Hourglass Effect is listed as a radar phenomenon alongside which topics?

• A. SPOKING and SECTORING
• B. Echo Averaging and Auto Tune
• C. Interference Rejection and Antenna Misalignment
• D. Pulse Width and Range Scale

Answer: (A)

The thing being tested is recognizing a radar display artifact that comes from how the radar’s scanning and plotting work, not from a real object. The hourglass effect sits with other display artifacts like spoking and sectoring because all three arise from the geometry and timing of how echoes are sampled and drawn on the screen.

Spoking shows up as radial lines on the display due to the way successive azimuth samples are stitched into a track. Sectoring occurs when the radar’s coverage is limited to a defined sector, which can create distinctive edge-related shapes. The hourglass effect emerges when the combination of range and bearing sampling, along with the timing of sweeps, causes the plotted target representation to take on two converging limbs that resemble an hourglass. These patterns can mislead if treated as real targets, so recognizing them as display artifacts is key.