Free helix software for linux

Radar Tools in short RAT is a small collection of tools for processing SAR (synthetic aperture radar) remote sensing data, packed together in a nice graphical user interface.
Our motivation to start the development of RAT is that modern remote sensing software like Erdas Image or ENVI include only some basic SAR functionality. Advanced algorithms have to be implemented by oneself.
So we descided to start the development of RAT. RAT should bring modern SAR algorithms to a wider user-base by simplifying in particular the data handling and processing of complex SAR data.
RAT is planned as an ongoing community effort, i.e. there will be no final version with a certain functionality. It is our idea to include more and more SAR tools in future and to make them freely available to the scientific community.
We of course also hope for external contributions. Because of this, the programming interface of RAT is kept quite simple and adding own functions is quite easy. Function templates are included in the distribution and a step-by-step description of how to program a RAT module will appear soon in the documentation.
Main features:
General features
- Cross-platform (Unix, Windows, Linux & Mac OSX)
- Free software, no commercial software license needed (when using the IDL-VM version)
- Availability of the complete source code
- Modular design, easy to extend by own functions
- Small memory footprint even when processing large images (vertical tiling)
- No limitation on the image size
- Keep track of data representation changes during image processing
- Optimised preview on screen while calculations are done in full resolution
- Native import routines for E-SAR (DLR) and ENVISAT-IMS (ESA) data
- Export possibility to generic graphic formats (png, jpg & tiff)
- Undo function for the last processing step
Generic image manipulation
- Resize, presumming & cut region
- Zooming of an area of interest
- Mirror vertical and horizontal
- Binary transforms
Single channel SAR
- SAR speckle filtering (Boxcar, Median, Gauss, Kuan, Frost, MAP Lee, refined Lee, Lee-Sigma)
- Edge detection (RoA, MSP-RoA, Sobel, Roberts)
- Co-occurance texture features, variation coefficient
- Point and distributed target analysis
- Generic slant-to-ground range projection
SAR polarimetry
- Polarimetric point target analysis
- Polarimetric speckle filtering (Boxcar, Lee, refined Lee)
- Polarimetric CFSAR edge detection
- Calculation of interchannel ratios, correlation & phase differences
- Formation of covariance and coherency matrix, span calculation
- Polarimetric basis transforms (linear -> circular ....)
- Decompositions (Pauli, Freman-Durdan, Moriyama, Entropy/Alpha, Eigenvalue, Sphere-Diplane-Helix....)
- Polarimetric classification (Entropy/Alpha/Anisotropy, Wishart, No. of scatterers, physical, Lee category preserving...)
- Polarimetric calibration: imbalance, symmetrisation & crosstalk (Quegan method)
SAR interferometry
- Image pair coregistration (coarse, subpixel & spatially varying)
- Interferogram formation
- Flat-earth removal
- Phase-unwrapping (least-squares only)
- Phase noise filter (Boxcar, Goldstein & GLSME)
- Coherence estimation (Boxcar, Gauss, Region Growing)
- Shaded relief calculation
Polarimetric SAR interferometry
- Formation of POLINSAR covariance and coherency matrices
- Coherence estimation & optimisation
- Extraction of optimised ESPRIT phases
- POLINSAR speckle filtering (Boxcar, Gauss & Lee)
- Coherence analysis in the complex unitary plane