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The astrophysical complex TAIGA (Tunka Advanced Instrument for cosmic-ray physics and Gamma-ray Astronomy), whose first phase is being completed in the Tunka valley 50 km from Lake Baikal, is described. Its research program, first results, and development prospects are discussed.

37th International Cosmic Ray Conference, ICRC 2021, Berlin, online, Germany, 12 Jul 2021 - 23 Jul 2021; Proceedings of Science / International School for Advanced Studies (ICRC2021), 273 (2021). doi:10.22323/1.395.0273, Air-shower radio arrays operate in low signal-to-noise ratio conditions, which complicates the autonomous measurement of air-shower signals without using an external trigger from optical or scintillator detectors. A simple threshold trigger for radio detector can be efficiently applied onlyin radio-quiet conditions, because for other cases this trigger detects a high fraction of noise pulses. In the present work, we study aspects of independent air-shower detection by dense antenna clusters with a complex real-time trigger system. For choosing the optimal procedures for the real-time analysis, we study the dependence between trigger efficiency, count rate, detector hardware and geometry. For this study, we develop a framework for testing various methods of signal detection and noise filtration for arrays with various specifications and the hardware implementation of these methods based on field programmable gate arrays. The framework provides flexible settings for the management of station-level and cluster-level steps of detecting the signal, optimized for the hardware implementation for real-time processing. It includes data-processing tools for the initialconfiguration and tests on pre-recorded data, tools for configuring the trigger architecture andtools for preliminary estimates of the trigger efficiency at given thresholds of cosmic-ray energyand air-shower pulse amplitude. We show examples of the trigger pipeline developed with this framework and discuss the results of tests on simulated data., Published by SISSA, Trieste

The relevance and benefits of the new TAIGA gamma observatory complex in the Tunka Valley (50 km from Lake Baikal) are discussed. The main aim of the TAIGA installation is to study high-energy gamma radiation and search for cosmic pevatrons. The first series of gamma stations was commissioned in 2019 and covers an area of 1 km2. Its expected integral gamma radiation sensitivity at an energy of 100 TeV over 300 h of source monitoring is (2–5) × 10−13 TeV cm−2 s−1. It is planned to expand the effective area of TAIGA gamma observation to 10 km2 in the future.

The Tunka-133 Cherenkov complex for recording extensive air showers (EAS) collected data over seven winters from 2009 to 2017. The differential energy spectra of all particles was acquired in the 6 × 1015–3 × 1018 eV range of energies over 2175 h. The TAIGA-HiSCORE complex is continually being expanded and upgraded. Data acquired by 30 first-line stations over 35 days during the period 2017–2018 is analyzed in this work. As at the Tunka-133 setup, the primary particle energies above 1015 eV are measured using the density of the Cherenkov light flux at a distance of 200 m from a shower’s axis. Data on lower energies are collected by determining the energy of the light flux near a shower’s axis. This results in a spectrum of 2 × 1014–1017 eV. The combined spectrum for the two systems covers a range of 2 × 1014–2 × 1018 eV.

The study of the ultra-high energy cosmic rays, neutrinos and gamma rays is one of the most important challenges in astrophysics. The low fluxes of these particles do not allow one to detect them directly. The detection is performed by the measuring of the air-showers produced by the primary particles in the Earth's atmosphere. A radio detection of ultra-high energy air-showers is a cost-effective technique that provides a precise reconstruction of the parameters of primary particle and almost full duty cycle in comparison with other methods. The main challenge of the modern radio detectors is the development of efficient self-trigger technology, resistant to high-level background and radio frequency interference. Most of the modern radio detectors receive trigger generated by either particle or optical detectors. The development of the self trigger for the radio detector will significantly simplify the operation of existing instruments and allow one to access the main advantages of the radio method as well as open the way to the construction of the next generation of large-scale radio detectors. In the present work we discuss our progress in the solution of this problem, particularly the classification of broadband pulses., Comment: 6 pages, 1 figure

