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Species Mapping Generation
Once the surface reflectance mosaic of the study area has been generated from the
airborne imagery and endmembers have been extracted from the spectral libraries,
the plant species map can be generated. The user organization plays a key role in the
generation of this map.
• In the most widely used commercial remote sensing image processing software,
LSU algorithms are implemented by default. The hyperspectral imagery must be
prepared by reducing the number of bands by ACP or MNF, which can also be
implemented within commercial software. Likewise, endmembers must be
selected and prepared by applying the same reduction algorithms as those applied
to the imagery. The simple LSU algorithm is restricted to models in which only
one spectrum is allowed for each endmember. For this reason, this model does
not incorporate the natural variability in scene conditions (i.e., the same material
could have different spectral responses). The spectral response of a plant species
could be very variable due to the differences in its components and structure.
Thus, a spectral unmixing algorithm, such as the MESMA, is more suitable for
mapping plant species. MESMA allows the selection of multiple endmembers
for each endmember class and incorporates natural variability.
• The outcome of the LSU algorithm is fraction abundances imagery for each
introduced endmember; in our case, the fraction cover for each plant species.
Accuracy assessment is an integral part of the information extracted from
remotely sensed data, since thematic information always contains errors. The
accuracy assessment can be performed using the plant cover measurement
acquired during the field survey.
Practical Case: Mapping Shrublands Species of Doñana
National Park
Study Site
Doñana National Park (DNP) is located on the south-western coast of Spain. It is
one of the most important wetlands in Europe (García Novo and Marín Cabrera
2005), and was recognized as a UNESCO World Heritage Site in 1995. The climate
at Doñana is Mediterranean sub-humid and has a well-defined seasonality, with
mild and wet winters and dry and hot summers. The mean annual precipitation is
550 mm, with rainfall displaying a sharp seasonality, being mostly concentrated
between October and March (wet season) and almost absent between June and
August (dry season). Three main ecosystems have been traditionally been distinguished in DNP: inland marshes, mobile sand dunes, and stabilised sand dunes.
This study was carried out in the stabilised dunes of the Doñana Biological Reserve
(DBR), the core area of the DNP (Fig. 2).
M. Jiménez and R. Díaz-Delgado
Species Mapping Generation
Once the surface reflectance mosaic of the study area has been generated from the
airborne imagery and endmembers have been extracted from the spectral libraries,
the plant species map can be generated. The user organization plays a key role in the
generation of this map.
• In the most widely used commercial remote sensing image processing software,
LSU algorithms are implemented by default. The hyperspectral imagery must be
prepared by reducing the number of bands by ACP or MNF, which can also be
implemented within commercial software. Likewise, endmembers must be
selected and prepared by applying the same reduction algorithms as those applied
to the imagery. The simple LSU algorithm is restricted to models in which only
one spectrum is allowed for each endmember. For this reason, this model does
not incorporate the natural variability in scene conditions (i.e., the same material
could have different spectral responses). The spectral response of a plant species
could be very variable due to the differences in its components and structure.
Thus, a spectral unmixing algorithm, such as the MESMA, is more suitable for
mapping plant species. MESMA allows the selection of multiple endmembers
for each endmember class and incorporates natural variability.
• The outcome of the LSU algorithm is fraction abundances imagery for each
introduced endmember; in our case, the fraction cover for each plant species.
Accuracy assessment is an integral part of the information extracted from
remotely sensed data, since thematic information always contains errors. The
accuracy assessment can be performed using the plant cover measurement
acquired during the field survey.
Practical Case: Mapping Shrublands Species of Doñana
National Park
Study Site
Doñana National Park (DNP) is located on the south-western coast of Spain. It is
one of the most important wetlands in Europe (García Novo and Marín Cabrera
2005), and was recognized as a UNESCO World Heritage Site in 1995. The climate
at Doñana is Mediterranean sub-humid and has a well-defined seasonality, with
mild and wet winters and dry and hot summers. The mean annual precipitation is
550 mm, with rainfall displaying a sharp seasonality, being mostly concentrated
between October and March (wet season) and almost absent between June and
August (dry season). Three main ecosystems have been traditionally been distinguished in DNP: inland marshes, mobile sand dunes, and stabilised sand dunes.
This study was carried out in the stabilised dunes of the Doñana Biological Reserve
(DBR), the core area of the DNP (Fig. 2).
M. Jiménez and R. Díaz-Delgado