(ΦωΦ) Catudp's blog
RTL-SDR Blog V4: Upgrade or Downgrade? – Part 3 (Turn)
The hit rate for distant aircraft on the western side has increased.
Overall performance has also improved.
First, let’s compare the polar plots.
On January 22, reception was strongly concentrated toward the south.
Very few aircraft were detected beyond the peninsula to the west.
By February 3, the shape changed.
Reception to the west became clearly visible, extending beyond the mountainous area.
This change is not random.
The antenna is installed indoors, at a mid-floor apartment window.
Reception is effectively limited to approximately 180 degrees.
To the southwest lies mountainous terrain.
To the south and southeast lies open ocean.
Previously, aircraft beyond the western peninsula were almost never detected.
The terrain and building geometry shaped the polar pattern.
The new polar shape suggests that something has changed in how weak western signals are being received.