the echotop product by the BRAS ("Bliksem Radar Animatie Scherm") display system and the display system of LVNL (Air Traffic Control of the Netherlands). It has been painstaking to harmonize the functionality of the two display systems and thus obtain the same annotated echotops. With the introduction of the new high-resolution radar imagery, new problems are foreseen as the porting of the current annotation algorithm to the high-resolution imagery is not straightforward. Therefore a new algorithm for the selection of the annotated echotops insensitive to a change of resolution is proposed in this technical report. Furthermore it is recommended to run the new algorithm at a central point close to the radar product processor and to add the selected echotops to the operational HDF5 echotop products. In this way all display systems have access to a common list of echotops for annotation on the radar imagery and possible discrepancies are avoided.