Working with the Data
Opening the Files
HICO files are compatible with ENVITM software. With some scripting, they can also be opened using programming languages such as Fortran, IDLTM, and MATLAB®, and in atmospheric correction programs such as Tafkaa (NRL), ATREM (Atmospheric Removal Program, University of Colorado), and FLAASH (Fast Line-of-Sight Atmospheric Analysis of Spectral Hypercubes).
General File Properties
The data are stored in binary files with an interleave format of either BIL (band interleaved by line) or BSQ (band sequential). These interleaves describe the order in which multi-dimensional data are stored within the file.
Information describing the HICO data file format is contained in an ASCII header (*.hdr) file accompanying each data file. When opening a data file in ENVI software, the software automatically reads the information from the appropriate header file. For other software, header parsers will need to be custom written to extract the necessary information. For more information, see the Header Files section of the Data Characteristics page.
For detailed information about the contents and format of HICO files see the Data Characteristics page.
Scaling the Data
The user must apply a scale factor to the data to transform them to appropriate units before use.
Using ENVI software
Every data file (*.bil or *.bsq) has an accompanying header file (*.hdr) required by the ENVI program. These header files must be in the same folder as the data files.
- Launch the ENVI software.
- To load a HICO *.bil or *.bsq file, use File > Open Image File from the main menu.
- The Available Bands List will open - choose the band(s) of interest. Click on the Load Band button to display the image.
Using MATLAB programming language
Sample code is available demonstrating how to work with HICO data in the MATLAB programming language. This code loads the data from a *.hico.bil file, creates a true-color (RGB) image, and plots dark-corrected spectra from 4 user-selected pixels.
Using IDL programming language
An example program demonstrating how to load data from a HICO file in the IDL programming language is provided.
Using Fortran programming language
A code fragment illustrating one way to load HICO data using the Fortran programming language is provided. This piece of code is based on Fortran 90.
1 Software products listed on this webpage are not meant to imply endorsement by the HICO team or the Office of Naval Research. The products named are provided only as examples of software that may be used.