Cite as: |
Meyer, H.; Thies, B. & Bendix, J. (2011): <b>Land use/land cover map of South Ecuador 1987.</b> <i>Available online (http://www.tropicalmountainforest.org/data_pre.do?citid=1038) from DFG-FOR816dw.</i> |
Resource Description
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Associated entities to this dataset: |
Attribute Name -- Attribute Label |
Unit |
Attribute definition |
Land_use
--
land use
|
no unit |
Land use |
Method
(Sampling/processing description of the values of
this attribute by one ore more steps.)
|
--- Step
1
---
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Title
:
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Cloud mask development |
Description
:
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Training sites of clouded and unclouded areas were selected. A maximum likelihood classifier was then used for cloud classification. Since cloud edges and especially cloud shadows could not be identified in this way, they were digitized manually. |
Instrumentation:
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Instrument:
Description:
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Instrument: Idrisi
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Vendor: Clark Labs
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--- Step
2
---
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Title
:
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Atmospheric Correction (Cos(t) model) |
Description
:
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The Atmospheric correction was accomplished using the Cos(t) model (Chavez 1996) which is implemented in IDRISI (Eastman 2006). The information used for the correction could be found in the metadata of the Landsat images. |
Instrumentation:
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Instrument:
Description:
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Instrument: Idrisi
|
Vendor: Clark Labs
|
|
Citation:
|
Eastman, J
.
(2006):
IDRISI Andes guide to GIS and image processing
. Available online
(http://tropicalmountainforest.org/publications.do?citid=1037) from DFG-FOR816dw.
|
Citation:
|
Chavez, P
.
(1996):
Image-based atmospheric corrections – Revisited and improved
. Available online
(http://tropicalmountainforest.org/publications.do?citid=1036) from DFG-FOR816dw.
|
|
--- Step
3
---
|
Title
:
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Topographic correction |
Description
:
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The topographic correction was done by a statistical- empirical approach described in Eastman (2006). For this purpose, a SRTM 90m digital elevation model and metadata from the Landsat image were used. |
Instrumentation:
|
Instrument:
Description:
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Instrument: Idrisi
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Vendor: Clark Labs
|
|
Citation:
|
Eastman, J
.
(2006):
IDRISI Andes guide to GIS and image processing
. Available online
(http://tropicalmountainforest.org/publications.do?citid=1037) from DFG-FOR816dw.
|
|
--- Step
4
---
|
Title
:
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Removal of stripes |
Description
:
|
Since the first 2 channels of some images were affected by along-scan horizontal banding, a principal component analysis (PCA) was accomplished. The first 5 of 6 principal components were back calculated into the first two channels by inverse PCA. |
Instrumentation:
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Instrument:
Description:
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Instrument: Idrisi
|
Vendor: Clark Labs
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--- Step
5
---
|
Title
:
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Adaptation of reflectances |
Description
:
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A linear regression with the Landsat 1987 scene was done with each image individually. The coefficients were used for calibrating the image using the ?calibrate? module in IDRISI. This was important since there was a bias in the reflectances of the different images. |
Instrumentation:
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Instrument:
Description:
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Instrument: Idrisi
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Vendor: Clark Labs
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--- Step
6
---
|
Title
:
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Image composite creation |
Description
:
|
The 1987 image was the basis for the image composite. The cloud mask of the 1987 image which was created in step 1 was stepwise replaced by cloudfree pixels of the other images. The order of the images which were replacing the clouded pixels was:
1986/11/02; 1986/11/02; 1985/03/20; 1989/12/28; 1990/03/02; 1998/07/14; 1998/08/15; 1998/12/21. |
Instrumentation:
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Instrument:
Description:
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Instrument: Idrisi
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Vendor: Clark Labs
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--- Step
7
---
|
Title
:
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Image Splitting |
Description
:
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Since they were some image-dependent differences of reflectances in the composite, it was splitted into 12 parts for better control in the classification procedure. |
Instrumentation:
|
Instrument:
Description:
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Instrument: Idrisi
|
Vendor: Clark Labs
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--- Step
8
---
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Title
:
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Choice of training sites |
Description
:
|
Training sites of LUC were chosen for each of the 12 parts of the composite by visual interpretation and comparison to the 2001 classification (Göttlicher 2009).
Göttlicher D. (2009): Landcover classification Ecuador (10 classes). Available online (http://www.tropicalmountainforest.org
/data_pre.do?citid=704) from DFG-FOR816dw. |
Instrumentation:
|
Instrument:
Description:
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Instrument: Idrisi
|
Vendor: Clark Labs
|
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--- Step
9
---
|
Title
:
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Image classification |
Description
:
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Spectral signatures for the LUC classes Forest, Paramo, Pasture, Urban and Water were developed (Eastman 2006). A maxlike classifier was then used for supervised image classification (Eastman 2006). In order to flatten the results, a 3x3 mode filter was applied to the image. Finally the splitted image parts were merged to one image. |
Instrumentation:
|
Instrument:
Description:
|
Instrument: Idrisi
|
Vendor: Clark Labs
|
|
Citation:
|
Eastman, J
.
(2006):
IDRISI Andes guide to GIS and image processing
. Available online
(http://tropicalmountainforest.org/publications.do?citid=1037) from DFG-FOR816dw.
|
|
--- Step
10
---
|
Title
:
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Distinguishing forest from subparamo |
Description
:
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The spectral differences in the composite deriving from the different input images did not allow to distinguish between different forest types. Thus, Subparamo was distinguished from other forest types using information from the 2001 classification (Meyer et al. 2011) Under the assumption that Subparamo does not change into other forest types, forest in the 1987 classification was reclassified as Subparamo if it was Subparamo in 2001.
Meyer H. , Thies B. , and Bendix J. (2011): Land use/land cover map of South Ecuador 2001 . Available online (http://www.tropicalmountainforest.org/data_pre.do?citid=1039) from DFG-FOR816dw. |
Instrumentation:
|
Instrument:
Description:
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Instrument: Idrisi
|
Vendor: Clark Labs
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