We are thrilled to announce the availability of a new “parameter verification step” for the GEP P-SBAS service. This feature is automatically invoked at the launch of a new P-SBAS processing job. It is implementing a number of constraints to be respected for the selection of P-SBAS input parameters, up to now only described in the P-SBAS Processing tutorial.
This new Platform feature is expected to significantly improve the GEP user experience and user satisfaction, with two obvious advantages:
- a drastic reduction in the rate of failed P-SBAS jobs because of wrongly defined parameters,
- and an easy, very interactive way to learn about how to use a processing service.
Other GEP processing services will soon benefit from this capability.
Once the service parameters have been entered in the input fields, they are submitted to the parameter verification service by activating the “Run job” action. Automated checks are then performed within a few seconds, to verify their correctness and validity ranges.
If the input parameters are checked as correct, the Job will be instantiated and will start running.
If a parameter does not comply with the expected syntax and/or authorised value ranges, a warning message (a text message printed in red) providing an appropriate guidance will be displayed under the wrong parameter field. The user is then invited to make the recommended changes, and to submit again the Job definition for a new verification prior to running it.
The checks that are currently carried out on the P-SBAS parameters are the following (we are still working to make this list evolve further):
- The input references supported
- Minimum number of Sentinel-1 SLC input references
- Acquisition dates of the Sentinel-1 SLC input references
- Swath Identifier of the Sentinel-1 SLC (level 1) input references
- Location of the reference point
- Definition of the reference point
- Definition of the Temporal Coherence Threshold
A specific error message, providing a hint on the way to correct the identified issue, is associated with each of the checks being carried out.
We provide below a few examples of the error detections and related user guidance that can be generated.
- Use point instead of comma for the floating point separator
Value out of range:
The value of the Temporal Coherence of each point must be set in the range 0.7-0.9
The reference point must be located inside the defined Area of interest
Make sure the acquisition date of this scene is no more than one year away from any other acquisition date
The minimum number of input references must be greater than or equal to 20
Wrong data type:
The only input references supported are the Sentinel-1 SLC (level 1)
The swath Identifier of the Sentinel-1 SLC (level 1) input references must be IW
If there are several errors detected at the same time, the warning messages with their user guidance will be displayed on each of their respective input fields.
This automated mechanism will significantly reduce the rate of failed P-SBAS jobs because of wrongly defined parameters.
We’ll continue over the coming weeks and months to improve this parameter verification step, for example with more checks related to the constraints applicable to the selection of the Sentinel-1 inputs.