152
temporary flooding occurs in winter. This plant community is dominated by Erica
scoparia, Erica ciliaris, Calluna vulgaris, Ulex minor, Myrtus communis and Cistus
salvifolius. The so-called Monte Intermedio (Mesic sites) is located on the slopes of
the dune ridges with a transitional water table depth and no surface flooding. The
community is dominated by Halimium halimifolium and Ulex australis. The spatial
distribution of scrubland is determined, at all scales, by the rolling topography that
modulates the groundwater level (Muñoz-Reinoso and Novo 2005).
INTA AHS System
The Spanish National Institute for Aerospace Technology (INTA) owns and operates the Airborne Hyperspectral Scanner (AHS) (De Miguel et al. 2014). AHS is an
airborne line-scanner imaging spectrometer manufactured by ArgonST (formerly
Sensytech Inc.) that covers spectra from 0.45 to 12.8 microns inside atmospheric
windows with 80 bands. It is installed onboard the INTA’s aircraft (CASA C-212)
and is integrated with INS/GPS Applanix POS-AV 414. A calibration and navigation equipment, an auxiliary ground instrumentation and a specific Processing and
Archiving Facility (PAF) together form the INTA AHS system. INTA offers this
system as a technological service to public institutions or commercial companies,
and has performed more than 60 flight campaigns since 2004. The main characteristics of AHS are provided in Table 1.
AHS is considered to be a “generalized” type of sensor that acquires in all atmospheric windows of the optic spectral region. The FWHM in the SWIR region is
15 nm, but 30 nm in the VNIR. As the VNIR region is important for vegetation
studies, we carried out a study on the AHS mapping capacity prior to the mapping
(Jimenez et al. 2007) showing that the AHS has sufficient radiometric and special
resolving power to map Doñana’s shrub species.
Table 1 The main characteristics of the AHS sensor
PORT
Spectral coverage (μm)
n° of bands/FWHM (nm)
λ/Δλ (minimum)
Port 1
0.43 > 1.03
20/28
16
Port 2A
1.55 > 1.75
1/200
8
Port 2
2.0 > 2.54
42/13
150
Port 3
3.3 > 5.4
7/300
11
Port 4
8.2 > 12.7
10/400
20
FOV/IFOV: 90°/2.5 mrad
Scan rates: 12.5, 18.75, 25, 35 revolutions per second (pixel 7 to 2 m)
Digitization precision: 12 bits to sample the analog signal, with gain level from ×0.25 to ×10
Two controllable thermal black bodies within the field of view
M. Jiménez and R. Díaz-Delgado
temporary flooding occurs in winter. This plant community is dominated by Erica
scoparia, Erica ciliaris, Calluna vulgaris, Ulex minor, Myrtus communis and Cistus
salvifolius. The so-called Monte Intermedio (Mesic sites) is located on the slopes of
the dune ridges with a transitional water table depth and no surface flooding. The
community is dominated by Halimium halimifolium and Ulex australis. The spatial
distribution of scrubland is determined, at all scales, by the rolling topography that
modulates the groundwater level (Muñoz-Reinoso and Novo 2005).
INTA AHS System
The Spanish National Institute for Aerospace Technology (INTA) owns and operates the Airborne Hyperspectral Scanner (AHS) (De Miguel et al. 2014). AHS is an
airborne line-scanner imaging spectrometer manufactured by ArgonST (formerly
Sensytech Inc.) that covers spectra from 0.45 to 12.8 microns inside atmospheric
windows with 80 bands. It is installed onboard the INTA’s aircraft (CASA C-212)
and is integrated with INS/GPS Applanix POS-AV 414. A calibration and navigation equipment, an auxiliary ground instrumentation and a specific Processing and
Archiving Facility (PAF) together form the INTA AHS system. INTA offers this
system as a technological service to public institutions or commercial companies,
and has performed more than 60 flight campaigns since 2004. The main characteristics of AHS are provided in Table 1.
AHS is considered to be a “generalized” type of sensor that acquires in all atmospheric windows of the optic spectral region. The FWHM in the SWIR region is
15 nm, but 30 nm in the VNIR. As the VNIR region is important for vegetation
studies, we carried out a study on the AHS mapping capacity prior to the mapping
(Jimenez et al. 2007) showing that the AHS has sufficient radiometric and special
resolving power to map Doñana’s shrub species.
Table 1 The main characteristics of the AHS sensor
PORT
Spectral coverage (μm)
n° of bands/FWHM (nm)
λ/Δλ (minimum)
Port 1
0.43 > 1.03
20/28
16
Port 2A
1.55 > 1.75
1/200
8
Port 2
2.0 > 2.54
42/13
150
Port 3
3.3 > 5.4
7/300
11
Port 4
8.2 > 12.7
10/400
20
FOV/IFOV: 90°/2.5 mrad
Scan rates: 12.5, 18.75, 25, 35 revolutions per second (pixel 7 to 2 m)
Digitization precision: 12 bits to sample the analog signal, with gain level from ×0.25 to ×10
Two controllable thermal black bodies within the field of view
M. Jiménez and R. Díaz-Delgado