Delta-DOR Working Group Meeting Summary Oct 26-30, 2020
Achievements from the meeting cycle include progress with higher resolution PN DOR signals, resolution of RIDs, and completion of the final draft of the architecture Magenta Book. Updates to OPS MB-3 and RDEF BB-2 were discussed, along with results from new interoperability tests. Future considerations focus on maintaining compatibility for RDEF and updating DDOR OPS MB.
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Delta-DOR WG Minutes of the Meeting WebEx Only October 26-30, 2020 James Border, NASA/JPL James.S.Border@jpl.nasa.gov
List of participants James Border, NASA/JPL, Chair (JB) Javier de Vicente, ESA/ESOC, Deputy Chair (JdV) Chris Volk, NASA/JPL, Member (CV) Marco Menapace, ESA/ESOC, Member (MM)
Agenda Introduction, Review of Agenda Report on Cross-Support Activity at each Agency Review of draft Architecture MB Review of C. Volk proposed updates to Observation File and Support Request for PN DOR Report on ESA/NASA interoperability tests using POLR/TTCP (MM and CV) Discussion of material to include in OPS MB-3 regarding integer downconverter convention Discussion of material to add to BB-2 (RDEF) including DOR multiplier as floating point Review of Action Items Any Other Business Plan to hold WebEx about once a month to update status on work assignments
Achievements for this meeting cycle Agency Review completed on REC 2.5.7B for new, higher resolution, PN DOR signals, to be included in 401-B RIDs have been resolved Both NASA and ESA agreed to provide prototype test results in Yellow Books Expect to resolve for publication next Spring Final draft of architecture Magenta Book was completed Some editorial work remains In progress updates to OPS MB-3 and RDEF BB-2 were reviewed Reviewed results from new interoperability tests with BepiColombo DDOR passes using existing D-DOR signals and two new Open Loop Receivers: NASA OLR and ESA TTCP Data agreement is good, but minor differences are seen and more study is recommended Conventions for DDOR using new receivers to be documented in OPS MB-3 Preliminary database of quasar flux was reviewed Looks very promising for improving planning for DDOR passes Interaction with other WGs Joint activity with RF&Mod to continue next meeting Joint activity with CSSM is expected next meeting Joint activity with NAV is expected next meeting
Future Considerations BB should remain backwards compatible if possible (for RDEF) Add draft project for update to DDOR OPS MB -- Done Include exchange of quasar SNR PN DOR will require enough changes that OBS (in BB) and Support Request (in MB) will likely not be backwards compatible These items only affect DDOR What changes might be needed if RDEF files are used for TLM arraying? Should this be standardized (maybe new MB)? Should antenna characteristics be provided in standard form to enable scheduling of VLBI Should antenna pointing predictions for VLBI-like passes be standardized Architecture MB Include material on high performance short arc tracking using 3+ stations Concurrent DOR and TLM (impacts choice of mod index) May be more useful for CubeSats Interoperability tests for VLBI and/or DDOR with radiometers at each site
Action Item Results 18 Action Items were discussed 5 of these were closed 4 new Action Items were assigned Action Item list updated in Meeting Folder in CWE
Mid/Long Term Schedule Date Milestone Final draft completed of DDOR architecture Magenta Book Further discussion of updates to RDEF BB and DDOR OPS MB Work with RF&Mod to Resolve RIDs in 401.0-B, 2.5.7B Continue discussion of interoperability tests Continue interaction with CSS-SM and Navigation WGs Fall 2020 Review drafts of RDEF BB and DDOR OPS MB Resolve for DDOR Architecture Magenta Book to be published Review quasar SNR data base Review proposed updates to TDM Continue discussion of interoperability tests Continue interaction with CSS-SM/RF&Mod/Navigation WGs Spring 2021 Further review of drafts of RDEF BB and DDOR OPS MB Resolve RIDs for DDOR Architecture Magenta Book Continue discussion of interoperability tests Continue interaction with CSS-SM/RF&Mod/Navigation WGs Fall 2021
Actions statistics (not updated) Total actions: Open actions: Actions closed by 2016-Spring Actions taken at the 2016-Spring Actions closed by 2016-Fall Actions taken at the 2016-Fall Actions closed by 2017-Spring Actions taken at the 2017-Spring Actions closed by 2017-Fall Actions taken at the 2017-Fall Actions closed by 2018-Fall Actions taken at the 2018-Fall Actions closed by 2019-Spring Actions taken at the 2019-Spring Actions closed by 2019-Fall Actions taken at the 2019-Fall 208 26 (15) (160) (10) (166) (9) (171) (4) (186) (14) (187) (12) (189) (8) (208) 6 4 9 6 7 5 11 15 5 1 4 2 5 19
DDOR WG BOOK STATUS DDOR WG BOOK STATUS
