TAIGA-HiSCORE detection of the CATS-LIDAR on the ISS as fast moving - PowerPoint PPT Presentation

TAIGA-HiSCORE detection of the CATS-LIDAR on the ISS as fast moving point source A.Porelli, R. Wischnewski (DESY) for the TAIGA-Collaboration ICRC2017, Busan, 13.7.2017 R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

Outline - The Timing Array HiSCORE - ISS-LIDAR ground detection - main mode: unscattered light front - also: strong forward scattering in clouds - Absolute pointing calibration by combined HiSCORE + MASTER observation - HiSCORE - CATS analysis - ISS-LIDAR is a unique tool: calibration / verification - Summary R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

The TAIGA-Collaboration Skobeltsyn Institute of Nuclear Physics MSU, Moscow, Russia Institute of Applied Physics, ISU, Irkutsk, Russia Institute for Nuclear Research of RAN, Moscow, Russia Dipartimento di Fisica Generale Universiteta di Torino and INFN, Torino, Italy Max-Planck-Institute for Physics, Munich, Germany Institut für Experimentalphysik, University of Hamburg, Germany IZMIRAN, Moscow Region, Russia DESY, Zeuthen, Germany National Research Nuclear University MEPhI, Moscow, Russia JINR, Dubna, Russia Novosibirsk State University, NSU, Novosibirsk, Russia Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia ISS, Bucharest, Romania and Sternberg Astronomical Institute, MSU, Moscow, Russia (MASTER optical telescope, this work) For CATS/LIDAR: discussion and cooperation with NASA team are acknowledged. Further TAIGA papers @ICRC2017: ● TAIGA-HiSCORE Status (I.Yashin) ● Search for HE-Crab signal (L.Sveshnikova) ● TAIGA Status (N.Bundev) ● TAIGA-IACT (3 x Poster) R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE : a wide angle Timing Array for Astronomy  Air-Cherenkov Array of optical stations, to measure light arrival times & intensity in clear, moonless nights. 1 km Stations: distributed on o(km2)  Reconstruct: shower direction, core location (+ E)  Expect: ● PSF of ~0.1deg at E>100 TeV ● Absolute pointing of <0.1deg needed.  Need an independent pointing check: - Moon/Sun unusable (cf. Argo, NuTel) , - Crab-Nebula as “standard candle” doesn't give strong signal yet. A.Porelli , R.Wischnewski, A.Garmash, AG | CTAS/ISS detection – a unique tool for HiSCORE | 2070608 | Page Curved shower front (“cone”)

HiSCORE observation of the CTAS-LIDAR onboard ISS  Serendipitous discovery:  High counting rate intervals, with 4 kHz  Close to Zenith passage  Prefect plane-wave reconstruction instead of curved EAS profile ISS track on local sky (line), and reconstructed HiSCORE events Counting rate bursts; 4kHz signal R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE’s first source: ISS - Laser flashes with 10ns 1mJ Adapted from CATS First shown in fall 2016 • Excellent HiSCORE calibration source - flat timing profile - precision pointing • Further Interest : - useful for IACTs (HESS, MAGIC, CTA…) ? A.Porelli , R.Wischnewski, A.Garmash, AG | CTAS/ISS detection – a unique tool for HiSCORE | 2070608 | Page - LIDAR physics: opens forward scattering

The ISS/CATS LIDAR observation For details, see NASA website https://cats.gsfc.nasa.gov R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

LIDAR beam into Clouds: Forward scattering observed A different class of events: non strictly plane waves. ● We detect a fast moving beam spot (the primary beam hits a few-km-away dense cloud) --> ISS (8 km/s at 410 km) --> HiSCORE few km Cloud is scattering Target --> fast moving ‘point’ R. Wischnewski | HiSCORE detetction of LIDAR on-board the ISS | 13.7.2017 | Page

Cloud events: HiSCORE sees forward scattering  Right: Phase analysis wrt. 4 kHz - Delay by additional path length from forward scattering  Left: Reconstruction of cloud height from scattered ISS-beam (preliminary) R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE / MASTER combined analysis: Golden Event Method:  We analyze the bright spot of the MASTER image and the HiSCORE events with highest Max-amplitude detected  To compare the MASTER detection with HiSCORE reconstructed direction we need to correct for the parallax effect due to the close distance of the ISS (~400km) and the distance between MASTER and HiSCORE (~500m) (backup slides for more details)  Result: HiSCORE miss pointing error estimation = (0.066+-0.005)° R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

