RADAR TELEMETRY IN ASTRONAUTICS

Credits: 9

Learning objectives

The course deals with radar systems in remote sensing applications, either for Earth and Planetary observation, interferometric SAR, radar altimeters and radar sounders. SAR working principles, applications and sizing of the main system parameters.
Radar interferometry, baseline, altitude estimation, estimation accuracy, baseline decorrelation, time decorrelation. Radar altimetry: pulse limited geometry, Brown model, RX-TX block diagram, estimate of surface parameters. Spaceborne radars: Sentinel-1, ALOS/PALSAR, MARSIS.

Cap. 1 - Generalities and physical principles of Remote Sensing

Remote sensing as a system, Properties of electromagnetic radiation, Sources of electromagnetic radiation, Mechanisms of interaction with matter, Remote sensing indicators, Interaction of electromagnetic radiation with the Earth's atmosphere.  Common Scattering Mechanisms. Surface Scattering. Volume Scattering.  Scattering from Hard Targets. Composite scatterers. Sea Surface Scattering.

Cap. 2 – Microwave systems

Passive systems, Active Systems, Synthetic Aperture Radar (SAR), Altimeter

Cap. 3 – Correcting and Calibrating RADAR imagery

Sources of Geometric Distortion: Layover, Relief Displacement, Foreshortening and Shadowing. Geometric Correction of Radar Imagery. Radiometric Correction of Radar Imagery: Speckle.

Cap. 4 – Interferometric & Bistatic SAR

The Importance of Phase. A Radar Interferometer – InSAR. Phase Unwrapping. Types of SAR Interferometry. Polarimetric Interferometric SAR (PolInSAR). Tomographic SAR. Analysis of Bistatic Radar. The General Bistatic Configuration. Remote Sensing Benefits of Bistatic Radar. Bistatic Scattering.

Cap. 5 – RADAR image interpretation

Analytical Complexity.  Quantitative Analysis of Radar Image Data for Thematic Mapping. Interpretation Based on Structural Models. Interferometric Coherence as a Discriminator. Some Comparative Classification Results.

Cap. 6 – Passive microwave imaging

Radiometric Brightness Temperature. Relating Microwave Emission to Surface Characteristics. Emission from Rough Surfaces. Dependence on Surface Dielectric Constant. Sea Surface .