Spectra input/output

When spectra are read from a Specpr, text, or Exel Spreadsheet file, they are transformed into a common internal tabular format that is accessible to the Hyperspectral Analysis Package programs. This tabular format consists of a set of recognized fields that are used in data processing and any number of additional fields that simply hold unrecognized input data so that they are available for output.

The recognized fields are:

Target scene target name
Quantity name of the radiometric quantity represented by the spectral measurement values
Source_File for image-derived spectra, the name of the file containing the image data set from which the spectrum was extracted
ROI_File the name of the file containing the image region of interest from which the spectrum was derived
ROI the raster location of the ROI from which the spectrum was derived
m###_### measurement value as a function wavelength in nanometres, where ###_### is evaluated to a wavelength value, "_" representing the decimal point
q###_### quality, where ###_### is evaluated to a wavelength value, "_" representing the decimal point

There is a m###_### and a q###_### field for each sampled wavelength.

The values in the Quantity fields may be one of uncal (uncalibrated, or non-transformed, "raw" values), adj_no_units, apprad, scrad, scirrad, and refl. Except for uncal, the same values are used for radiometric quantity in the image metadata, and are explained at Image metadata support.

The values in the q###_### fields may be one of plot, bmask, mask, and skip. The same values are used for bqnd quality in the image metadata, and are explained at Image metadata support.

If the input spectra do not include quality information, then a q###_### field is created for each m###_### and evaluated with plot. The Source_File, ROI_File, and ROI fields are optional, and are only used for image-derived spectra. The other fields are always used.