Combined HiSCORE and MASTER/optical observation  MASTER Telescope at Tunka-site: Robotic telescopes for sky-scan (LIGO / Antares/ Ice3) VWF and Master-II  Record “Golden ISS Event” on 20170325: - Unambiguous sky-localization of ISS track + Maximum of Emission by Optical Tel - R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

Combined HiSCORE and MASTER/optical observation  MASTER Telescope at Tunka-site: Robotic telescope net sky-scan (LIGO / Antares/ Ice3) VWF and Master-II  Record “Golden ISS Event” on 20170325: This is a breakthrough: (1) Confirmation that HiS points correctly ! (2) Light seen directly from ISS R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE / CATS combined analysis  The HiSCORE data is analyzed together with the CATS data to obtain a complete description of the detection process  10 passages analyzed in total:  4 from 2015/16 (+ 20160208: w/o CATS data)  6 from 2016/17  Analysis performed for each detected passage, using the following data:  HiSCORE data  CATS data  NORAD TLE for ISS (with SGP4 software)  Analysis main steps:  CATS/TLE data time correction (DT-CATS)  HiSCORE / TLE data time alignment  The different steps of the analysis correct for some uncertainties in CATS and in TLE prediction. R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE/CATS combined analysis  Two time-corrections are needed: 1. CATS 1-2 sec different from TLE-prediction, CATS-update is likely 2. TLE-prediction needs a 0.0 - 0.7 sec shift → limited TLE precision (time + location ;work in progress) ● Zenith vs. time (left): TLE, CATS (corr / uncorr) + HiSCORE (blue) ● Beam-spot distance vs time (black), HiSCORE maxAmpl (blue) R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

HiSCORE/CATS combined analysis  The HiSCORE/CATS combined analysis puts together all the HiSCORE and CATS data, using the TLE prediction as reference  We obtain a coherent description of the detection  It is possible to extract the ‘passage parameters’ from the different data sets (see table in the backup slides)  Summary of 2015-2017 detections Amp(max) vs. Spot distance R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

ISS/CATS LIDAR: Applications for HiSCORE  Allows for an independent check of calibration methods used so far Amp(max) vs. Spot distance - 1 passage - all passages R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

ISS/CATS LIDAR: calibration of HiSCORE  Calibrate time-offsets between stations ● Left: distribution of t_off for different methods (pusre LED, EAS-LEDs, ISS)  Looking at the fit residual distribution (right) R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

ISS/CATS LIDAR: HiSCORE pointing verification  A method to measure the angular resolution (PSF)  Angular spread between neighbouring laser events: ● from identical position: 0.25ms (4kHz) → 2 m motion at 400 km ● Find ~0.14 deg (prelim., work in progress) for plane-wave events R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

Summary (1)  ISS-CATS/LIDAR events are a unique calibration tool for HiSCOR ● 11 passages from 2015-2017 , part of observation program.  Main light component: direct, unscattered light from tail of beam; observed at few km-distance from ground spot; <1 ns jitter, compatible with our resolution  Main result: -- HiSCORE is operating as a precision instrument. with absolute astronomic pointing is proven to <0.1 deg precision – essential input for point source search; see next talk: search for gammas from Crab-Nebula  Breakthrough: combined HiSCORE and Master/optical observation (“Golden event”)  Open: need high precision tracking of ISS (TLE) and possible update (improved precision) of CATS pointing data. Progress expected soon. R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

Summary (2)  Beyond absolute pointing calibration calibration: ISS is a “test beam” to  calibrate HiSCORE time offsets  check amplitudes calibration / verification amplitude (relative/absolute)  measure and monitor station time resolution  data-quality control  Plane-Wave ISS events allow for performance and quality checks of hardware, data-processing and reconstruction. (EAS-events are statistics dominated; unlike the laser-beam)  Forward scattering in clouds observed: ground detection might complement LIDAR data, by simultaneous forward measurement.  Other Air-Cherenkov projects (+ fluorescence?) can probably use the ISS-LIDAR . R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |

 Thanks. Backup R. Wischnewski | HiSCORE Detection of ISS-LIDAR | 13.07.2017 |