G4DAY on 10m WSPR - GDX

G4DAY (142km) was again spotted at 1104z. It seems this sort of range is possible on 10m GDX. Doppler was a very large (4Hz) suggesting aircraft reflection or even back scatter?

G4DAY is using 10W and that may help. He was -24dB S/N with me, suggesting my signal (2W) would be buried in the noise at his end. WSPR usually decodes down to about -30dB S/N.