Status of Delta-DOR interoperability Pasadena Mar 23 th , 2015 - - PowerPoint PPT Presentation
Status of Delta-DOR interoperability Pasadena Mar 23 th , 2015 Mattia Mercolino E SA/ E SOC Summary Study on improved Delta-DOR performance Study on Solar Conjunction impact on Delta-DOR performance Ka-band Quasar catalogue
Pasadena Mar 23th, 2015 Mattia Mercolino E SA/ E SOC
Study on improved Delta-DOR performance Study on Solar Conjunction impact on Delta-DOR
Ka-band Quasar catalogue activties Full Delta-DOR interoperability validation with JPL /
Other activities
A study activity on improved DDOR performance for a 1nrad
accuracy are were kicked-off in August
The study will address the achievable accuracy in all frequency
bands of interest (X/Ka and 25.5-27GHz)
Major error sources for DDOR identified in:
Preliminary Design Review held in February/March
Phase-ripple estimation performed with lab-testing
equipment, i.e. the LDC (420-640 MHz input, 28 MHz output centred at 70MHz)
2 4 6 8
2 4 6 8 10 Frequency relative to 70.2 MHz Second derivative of phase difference (deg/MHz
2)
After preliminary evaluation on possible S/C signal structure that
could accomplish the goal, the choice discussed at PDR has been the following:
as per current standard)
Freqs of X-band sub-carriers as per current RF&Mod spec
Freqs in Ka-band still TBC
like). Codes would be orthogonal for each tone (no interference)
Selectable chip-rate (1.2 – 4.8 Mcps)
Roll-off factor (α) TBC
Code length (L) TBC
Filter length TBC
Example of spectrum with 3.2 Mcps and roll-off of 0.5 Spectrum made of discrete lines as a function of chiprate and code length L
In order to guarantee flexibility the design foresees the possiblity to
select chiprate and mod. index
System can be backward compatible (no code modulation = old
solution with DOR tones)
Two different on-board implementations are under evaluation S/W
simulators for the signal generations and
correlation will be developed
This
will allow to simulate several scenarios, assess the effectiveness of the phase-ripple removal by this modulation scheme and would help finalising the choice of the critical parameters of the code
A study activity in the frame of BepiColombo to evaluate the effect
mission has been started
16 (out of the original 18) VEX DDOR passes were acquired
throughout the whole solar conjunction (-10 deg<SEP<10 deg)
Data processing will start this year (TBC) with the objectives of:
solar plasma at low SEP on DDOR accuracy
DDOR operations in solar conjunction
Activities in MLG
re-installed in MLG in November with successful 24-hours recording
between ESA/NASA/CONAE also agreed for the continuation of the activities until 2022
Chris)
Proposed activities in CEB
PRSR in CEB to allow frame-tie with Robledo.
was done in 2012)
network arrangement (direct VPN connectivity) that we have with the PRSR in MLG
happen before beginning 2016, therefore scan capabilities are limited to 4-5 sources maximum
Preliminary results DOY 187 (1)
Configuration IFMS2: wideband (38 MHz BW) IFMS3 narrowband (19MHz BW)
Preliminary results DOY 187 (2)
a) IFMS 2 data (spanning 38 MHz) correlated in three ways
b) IFMS 3 data (spanning 19 MHz) correlated with the standard NB algorithm to check internal data consistency
The clock model is not uniformly removed from the residuals. Once this is done, results of NB correlation get consistent with the
residuals lining up on the uncompesated dynamics, as shown in the following plot.
The residuals in WB (red points in the plot) do not fit as good (not
implemented the modification allowing for the single estimation of the clock model (it will be done in the near future))
Preliminary results DOY 187 (3)
After consistent removal of the clock offset (common clock offset on all scans) in NB
Preliminary results DOY 208
Configuration IFMS2: wideband (57 MHz BW) IFMS3 wideband(38MHz BW)
Summary
Results look quite consistent and in line with the expected
accuracies.
These data were also extremely useful for ESA to spot some little
inconsistencies in our processing and will make us able to freeze the station configuration to be used for the MRO tests later this year and finally for InSight.
DSN data of DOY 215 for mixed baseline validation needed Complete delivery of ESA data to JPL for finalisation of data
processing (data delivered at the meeting)
Need for OD validation (ESA can perform a pass-through – TBC
but OD validation shall be under JPL responsibility)
More passes to come in 2015 on MRO
Validation with JAXA: acquisition on Hayabusa-2 has been supported in December
1)
Data of DOY 363 provided to JAXA (during the meeting) for further processing
2)
Usuda station data needed to complete validation Validation with BITTT
1)
Chang’E-3 moon landing supported by NNO.
2)
Further DDOR scans taken after landing. Data translated to RDEF and provided to the Chinese. No raw data received from the Chinese. No results of DDOR scans from ESA baseline received from the Chinese.
3)
Further tests with GAIA planned in 2015 Validation with FSA – TBD
New modem generation (TTCP), replacing the IFMS is being
developed.
functions, an open loop receiver with the following characteristics:
Output BW (spec 160 MHz) IF: L-band (420-640 MHz) Channels: up to 8 Sample rate/size: from 1kHz to 16 MHz in 1kHz steps, 1 to 16
bits quantisation (16 MHz is with 2 bit max)
Format: RDEF
Deployment of Microwave radiometers at ESA DS sites
Cebreros in November 2014
Main purpose: to collect attenuation statistics at X/Ka band Can also be used to provide good estimations of tropospheric
wet path delay
This functionality will be tested before summer, and could be
applied to have better tropocals
(current timeframe for installation: beginning 2016)
priority since no Ka-band capability present in NNO)