One of the most informative methods of cosmic ray studies is the detection of Cherenkov light from extensive air showers (EAS). The primary energy reconstruction is possible by using the Earth’s atmosphere as a huge calorimeter . The EAS Cherenkov light array Tunka-133, with ∼ 3 km 2 geometrical area, is taking data since 2009. Tunka-133 is located in the Tunka Astrophysical Center at ∼ 50 km west of Lake Baikal. This array allows us to perform a detailed study of the energy spectrum and the mass composition in the energy range from 6 ⋅ 1 0 15 eV to 1 0 18 eV . Most of the ongoing efforts are focused on the construction of the first stage of the detector TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy). The latter is designed for the study of gamma rays and charged cosmic rays in the energy range of 1 0 13 eV – 1 0 18 eV . The TAIGA prototype will consist of ∼ 100 wide angle timing Cherenkov stations (TAIGA-HiSCORE) and three IACTs deployed over an area of ∼ 1 km 2 . The installation of the array is planned to be finished in 2019 while the data-taking can start already during the commissioning phase. The joint reconstruction of energy, direction, and core position of the imaging and non-imaging detectors will allow us to increase the distance between the IACTs up to 800 m, therefore providing a low-cost, highly sensitive detector. The relatively low cost together with the high sensitivity for energies ≥ 30–50 TeV make this pioneering technique very attractive for exploring galactic PeVatrons and cosmic rays. In addition to the Cherenkov light detectors we intend to deploy surface and underground muon detectors over an area of 1 km 2 with a total area of about 1000 m 2 . The results of the first season of coincident operation of the first ∼ 4 m diameter IACT with an aperture of ∼ 10°with 30 stations of TAIGA-HiSCORE will be presented.

The article presents the relevance and advantages of the new gamma observatory TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy), which is being constructed in the Tunka Valley 50 km from Lake Baikal. Various detectors of the six TAIGA gamma observatory arrays register the Cherenkov and radio radiation, as well as the electron and muon components of EAS. The primary objective of the TAIGA gamma observatory is to study the high-energy part of the gamma-ray spectrum, in particular, in order to search for Galactic PeVatrons. The energy, direction, and position of the EAS axis are reconstructed in the observatory based on the data of the wide-angle Cherenkov detectors of the TAIGA-HiSCORE experiment. Taking into account this information, the gamma quanta are distinguished from the hadron background using the data obtained by the muon detectors and telescopes that register the EAS image in the Cherenkov light. In this hybrid mode of operation, the atmospheric Cherenkov telescopes can operate in the mono-mode, and the distance between them can be increased to 800–1000 m, which makes it possible to construct an array with an area of 5 km2 and more at relatively low cost and in a short time. By 2019, the first stage of the gamma observatory with an area of 1 km2 will be constructed; its expected integral sensitivity for detecting the gamma radiation with an energy of 100 TeV at observation of the source for 300 hours will be approximately $$2 \times 5$$ 10–13 TeV cm–2s–1.

The Tunka-Grande array is part of an experimental complex located in the Tunka Valley (Republic of Buryatia, Russia) about 50 km from Lake Baikal. This complex also contains the Tunka-133 and Tunka-Rex arrays. The aim of this complex is to study the primary cosmic ray energy spectrum and mass composition in the energy range of 1016–1018 eV, and to search for diffuse gamma rays in the energy range of 5 × 1016–5 × 1017 eV. The design of the Tunka-Grande array and the procedure for reconstructing the parameters of extensive air showers (EASes) are described, and preliminary results are presented from the search for diffuse gamma rays with energies of more than 5 × 1016 eV.

The Tunka Radio Extension (Tunka-Rex) is a digital antenna array for the detection of radio emission from cosmic-ray air showers in the frequency band of 30 to 80 MHz and for primary energies above 100 PeV. The standard analysis of Tunka-Rex includes events with zenith angle of up to 50$^\circ$. This cut is determined by the efficiency of the external trigger. However, due to the air-shower footprint increasing with zenith angle and due to the more efficient generation of radio emission (the magnetic field in the Tunka valley is almost vertical), there are a number of ultra-high-energy inclined events detected by Tunka-Rex. In this work we present a first analysis of a subset of inclined events detected by Tunka-Rex. We estimate the energies of the selected events and test the efficiency of Tunka-Rex antennas for detection of inclined air showers., ARENA2018 proceedings