Books updates [1] Green Book Issue 3 New ideas discussed for Issue 3 (few years off) JAXA to add description of Sweeping DOR Tone Update to PN DOR section in GB-2 using lessons learned Improve estimate of Phase Dispersion Addition of existing systems (last section) for other Agencies Importance of improved tropospheric calibration for high accuracy DDOR Dual band X/Ka DDOR for low Sun angle tracking Re-examine error estimates Add material as needed to support DDOR Architecture MB Typos in GB2 Section 5.3 first paragraph and third paragraph: change 5.1.3 to 5.1.4
Book updates [2] RDEF BB revision Representation of Downlink conversion chain (to be discussed in the frame of BB update) JPL proposed the adoption of an improved signal phase representation Separate integer part and fraction part so that enough digits are available to fully represent down-conversion frequency and phase, which shall be studied and traded off with respect to current method in use ESA proposed the adoption of a different method to represent Doppler compensation (TBC), which shall be further addressed and discussed among the WG members Issue whether integer downconversion is achievable in all HW implementations (current and future) If this is not the case, check RDEF representation of fractional frequencies First data sample should have a small (e.g. few ns) fixed offset wrt the nominal integer second. The new BB version shall include this as a requirement.
Book updates [3] RDEF BB revision - continued Consider the use of RDEF for other types of application (e.g. radio- science, open loop recording for TM playback, etc.) (For many uses): Inclusion of AGC information in the dataset (will be Agency dependent) Information on polarisation (OK, add to header) (For radio-science): U/L frequency (station frequency plan) information and information on ramping (or equivalent representation) (should be reported in TDM) (For TM demodulation): Expected mod. Index, expected Es/N0, symbol-rate, etc. (not part of open loop recording) Phase offset information between channels (or document how this can be treated in the current definition of RDEF) Editorial: update definition of sample resolution (use number of bits per sample instead of sample resolution) Editorial: Review the explanation in the following: Truncation shall be used, to reduce the number of bits per sample to the desired value. NOTE - This truncation creates an offset of -0.5 in the output data stream values that needs to be corrected in post processing software
Book updates [4] RDEF BB revision - continued Editorial: Review the whole parameter description in the book to make it less ambiguous On page 5-12, consider the parameter CHN_ACCUM_PHASE to be integer part of a downconverter phase at the beginning of the second and the CHN_PHASE_POL_COEFF0 to be the fractional part of the same phase at the beginning of the second Addition of dedicated Header record to specify header record length (to be added?) Use spare field? Conform to CCSDS SFDU specification? Discuss with each agency any possible/desired changes to RDEF header information Update OBSERVATION File to allow DOR multiplier to be a real number instead of ratio of integers Update OBSERVATION File to include reporting of PN spacecraft signals
Book updates [5] MB on DDOR architectures Revised draft of book was produced by ESA and presented Fall 2020 Draft was reviewed and an updated near-final draft was completed Need to determine if ICS PROFORMA is required Need to determine if Prototype is required Editorial work to continue Expect to resolve for publication at next Spring meeting
Book updates [6] Issue 3 of DDOR OPS MB Project is approved in Framework in CWE C. Volk to be editor This version adds support for PN DOR Add a Note that integer downconversion is preferred for DDOR when using fixed frequency downconversion Loss of accuracy may result if fractional downconversion is used Must resolve issues with Registries It must be possible to create a valid Support Request by referencing Registries as indicated in MB This version uses XML format for the two products that make up the Support Request CSSM is expected to reference this book and the XML Support Request products as it defines Service for inter-agency DDOR
Interactions with other WG [1] RF&Mod All RIDs resolved on new Recommendation 2.5.7B on PN DOR, to add to 401.0-B NASA and ESA must each produce Yellow Book with prototype test results RF&Mod has requested this be done by next meeting RF&Mod will resolve for publication when YB are ready, maybe at next Spring meeting CSSM DDOR is waiting for CSSM to decide how the DDOR Support Request products in MB-3 will fit into the framework of Service Management NAV DDOR is suggesting TDM updates Need to present proposal to NAV WG
