Elements of a Remote Sensor Signals, Noise, Definitions

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) Bistatic System

Detector STIMULATED Signal +Noise (1) Aperture (Antenna) Receiver (Rx) Signal Generator Transmitter(Tx) Circulator or Mixer Monostatic System

Spherical Coordinate System

Solid Geometry Steradians The solid angle of a cone with apex angle,coneapex

Energy Flux and Radiance The radiant flux, is the rate at which energy is transported toward or away from a surface, with units of watts (W). The radiant flux is called power in radar meteorology! The radiant intensity is the radiant flux per unit solid angle, with units of (W sr -1 ) and is used in the description of radiation propagating from a point source.

Energy Flux and Radiance The flux density has units of W m -2, and is the radiant flux per unit area that is either incident upon or emitted from a unit surface area. – termed “Irradiance”, in atmospheric science and oceanography – Surface radiometer measures irradiance

Energy Flux and Radiance The radiance,,has units of W m -2 sr -1 and is the radiant flux propagating toward or away from a surface in a specified direction with a solid angle. The flux is emitted from or incident upon a differential unit area inclined at an angle to the direction of energy propagation.

Emitted radiances are called RADIANCE and denoted with the symbol L Incident radiances are called BRIGHTNESS and denoted with the symbol B

Solid Angle Resolution,

Illumination Angle,

Sphere of outward propagating radiation Object with Radiant Flux, (Watts) r

Illumination Angle,

Solid Angle Resolution,