The Tunka Radio Extension (Tunka-Rex) is a digital radio array operating in the frequency band of 30-80 MHz and detecting radio emission from air-showers produced by cosmic rays with energies above 100 PeV. The experiment is installed at the site of the TAIGA (Tunka Advanced Instrument for cosmic rays and Gamma Astronomy) observatory and performs joint measurements with the co-located particle and air-Cherenkov detectors in passive mode receiving a trigger from the latter. Tunka-Rex collects data since 2012, and during the last five years went through several upgrades. As a result the density of the antenna field was increased by three times since its commission. In this contribution we present the latest results of Tunka-Rex experiment, particularly an updated analysis and efficiency study, which have been applied to the measurement of the mean shower maximum as a function of energy for cosmic rays of energies up to EeV. The future plans are also discussed: investigations towards an energy spectrum of cosmic rays with Tunka-Rex and their mass composition using a combination of Tunka-Rex data with muon measurements by the particle detector Tunka-Grande., Comment: ARENA2018 proceedings

The Tunka-Grande scintillation array is described. The first results from its operation are presented. The prospects for studying primary cosmic rays in the energy range of 1016 to 1018 eV during simultaneous registration of the Cherenkov and charged particle components along with radio emissions from extensive air showers are discussed.

The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, cosmic ray physics from 100 TeV to several EeV as well as for search for axion-like particles, Lorentz violations and another evidence of New Physics. In 2020 year a one square kilometer TAIGA setup should be put in operation.

The combination of a wide angle timing Cherenkov array and Imaging Atmospheric Cherenkov Telescopes operated in mono mode offers a cost-effective way to construct a few square kilometers array for ultrahigh-energy gamma astronomy. The first stage of the TAIGA Observatory (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is described here. It will comprise TAIGA-HiSCORE - 120 wide angle Cherenkov stations distributed over an area of 1.0 km2 and three IACTs (TAIGA-IACT).

The physics motivations and advantages of the new TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) detector are presented. TAIGA aims at gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV. For the energy range 30 – 200 TeV the sensitivity of 10 km2 area TAIGA array for the detection of local sources is expected to be 5 × 10-14 erg cm-2 sec-1 for 300 h of observations. Reconstruction of the given EAS energy, incoming direction and its core position, based on the timing TAIGA-HiSCORE data, allows one to increase a distance between the IACTs up to 600-1000 m. The low investments together with the high sensitivity for energies ≥ 30-50 TeV make this pioneering technique very attractive for exploring the galactic PeVatrons and cosmic rays. At present the TAIGA first stage has been constructed in Tunka valley, 50 km West from the Lake Baikal. The first experimental results of the TAIGA first stage are presented.

In TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma-ray Astronomy) detector we are commissioning the first Imaging Atmospheric Cherenkov Telescope (IACT). The telescope drive system comprises a motor controller and two stepper motors for axis control. For the pointing calibration of the telescope a CCD-camera is installed on the reflector dish of the telescope. The position of the CCD-camera allows us capturing both the Cherenkov camera and the observed source. In this report we describe the telescope positioning and the drive system software as well as the control of the CCD-camera data acquisition, archiving and processing system.

We report the first ground-based observation of the CATS-LIDAR onboard the ISS by the TAIGA-HiSCORE gamma-ray facility, and the MASTER-Tunka Robotic telescope. HiSCORE detects unscattered laser light directly from the ISS, at up to km-scale distance from the laser beam spot on ground. The ISS-LIDAR turns out to be a unique calibration tool, in particular to verify the absolute astronomical pointing of HiSCORE. We detected the LIDAR for 11 ISS-passages; among these were observations of forward scattering of the laser beam in dense clouds, which might carry information complementary to the LIDAR technique. We expect other air Cherenkov installations like IACTs to benefit from this light source.

