Follow-up meeting on 04 August 2021

A meeting was held on 04/08/2021 between Emma Bland, Pasha Ponomarenko, Bill Bristow, Gareth Chisham and Kevin Sterne on the topic of accepting fitACF 3.0 as the default processing algorithm to generate fit-level data. The DAWG notified the PIs prior to the SuperDARN 2021 Workshop that a proposal for fitACF 3.0 to become the default would be made. After discussions amongst the PIs during the Workshop, Bill and Gareth provided a summary of the PI feedback to Emma, Pasha, and Kevin. During this meeting, the PI feedback was discussed and a plan was made to address it.

1. Scientific evaluation of the new fitting algorithm

What are the specific knowledge gaps that need to be filled regarding:

The PIs expressed some uncertainty about whether the lag zero phase is more strongly affected by ‘noise’ than the fitted phase.

No other specific knowledge gaps were identified, but there were some more general comments:

What information is needed to fill these knowledge gaps?

What is missing from previous analyses presented at the workshops in 2016, 2018 and 2021?

What are the criteria for evaluating this information?

(Ref: earlier statement from the PIEC: ‘we will have objective criteria as a basis for a decision to adopt the new routine’)

Conclusion: PIs currently have no common objective criteria for evaluating the fitting algorithm, and it is difficult to unanimously agree on any criteria, objective or otherwise.

Who is responsible for providing this information?

Conclusion: PIs and the DAWG share the responsibility to ensure that the outputs of fitACF are appropriate for scientific use


2. Implementation of the despecking routine in RST

The PIEC requested that the despeckle routine be added to make_fit as a non-default command line option. Emma noted that this creates a dual purpose for make_fit (fitting and filtering). The existing standalone routine that performs the despecking (fit_speck_removal) will be retained.

Action: Emma will determine whether it is feasible to add a command line option to make_fit to perform the despecking

3. Exclusion of XCF fitted parameters in fitACF3.0

What is the scientific value of the XCF fitted parameters?

Conclusion: the XCF fitted parameters have no demonstrated scientific value


General notes:

4. Use of elv_low and elv_high fields for storing other information

This was going to be addressed by the Data Standards Working Group (DSWG). The PIEC has taken over responsibility for the DSWG tasks, and this issue has been identified as a top priority. As yet, no specific PI has been given responsibility for this action.

The DAWG has already proposed a solution to this issue to the DSWG in October 2020 (link)

The DAWG specifically requested the PIEC to discuss this issue and the proposed solution in February 2021 (link)

Action: Gareth will follow up with the PIEC to decide who shall take responsibility for solving this issue.

5. Christmas Valley data from November 2018

This interval has been analysed in detail by Emma and Pasha and the main findings were (link):

The DAWG recommended blocklisting these data.

Action: No action required

6. Vertical stripes in Clyde River data for 29 May 2021

Note: This item was added after the meeting

This BOREALIS-specific issue has already been analysed and resolved (link), and the necessary corrections have been implemented in RST4.6 on 21 June 2021.

Action: No action required

  1. Pasha: Update the fitACF3.0 White Paper to include more information about why the lag zero phase should be used for calculating elevation
  2. Pasha and Emma: amalgamate the previous workshop presentations into a single easy-to-follow document
  3. Emma: write sample IDL code to perform the statistical analysis requested for evaluating the despeckling routine.
  4. Pasha: write sample IDL code to produce 2D histogram plots comparing the fitted parameters from fitACF2.5 and fitACf3.0
  5. Pasha: write sample IDL code to perform the statistical analysis requested for comparing elevation angles determined from lag zero phase and fitted phase
  6. Bill: strongly encourage the PIs to use the sample code with their own datasets and share the results with all members of the PIEC and DAWG. A deadline will be set after the sample code is provided. The DAWG can help with interpreting the results on request.
  7. Emma: determine whether it is feasible to add a command line option to make_fit to perform the despecking
  8. Pasha: provide a brief explanation why the XCF fitted parameters were not included in fitACF3.0
  9. Gareth has requested more information from PI groups that have used XCF fitted parameters
  10. Gareth: find out who shall take responsibility for solving the elevation angle fields issue