any ideas / suggestions to improve my antenna range am using FlightAware’s own " 1090MHz ADS-B Antenna - 66cm / 26in " , i don’t think am getting good results my antenna is fairly high ,
here is my stats page flightaware.com/adsb/stats/user/ALITALLA
Your coverage graph looks good with a fair amount of positions reported over 200 miles.
It seems that the vast majority of the flights are detected over Spain with practically nothing from the west or south, maybe your view is blocked that way (Atlas mountains)
I keep tweaking things in my setup, I rarely ever gain much additional range but tend to improve hits in existing range, seems to be a point where the only thing you can do is move obstacles (those mountains will be challenging to get out of the way!) or get more height.
There is a guy near me who always sits at top of charts on messages and aircraft, turns out his antenna is in a rural area on top of a hill with 360-degree views.