The physics motivations and characteristics of the new gamma-experiment TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) are presented. The TAIGA experiment addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from $100$ TeV to several EeV. For the energy range $30 - 200$ TeV the sensitivity of the planned for future extension of TAIGA up to $5$ km$^2$ area for detection of the local sources is expected to be $10^{-13}$ erg cm$^{-2}$ sec$^{-1}$ for $500$ h of observation. The combination of the wide angle Cherenkov timing detectors of the TAIGA-HiSCORE array and the $4$ m class Imaging Atmospheric Cherenkov Telescopes of the TAIGA-IACT array with their FoV of $10x10$ degrees offers a cost effective-way to construct a $5$ km$^2$ array. Reconstruction of an EAS energy, direction and core position based on the TAIGA-HiSCORE data will allow us to increase the distance between comparatively expensive IACTs up to $800 - 1200$ m. The low investments together with the high sensitivity for energies $\geqslant 30-50$ TeV make this pioneering technique very attractive for exploring the galactic PeVatrons and cosmic rays. In addition to the Cherenkov light detectors we intend to deploy an array of muon detectors (TAIGA-Muon array) over an area of 1 km$^2$ with a total area of about $2000 - 3000$ m$^2$. The TAIGA-IACT-HiSCORE together with the TAIGA-Muon array will be used for selection of gamma-ray induced EAS. At present the first stage of TAIGA have been constructed in the Tunka valley, $\sim 50$ km West from the Lake Baikal in Siberia. Now it consists of 28 TAIGA-HiSCORE Cherenkov stations distributed over an area of $0.25$ km$^2$ and the first IACT of the TAIGA-IACT array. We are planning to test operation of the single telescope in coincidence with the HiSCORE up to shower impact distances of $\sim 500 - 600$ m; for this purpose we already started construction of the second imaging telescope at $300$ m distance from the first one. During 2017 -- 2019 years we intend to increase the number of the TAIGA-HiSCORE stations up to $100 - 120$, spread on the area of $1$ km$^2$ and to deploy $2$ additional IACTs.

Observations of gamma rays up to several 100 TeV are particularly important to spectrally resolve the cutoff regime of the long-sought Pevatrons, the cosmic-ray PeV accelerators. One component of the TAIGA hybrid detector is the TAIGA-HiSCORE timing array, which currently consists of 28 wide angle (0.6 sr) air Cherenkov timing stations distributed on an area of 0.25 km2 . The HiSCORE concept is based on (non-imaging) air shower front sampling with Cherenkov light. First results are presented.

We present physical motivations and advantages of the new gamma-observatory TAIGA (Tunka Advanced Instrument for cosmic ray physics and gamma-ray astronomy). TAIGA will be located in the Tunka valley, 50 km to the west of Lake Baikal, at the same place as the integrating air Cherenkov detector for cosmic rays Tunka-133. The TAIGA array is a complex, hybrid detector for ground-based gamma-ray astronomy for energies from a few TeV to several PeV as well as for cosmic ray studies from 100 TeV to several EeV. The array will consist of a wide angle Cherenkov array – TAIGA-HiSCORE with 5km2 area, a net of 16 IACT telescopes (with FOV of about 9.72°×9.72°) as well as muon and other detectors. We present the current status of the array construction.

The Tunka Radio Extension (Tunka-Rex) is a digital antenna array, which measures the radio emission of the cosmic-ray air-showers in the frequency band of 30-80 MHz. Tunka-Rex is co-located with TAIGA experiment in Siberia and consists of 63 antennas, 57 of them are in a densely instrumented area of about 1 km\textsuperscript{2}. In the present work we discuss the improvements of the signal reconstruction applied for the Tunka-Rex. At the first stage we implemented matched filtering using averaged signals as template. The simulation study has shown that matched filtering allows one to decrease the threshold of signal detection and increase its purity. However, the maximum performance of matched filtering is achievable only in case of white noise, while in reality the noise is not fully random due to different reasons. To recognize hidden features of the noise and treat them, we decided to use convolutional neural network with autoencoder architecture. Taking the recorded trace as an input, the autoencoder returns denoised trace, i.e. removes all signal-unrelated amplitudes. We present the comparison between standard method of signal reconstruction, matched filtering and autoencoder, and discuss the prospects of application of neural networks for lowering the threshold of digital antenna arrays for cosmic-ray detection., Comment: ARENA2018 proceedings

The Tunka observatory is located close to Lake Baikal in Siberia, Russia. Its main detector, Tunka-133, is an array of photomultipliers measuring Cherenkov light of air showers initiated by cosmic rays in the energy range of approximately 10 16 − 10 18 eV . In the last years, several extensions have been built at the Tunka site, e.g., a scintillator array named Tunka-Grande, a sophisticated air-Cherenkov-detector prototype named HiSCORE, and the radio extension Tunka-Rex. Tunka-Rex started operation in October 2012 and currently features 44 antennas distributed over an area of about 3 km 2 , which measure the radio emission of the same air showers detected by Tunka-133 and Tunka-Grande. Tunka-Rex is a technological demonstrator that the radio technique can provide an economic extension of existing air-shower arrays. The main scientific goal is the cross-calibration with the air-Cherenkov measurements. By this cross-calibration, the precision for the reconstruction of the energy and mass of the primary cosmic-ray particles can be determined. Finally, Tunka-Rex can be used for cosmic-ray physics at energies close to 1 EeV, where the standard Tunka-133 analysis is limited by statistics. In contrast to the air-Cherenkov measurements, radio measurements are not limited to dark, clear nights and can provide an order of magnitude larger exposure.

