Sapphire - Inverse SAR (ISAR) Imaging Tool

Sapphire is an Gtk+/OpenGL based Inverse SAR (ISAR) image generation and visualization tool. Sapphire imports the lucernhammer signature file format and Xpatch .field file format and allows the user to calculate sets of SAR images from these signatures.

The user has complete control over:

Number of SAR bins
FFT Window Function
FFT Array Padding
SAR Array Interpolation
Rectangular Reformatting
Sliding or Fixed Windows for Images

Sapphire can perform aperture integration over sweeps in Elevation/Theta and/or Azimuth/Phi. The user workspace contains controls to slide through multiple sequences of ISAR images, so the user can see the image "rotate" if a sufficiently large set of angles are available.

For visualization, the user can select between:

2D and 3D visualization modes with multiple predefined colormaps
Pan, Zoom and Rotation
Automatic facet model overlay with ISAR image data
Multiple loaded SAR data sets

Sapphire has both binary and ASCII SAR data file formats, making it possible to use these data files in other tools very easy.

Executables of Sapphire are supplied for the Win32 platform only. The source code may be used to compile it on other platforms such as Linux and IRIX. This is because the Gtk+ libraries change far too often for us to distribute dynamically linked binaries. The source code should make it easy for the seasoned user to easily modify and extend the tool to incorporate custom ISAR calculation algorithms. Sapphire has been compiled and verified to operate on Intel Linux and SGI IRIX machines with the appropriate Gtk+ libraries.

Fieldian has been updated to calculate the same SAR data sets from the command line, so many SAR images can be calculated in batch fashion without needing to use the Sapphire GUI.