# Initialize the Environment.
from os.path import join, split
from gbdxtools import Interface
gbdx = Interface()
tasks = []
output_location = 'ENVI/QuerySpectralIndices'
cat_id = '105001000672E000'
# Image Auto ordering task parameters
order = gbdx.Task("Auto_Ordering")
order.inputs.cat_id = cat_id
order.impersonation_allowed = True
order.persist = True
order.timeout = 36000
tasks += [order]
# Image AOP task parameters
aop = gbdx.Task("AOP_Strip_Processor")
aop.inputs.data = order.outputs.s3_location.value
aop.inputs.bands = 'MS'
aop.inputs.enable_dra = False
aop.outputs.data.persist = True
aop.outputs.data.persist_location = output_location+'/aop'
aop.timeout = 36000
tasks += [aop]
# Create a basic classification
envi_query = gbdx.Task("ENVI_QuerySpectralIndices")
envi_query.inputs.input_raster = aop.outputs.data.value
tasks += [envi_query]
workflow = gbdx.Workflow(tasks)
workflow.savedata(
envi_query.outputs.available_indices, location=output_location
)
workflow.savedata(
envi_query.outputs.task_meta_data, location=output_location
)
workflow.execute()
Inputs
The following table lists all ENVI_QuerySpectralIndices inputs.
Mandatory (optional) settings are listed as Required = True (Required = False).
Name | Required | Default | Valid Values | Description |
---|---|---|---|---|
file_types | False | N/A | string | GBDX Option. Comma seperated list of permitted file type extensions. Use this to filter input files -- Value Type: STRING[*] |
input_raster | True | N/A | See ENVIRASTER input type | Specify a raster to query for available spectral indices. -- Value Type: ENVIRASTER |
input_raster_format | False | N/A | See ENVIRASTER input type | Provide the format of the image, for example: landsat-8. -- Value Type: STRING |
input_raster_band_grouping | False | N/A | See ENVIRASTER input type | Provide the name of the band grouping to be used in the task, ie - panchromatic. -- Value Type: STRING |
input_raster_filename | False | N/A | See ENVIRASTER input type | Provide the explicit relative raster filename that ENVI will open. This overrides any file lookup in the task runner. -- Value Type: STRING |
Outputs
The following table lists all ENVI_QuerySpectralIndices outputs.
Mandatory (optional) settings are listed as Required = True (Required = False).
Name | Required | Default | Valid Values | Description |
---|---|---|---|---|
task_meta_data | False | N/A | directory | GBDX Option. Output location for task meta data such as execution log and output JSON |
available_indices | True | N/A | string | A string array with the spectral indices that can be computed for the input raster. -- Value Type: STRINGARRAY |
Output structure
The output of this task is a string port listing the available indices, based on the bands available in the image file. This port can be used to chain to another task. Alternatively, the output is written to a JSON file in the task_meta_data port, where the list can be found after the Task completes.
Issues
Additional parsing of the output list of indices is necessary before using the list as input for the ENVI Spectral Indices task.
Background
For additional background information on this task please refer to the Harris Geospatial ENVI documentation and
ENVI® Query Spectral Indices.
Contact
If you have any questions or issues with this task, please contact gbdx-support@digitalglobe.com.