HYPERCAM LWIR dataset description

The provided HyperCam dataset is a datacube from the IMAGETNA campaign which corresponds to the measurement of 26 June 2015 at 08:25:44 UTC. The calibrated data from “Reveal Pro 5” software has been converted into an ASCII file containing the wavenumber values and the associated radiance and brightness temperature values for each pixel of the image.  The image is composed of 20 480 pixels (i.e. 320 pixels along the horizontal axis ⨯ 64 pixels along the vertical axis) with a spectral resolution of 2 cm-1. All the metadata of the datacube are summarized in a file available on HEMERA datacenter along with the datacube.

Characteristics of the HyperCam datacube

  • Name of the datacube file : dataHC_20150626_082544805.dat
  • Broadband image:
  • Time of measurement : 26 June 2015 at 08:25:44 UTC
  • Location :
    • Mount Etna Pizzi de Neri Observatory
    • 37°45’56.8″N – 15°00’59.7″E
    • Altitude : 2,850m
  • Characteristics of the sequence :
Spectral resolutionTemporal & spatial resolution FOV Spectral range Angle to the horizon
1.66 cm-12.547 s 320 ⨯ 64 pixels25.6 ⨯ 5.1°879 – 1314 cm-115°

The ILS (instrumental line shape) is a pure cardinal sinus with a width at mid-height of 2.016 cm-1

  • Datacube data format:

The raw HyperCam data file has been converted into an ASCII file composed of a header of 5 lines followed by 5 columns of numbers.

Figure 1: Screenshot of the first lines of the datafileDatacube data format:

The 5 lines of the header correspond to:

  • Line 1: Number of horizontal pixels
  • Line 2: Number of vertical pixels
  • Line 3: Number of spectral points
  • Line 4: IFOV value along horizontal axis (in rad)
  • Line 5: IFOV value along vertical axis (in rad)

The 5 columns of numbers correspond to:

  • Column 1: Index of the horizontal pixel (from 1 to 320)
  • Column 2: Index of the vertical pixel (from 1 to 64)
  • Column 3: Wavenumber (in cm-1)
  • Column 4: Brightness temperature (in K)
  • Column 5: Radiance (in W/(m².sr.cm-1))

The data are listed following the scheme:

Figure 2 – Scheme of the data listing

→ Note that the pixel 1 – 1 is the bottom right pixel of the image below and the pixel 320 – 64 is the top left pixel.

  • Contacts

For questions about the data or to get other datafiles from the Imagetna campaign, please contact

Nathalie Huret: n.huret@opgc.fr
Sébastien Payan : sebastien.payan@sorbonne-universite.fr