GRD
GRD stands for Ground Range Detected and it is widely used in processed SAR (Synthetic Radar Aperture Radar) data format. Unlike raw SAR data, which requires extensive processing, GRD data has already been focused, detected & projected to ground range, making it easier to use for many applications.
GRD data preserves amplitude information of the radar backscatter & is typically multi-looked to reduce speckle noise, providing a balance between resolution & image quality. It is commonly delivered in formats such as GeoTIFF, allowing seamless integration with GIS & remote sensing software like SNAP, ENVI SARscape and QGIS.
This format is especially suitable for applications like change detection, land use mapping, environmental analysis & flood monitoring where rapid access to calibrated, map-ready SAR imagery is required.
SLC
SLC (Single Look Complex) is a raw, high-resolution SAR (Synthetic Aperture Radar) data format that preserves both amplitude and phase information of the radar signal. Unlike GRD (Ground Range Detected) data, SLC data has minimal processing, keeping the full complex signal needed for interferometric and polarimetric analyses.
SLC data is essential for advanced SAR applications such as:
- Interferometric SAR (InSAR),
- Differential InSAR (DInSAR),
- Polarimetry
- Time-series deformation studies, due to the retention of the phase information necessary to measure millimeter-scale surface changes.
Processing SLC data requires specialized software like SNAP, SARPROZ, or GAMMA, as it involves steps like co-registration, calibration, and interferogram generation. Due to its richness and precision, SLC data is the preferred choice for research and operational applications where accurate measurements of topography, surface deformation, or vegetation structure are needed.
CSI
CSI (Complex Single Image) is a SAR data product that preserves the complex radar signal from a single acquisition, containing both amplitude and phase information. This format is similar to SLC (Single Look Complex) but is typically provided for a single image scene rather than a full acquisition strip or swath.
CSI data is primarily used for advanced SAR applications, including:
interferometry, deformation monitoring, and polarimetric analysis, because it retains the critical phase information required for precise measurements. Similar to other complex SAR products, processing CSI data requires specialized software such as SNAP, GAMMA, or SARPROZ, which can perform tasks like co-registration, interferogram generation, and calibration.
This format is particularly useful for researchers and professionals who need high-precision SAR measurements without immediately working with larger multi-scene products.
VID
VID (Video Image Data) is a SAR data product designed to provide quick-look or preview images derived from raw or processed SAR acquisitions. VID data is generally low-resolution and map-projected, making it suitable for rapid inspection, scene selection, and preliminary analysis before working with higher-resolution products like SLC or GRD.
VID SAR images preserve amplitude information but typically do not retain full phase data, so they are not suitable for interferometric or polarimetric analyses. They are mainly used for visual assessment, quality checks, and rapid situational awareness. VID products are compatible with software like SNAP, ENVI SARscape, and GIS platforms, allowing users to quickly identify areas of interest for further SAR processing.