Radar Timing and Geometry
A guide to pulse repetition interval, unambiguous range, radar horizon, and range resolution, with an emphasis on what each quantity limits or enables in a radar system.
Key formulas
What each quantity tells you
PRI is a timing quantity. Unambiguous range describes how far a target can be before echoes from one pulse are mistaken for another. Range resolution describes how closely two targets can sit and still be distinguished.
Radar horizon introduces geometry by setting a line-of-sight-style limit linked to height and curvature.
Common mistakes
- Confusing pulse width with pulse repetition interval.
- Assuming better resolution automatically means longer unambiguous range.
- Forgetting the factor of one half that appears in round-trip time relationships.
- Treating radar horizon as a full detection guarantee instead of a geometric limit.
Apply the topic straight away.
Pulse Repetition Interval Calculator
Use the Pulse Repetition Interval Calculator for quick pulse repetition interval estimates in RF, radar, and communications work.
Unambiguous Range Calculator
Use the Unambiguous Range Calculator for quick unambiguous range estimates in RF, radar, and communications work.
Radar Range Resolution Calculator
Use the Radar Range Resolution Calculator for quick radar range resolution estimates in RF, radar, and communications work.
Radar Horizon Calculator
Estimate the line-of-sight radar horizon from antenna height and target height using a standard engineering approximation.