Elements of a Remote Sensor

1. Elements of a Remote Sensor Signals, Noise, Definitions

2. Aperture (Antenna) Receiver (Rx) Detector Signal +Noise (1) Signal preconditioning to enable detection (change frequency, amplitude, etc.) Signal post-conditioning to enable detection (sampling and averaging) Electronic Noise (2)

3. Aperture (Antenna) Receiver (Rx) Detector STIMULATED Signal +Noise (1) Transmitter(Tx) Signal Generator Bistatic System

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

6. Spherical Coordinate System

7. Solid Geometry • Steradians • The solid angle of a cone with apex angle ,

8. 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.

9. 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

11. 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.

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

14. Solid Angle Resolution,

15. Solid Angle Resolution,

16. Illumination Angle,

17. Illumination Angle, Object with Radiant Flux, (Watts) Sphere of outward propagating radiation r

18. Illumination Angle,

23. Solid Angle Resolution,