Trabajo presentado al LiteBIRD Global Face to Face Meeting, celebrado en Sagamihara (Japón) del 3 al 5 de julio de 2019

Barreiro, R. Belén

Bermejo-Ballesteros, J.

Casas-Reinares, F. J.

Cubas, Javier

García-González, Judit

Martínez-González, Enrique

Sanz-Andres, A.

Vielva, P.

English

Vielva, Patricio

Digital.CSIC

SPAINFeasibility Study for a Calibration Satellite To expand beyond LiteBIRD full success scientific goalsPayload: Calibration SourceCal. source diagram Frontal view sketch- Multi-frequency (6-bands) variable source covering 34 - 450 GHz- Signal frequency and power should be variable for systematics characterization- CW amplitude- and frequency-variable signals and also broadband signals- Common low-frequency sources to feed the different bands: CW frequency-variable (bandwidth BWLF) and broadband noise source (NS)- A variable attenuator (VA) change the power level in linearity calibrations. VA applied directly to the common low- frequency signals to reduce the cost and complexity.  - Bandwidth coverage achieved by means of power splitters and Frequency Multipliers (FM)- Band-Pass Filter (BPF) rejects undesired harmonics and Directional Coupler (DC) measure power levels with a Zero-Bias-Detector (ZBD).- Feed-horns: circular at lowest frequencies (lower gain and size) and rectangular at highest freq. (higher gain required)- Cross-polarization of -60 dB: Wire-Grid Polariser in front of the horns (precise alignment with the polarization axis)- Alternative source designs and technologies (thermal source, microwave photonic source…) are being also considered     Estimated Characteristics:- Volume: 10 cm x 10 cm x 20 cm- Weight: 1.3 kg - Power consumption: 50 W Wave-guide FlangeConcurrent Design AnalysisMissionLCS has been pre-designed in IDR-UPM’s Concurrent Design Facility (CDF)It has been designed as a piggy-back of the LB minimizing the impact on its architecture. The concept of LCS can be extended to a microsatellite capable of reaching L2 autonomously by modifying mainly the propulsion and communication subsystems.Main Specifications:       - 3 years mission      - Size: 6U Cubesat.      - Minimum distance between LCS and LB of 240 m;       - Calibration distance = 270 ± 3 m;       - Distance error determination < 13.5 cm;       - LB direction location error < 10’; LB orientation detection error < 1’;       - LCS pointing error < 3’;       - Power enough for 1 calibration per month;       - Minimum impact on LB (CubeSat deployer and 3 patch antennas).Critical Technologies:      - Attitude control and determination: Sun sensors (Fine Sun Sensor)           and star trackers (CubeSpace CubeStar).      - Metrology (relative position determination) and communications: RF         ranging e.g. “Swift RelNav” by Tethers Unlimited.      - Propulsion: Cold gas thrusters (small and precise impulses with low         consumption) e.g. GOMSPACE NanoProp.Thermal Control:       - A preliminary LCS design implemented in the ESATAN® software           shows a maximum temperature of 39 ºC in the solar panels.       - In the covered bandwidth by the telescope, this corresponds to a         noise signal of 70 fW/pixel that is ten times below the LCS calibration         signal at those frequencies.Overall features:       - Total mass: 7.07 kg (dry mass) + 0.08 kg (propellant).      - Power: 2 orientable arrays of 6U-cubesat solar panels with a triple-        junction technology by SpectroLabs.      - Total power generation: 57.2 W.Calibration strategy analysisLCS must be inside LB’s FoV during calibration and move away at finishing.    – 4 impulses for each calibration manoeuvre.LiteBird scanning law and LCS relative position define:    – Total access time.    – Number of viewed LB instrument sensors.The best option to place the LCS is close to the anti-Sun axis.    – The percentage of viewed sensors is around 14% but it reaches the 70% in that region for one day even when the LCS is at the same position.   – Average access time is uniform and around 30 s,       regardless of the LCS position.LCS MissionLissajous orbit like Planck and Herschel.Formation flying of LCS and LB for periodic calibration.Orbit maintenance:   –  Manoeuvres required periodically.  –  L2 presents low force gradients.  –  Very low ΔV (∼1 m/s per year).Control strategy, formation, orbit and tolerance define a calibration: ΔV of 9 m/s for the entire mission.Exterior view and exploded view of LCS.CalibrationTotal access time according to the position of LCS relative to LB throughout 90 minutes.Contribution  to Calibration, Systematics and Foregrounds JSGs Interest in Data ManagementExpertise and other potential contributions- Polarization angle requirements on each frequency induced by the component separation process:Estimated CMB (both, Q and U Stoke’s parameters) at position pData at frequency ν and position pWeight given at each frequency ν (pixel independent)error in 𝛅(r) as a function of the correlation degreeν(GHz)α [arcmin]2  parameter(from Yuto)40  59.275050 17.643060 8.152068 3.450078 2.161089 1.5396100 1.2960119 1.0160140 1.2010166 1.8050195 2.6320235 6.0550280 11.9040337 53.3570402 360.1110δr (% sys. ) 1.612• In order to assure a 1% of the budget assigned to systematics, the requirements are not far from the expected errors coming from EB = 0 at the spectra level.• If correlations among frequencies are below 60%, even the most damaging case (in the sense of polarization angle error) is below the budget.Expertise• IFCA was the Spanish DPC node for Planck-LFI• The IFCA Advanced Computing and e-Science group will support the DPC management:• Foster the usage, maintain and improve the existing computing and storage infrastructures • Expertise in building software quality assurance systems• Implement industry-standard best practices• Continuous build, integration and deployment of scientific software• Containerization (Docker) of software components to ease sharing, deployment and distributionHardware resources at IFCA• Altamira supercomputer (RES)- 158 nodes 32 cores, 64GB RAM, Infiniband connection + 4 GPU nodes- 7.4M CPU hours since May 2018• Grid resources - 4M (56M normalized) CPU hours in 2018• OpenStack Cloud: http://portal.cloud.ifca.es/- Up to 7700 cores availableLargest node: 48 cores, ~1TB RAMGPU nodes: 1 NVIDIA TitanX (donated by NVIDIA grant), 1 NVIDIA 1080ti, 10 NVIDIA 1080ti90 nodes with In niband connection1st overall resource provider (size) in EGI.eu Federated Cloud- 1st overall contributor (CPU-hours) in EGI.eu Federated Cloud6M CPU hours during 2018• Renewed storage system (2018)- Cloud: Up to 300TB (Ceph) via object storage (S3-like) or block storage- GPFS: 1PB GPFS storage + 1PB tapeInterest in DPC activitiesThe funding expected from the National Research Program for Space and IFCA, in relation to the DPC, can be used for:• Computing (~ 500 cores)• Storage (0.5 PB)• 2 FTE• Design, development and characterization for CMB Instrumentation:• Planck-LFI for 30GHz and 44GHz• QUJOTE TFI and FGI• Optical Interferometric prototype for microwave signals• Calibration sources for CMB polarization• Computation• high-performance, grid and cloud computing• Development of support chains for data management• Component separation• Diffuse component extraction• Compact source detection and estimation• Optimal power spectra estimation• CMB cross-correlations: secondary anisotropies science• Isotropy and Statistics on the universe: inflation paradigm, non-Gaussianity, anomalies, topological defects• Development, fabrication, integration and operation of CMB experiments over more than 30 years (some of them in-house, others in collaboration with other institutes)• Most recent ones: COSMOSOMAS (10-17 GHz, 1998-2008), VSA (33 GHz, 1999-2008), and QUIJOTE (10-40 GHz, 2012-)• Future experiments: GroundBIRD (150-220 GHz), LSPE- STRIP (43, 90 GHz), TMS (10-20 GHz)• Programming and planning observational programs• Basic data processing and data reduction (calibration, characterization of noise properties, characterization of systematics, data flagging).• Characterization of foregrounds (mainly at low frequencies, synchrotron and AME) both in intensity and in polarisation, and component separation• Extraction of power spectra and cosmological-parameter estimation• Statistical tools and techniques: MCMC, cross-correlations.Planned extension to the Southern hemisphere to cover the full skyCurrent and future QUIJOTE maps will be essential to clean higher-frequency maps (including LiteBIRD) from synchrotron emission:• Synchrotron contributes to r=0.01 @ 200GHz in 70% of sky (Planck 2015 results X)• Preliminary QUIJOTE results 🡺 <βs>P = -3.00 ± 0.05, with dust-sych ρ ~0.20 ± 0.06, with high variability in the sky- Expected contribution to the component separation process using Internal Template Fitting and Neural NetworksSC National member: Enrique Martínez-González martinez@ifca.unican.es

To expand beyond LiteBIRD full success scientific goals

https://digital.csic.es/bitstream/10261/214465/1/feasibilisatelli.pdf

To expand beyond LiteBIRD full success scientific goals

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