Terminology, Acronyms and Symbols
SAR Glossary
| TERM | DEFINITION |
|---|---|
| Azimuth | Direction aligned with the relative spaceborne platform velocity vector. |
| Detection | Processing step in which the phase information is removed and only the signal amplitude is preserved. Normally the detection uses a magnitude squared method and has units of voltage square per pixel. |
| Focusing | Data processing finalized to focus the SAR image in range and azimuth through bidimensional signal compression. |
| Geocoded | The data contains geographic information or coordinates corresponding to the location of the data. |
| Georeference | The internal coordinate system of the image can be related to a ground system of geographic coordinates |
| Ground range | Projection of the slant range into the ground. |
| Incidence angle | Local incidence angle on ground calculated using the ellipsoidal Earth model. |
| Looks | Image obtained using only part of the spectrum to focus the image (subaperture). It can be done in range and in azimuth, and normally is used to reduce the speckle noise from SAR images through incoherent sum (multi-look process). |
| Range | Direction orthogonal to the satellite velocity. |
| Slant range vector | Line-Of-Sight distance between the antenna and the target on ground. |
| Slant range plane | Plane containing the relative sensor velocity vector and the slant range vector for a given target. |
|Orthorectification |A subtopic of georeferencing— The process of converting images into a form suitable for maps by removing sensor motion and terrain-related geometric distortions from raw imagery. |
List of Acronyms
| TERM | DEFINITION |
|---|---|
| ASCII | American Standard Code for Information Interchange |
| BSD | Berkeley Software Distribution |
| CF | Calibration Factor |
| Cn | Coefficient ‘n’ in a polynomial |
| DC | Doppler Centroid |
| DN | Digital Number |
| ECEF | Earth-Centered, Earth-Fixed |
| GR | Ground Range |
| GRD | Ground Range Detected |
| GRSR | Ground Range to Slant Range conversion |
| HDF | Hierarchical Data Format |
| KML | Keyhole Markup Language |
| PNG | Portal Network Graphics |
| PRF | Pulse Repetition Frequency |
| RMSE | Root Mean Square Error |
| RPC | Rapid Positioning Capability (or Rational Polynomial Coefficient) |
| SR | Slant Range |
| SAR | Synthetic Aperture Radar |
| SLC | Single Look Complex |
| UTC | Coordinated Universal Time |
| VV | Polarization (Vertical transmitted and Vertical received) |
| WGS84 | World Geodetic System (1984) |
| XML | eXtensible Markup Language |