Presentation on theme: "EM Wave Source Object Re-radiated EM field ???. GeneratorTransmission Line Dipole Antenna free space wave uniform traveling wave reflected traveling wave."— Presentation transcript:
EM Wave Source Object Re-radiated EM field ???
GeneratorTransmission Line Dipole Antenna free space wave uniform traveling wave reflected traveling wave Continuous Energy Density (Standing Wave)
Power Density decreased in this region due to reflection from parabaloid. Reflective Parabaloid
Detector Aperture (Antenna) Receiver (Rx) Signal Generator Transmitter(Tx) Bistatic System Object
Detector Signal post-conditioning to enable detection (sampling and averaging) Signal preconditioning to enable detection (change frequency, amplitude, etc.) Signal +Noise (1) Electronic Noise (2) Aperture (Antenna) Receiver (Rx)
Detector STIMULATED Signal +Noise (1) Aperture (Antenna) Receiver (Rx) Signal Generator Transmitter(Tx) Circulator or Mixer Monostatic System
Radar Basics: Pulses and Range Gates Transmitted Pulse Noiseless Receiver Ln P r Time
Signals and Noise Transmitted Pulse Observed Signal (target echo plus noise) Ln P r Time
Signal Averaging and Detection Transmitted Pulse Observed Signal plus noise After Signal Averaging (target echo plus noise) Ln P r Time
The Radar “Bright” Band
Multiple “Bright” Bands
Steradians A Radian "cuts out" a length of a circle's circumference equal to the radius. A Steradian* "cuts out" an area of a sphere equal to (radius) 2. *The name steradian is made up from the Greek stereos for "solid" and radian. The SI Unit abbreviation is "sr". Sphere vs Steradian The surface area of a sphere is 4πr 2. The surface area of a steradian is just r 2. So a sphere measures 4π steradians, or about steradians. Likewise a steradian is 1/12.57, or about 8% of a sphere.