The problem of chemical composition below the knee in the cosmic-ray energy spectrum has not yet been solved due to low statistics collected from direct experiments. In the HiSCORE experiment the lateral distribution functions (LDF) of Cherenkov light of EASs with energy greater than hundreds of TeV can be measured in detail for millions of individual events. A full steepness of LDF is sensitive to the depth of shower maximum and as a result to primary particle type. In this paper, we developed a parametric method of separation between heavy and light groups of nuclei using the ’knee-like’ approximation of LDF and taking into account measurement uncertainty.

TAIGA stands for "Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy" and is a project to build a complex, hybrid detector system for ground-based gamma- ray astronomy from a few TeV to several PeV, and for cosmic-ray studies from 100 TeV to 1 EeV. TAIGA will search for "PeVatrons" (ultra-high energy gamma-ray sources) and measure the composition and spectrum of cosmic rays in the knee region (100 TeV - 10 PeV) with good energy resolution and high statistics. TAIGA will include Tunka-HiSCORE (an array of wide-angle air Cherenkov stations), an array of Imaging Atmospheric Cherenkov Telescopes, an array of particle detectors, both on the surface and underground, and the TUNKA-133 air Cherenkov array.

The gamma-ray energy regime beyond 10 TeV is crucial for the search for the most energetic Galactic accelerators. The energy spectra of most known gamma-ray emitters only reach up to few 10s of TeV, with 80 TeV from the Crab Nebula being the highest energy so far observed significantly. Uncovering their spectral shape up to few 100 TeV could answer the question whether some of these objects are cosmic ray Pevatrons, i.e. Galactic PeV accelerators.Sensitive observations in this energy range and beyond require very large effective detector areas of several 10s to 100 square-km. While imaging air Cherenkov telescopes have proven to be the instruments of choice in the GeV to TeV energy range, very large area telescope arrays are limited by the number of required readout channels per instrumented square-km (due to the large number of channels per telescope). Alternatively, the shower-front sampling technique allows to instrument large effective areas and also naturally provides large viewing angles of the instrument. Solely measuring the shower front light density and timing (hence timing- arrays), the primary particle properties are reconstructed on the basis of the measured lateral density function and the shower front arrival times. This presentation gives an overview of the technique, its goals, and future perspective.

Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion quality and gamma-hadron separation power. However, sensitive observations at and above 100 TeV require very large effective areas (10 km2 and more), which is difficult and expensive to achieve.The alternative to IACTs are shower front sampling arrays (non-imaging technique or timing-arrays) with a large area and a wide field of view. Such experiments provide good core position, energy and angular resolution, but only poor gamma-hadron separation. Combining both experimental approaches, using the strengths of both techniques, could optimize the sensitivity to the highest energies.The TAIGA project plans to combine the non-imaging HiSCORE [8] array with small (~10m2) imaging telescopes. This paper covers simulation results of this hybrid approach.

The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV . TAIGA will be located in the Tunka valley, ~ 50 km West from Lake Baikal. The different detectors of the TAIGA will be grouped in 6 arrays to measure Cherenkov and radio emission as well as electron and muon components of atmospheric showers. The combination of the wide angle Cherenkov detectors of the TAIGA-HiSCORE array and the 4-m Imaging Atmospheric Cherenkov Telescopes of the TAIGA-IACT array with their FoV of 10×10 degrees and underground muon detectors offers a very cost effective way to construct a 5 km2 array for gamma-ray astronomy.

The physical motivations and advantages of the new gamma-observatory TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is presented. The TAIGA array is a complex, hybrid detector for ground-based gamma-ray astronomy for energies from a few TeV to several PeV as well as for cosmic ray studies from 100 TeV to several EeV. The TAIGA will include the wide angle Cherenkov array TAIGA-HiSCORE with ~5 km$^{2}$ area, a net of 16 IACT telescopes (with FOV of about 10x10 degree), muon detectors with a total area of up to 2000-3000 m$^{2}$ and the radio array Tunka-Rex.

