Hyperspectral Data Processing

How to orthorectify Headwall Nano data collected by a Phoenix LiDAR System in Headwall's SpectralView software.

circle-info

Phoenix LiDAR Systems store Headwall Nano data slightly differently than payloads from other integrators. This document explains the necessary workflow for utilizing PLS data in Headwall's software.

Input Data

  • SBET format post-processed trajectory

    • This is required for georeferencing the Nano Hyperspectral imagery.

    • Utilize NavLab (Cloud or Embedded) or alternatively Novatel's InertialExplorer to produce an SBET .out file

  • DEM

    • DEM files must have a geographic projection, such as WGS84 EPSG:4326, that matches the processed SBET datum

    • The best source for a digital elevation model is from co-acquired LiDAR data.

      • After achieving an accurate ground classified point cloud in SpatialExplorer, use the Create Maps tool to output a Geodetic Elevation raster .tif file.

    • Other DEM sources can also be used.

  • Hyperspectral Imagery

    • It is highly recommended that users Reformat Headwall data in SpatialExplorer before proceeding to SpectralView

SpectralView

  • Place a copy of your project DEM raster into the "dem" folder that is located in the Headwall software install directory

    • Similar to "C:\Headwall\dem"

  • Place a copy of your SBET .out file in the same directory as your reformatted Headwall data

  • Open a hyperspectral data cube in SpectraView.

circle-info

Other steps, such as Radiance and Reflectance computation, may be taken prior to orthorectification in SpectralView

  • Click the "Ortho R." tool and configure the orthorectification settings.

    • Enable "Advanced settings..."

      • Set "Time offset (ms)" to -18000 to account for GPS leap seconds

      • Check "Use post process file"

    • All other settings are sensor specific.

Example Ortho Rectification Settings
  • Click "Start O.R" and ensure that the results displayed on the Preview tab look satisfactory.

  • Select all of the wavelengths that you would like output on the Create tab and then press "Create Cube"

Last updated