So wide bars are carrier signals sent regularly by Meteor, as synchronization signals. Thanks Josef for the information!
De : email@example.com [mailto:firstname.lastname@example.org] De la part de Josef Garcia
For your understanding: Meteor always sends a carrier signal at the beginning and end of a flyover.
Figure 1: Carrier signal in the waterfall.
Figure 2: At the top of the picture, the black wide bar, that is the carrier signal.