Imaging Atmospheric Cherenkov Telescopes (IACTs) are one of the key parts of the TAIGA observatory, which is designed to study gamma rays and charged cosmic rays in the energy range of 10^13 eV – 10^18 eV. The current prototype phase comprises three IACTs. The first IACT was fabricated at JINR, Dubna, and started its first commissioning season in the Tunka valley in 2017. The second one has been assembled there in fall 2018, the third structure one is ready for installation in autumn 2019. This report presents the main TAIGA IACT characteristics and results from pointing performance studies in the last 2 seasons. We also describe R&D activities started to fabricate focusing glass mirrors at JINR, and give results for the first prototypes measurements.

The first IACT as part of the gamma and cosmic-ray experiment TAIGA was installed in the Tunka Valley near Lake Baikal in fall 2016. In the following months different systems of the telescope were put into test operation. We started the commissioning phase of operating the telescope in time coincidence with the wide angle integrating air Cherenkov HiSCORE array, which for the time being comprises 28 working stations. We anticipate that the hybrid operation of the non-imaging and imaging telescopes will lead to a cost-efficient, highly sensitive detector operating in the energy range from 30-50 TeV till several PeV. Here we want to report on the first test results of operating the prototype hybrid array. We will focus on the analysis of count rates and image size spectra for all events detected by the IACT and the joint events detected also by the HiSCORE array, comparing these with expectations from MC simulations.

The TAIGA (Tunka Advanced Instrument for cosmic rays and Gamma-Astronomy) observatory is designed to study the gamma ray sources and galactic cosmic rays. It is located in the Tunka Valley 50 km from the lake Baikal (Siberia). The first part of TAIGA called the EAS Cherenkov array TAIGA-HiSCORE currently consists of 28 wide-angle (0.6 sr) stations, distributed over an area of 0.25 km^2. The Crab observation exposure was about 115 hours during the winter seasons of 2016-2017. The expected gamma quanta excess depends on the array energy threshold and a model of the Crab energy spectrum extrapolation to the higher energies. We present preliminary results of experimental data and MC simulations comparison as well as energy threshold and angular resolutions. The experimental data is in a good agreement with the simulations. An excess of events (about 25 events in the region 30-63 TeV) observed from the Crab direction is compatible with the expected one.

36th International Cosmic Ray Conference, Madison, USA, 24 Jul 2019 - 1 Aug 2019; PoS-ICRC2019-320 (2019)., Digital radio arrays are widely used for the low-frequency radio astronomy as well as for detection of air-showers induced by high-energy cosmic rays and neutrinos. Since the radio emission from air-showers forms short broadband pulses with duration of tens nanoseconds, the data acquisition strategies of cosmic-ray and astronomical arrays have significant differences. To perform precise measurement of cosmic rays, the radio array should have absolute amplitude calibration and record the entire electric field on the antenna in the broad frequency range. These requirements are similar to ones defined for the experiments aimed at the detection of weak signal from neutral hydrogen at redshifts of $z$>10, what led us to the application of our experience with Tunka-Rex to this problem. We are developing new experimental setup comprising of four antenna stations, placed on the area of 100 sq.m. Each antenna station consists of two perpendicular loop antennas measuring electric field in the frequency band of 30-80 MHz. The setup records electric fields from all antennas in portions of 50 $\mu$s reaching the spectral resolution of 20 kHz. We expect a flow of redundant data of about 10 GB/day, and plan to exploit this redundancy in order to decrease systematic uncertainty of the measurements by application of digital beam-forming, matched filtering and RFI suppression with neural networks. In the present contribution we describe the design and calibration of the setup, expected performance and data analysis techniques.

The first imaging atmospheric Cherenkov telescope as a part of the TAIGA (Tunka Advanced Instrument for cosmic rays and Gamma Astronomy) detector was put into commission in the Tunka valley in December 2016. The reflector of the telescope follows the Davis-Cotton design. It is composed of 34 glassmirror tiles, each of 60 cm diameter, and has a diameter of 4.3 m. The focal length is 4.75 m. The imaging camera includes 560 photomultiplier-based pixels, providing a FoV of ~10×10 degrees. The imaging camera is made by using a modular principle and includes trigger, data acquisition and processing systems based on MAROC3 chips. The slow control system monitors the count rate and the PMT anode currents as well as controls the high voltage. For monitoring performance of the camera a dedicated calibration system based on nanosecond pulsed LED light source was developed.