National Astronomical Research Institute of Thailand (Public Organization) initiated a national flagship project in 2017 for development of radio astronomy and geodesy in Thailand. In this project, a 40-m Thai National Radio Telescope (TNRT) and a 13-m VLBI Global Observing System (VGOS) radio telescope as its co-location are constructed in Chiang Mai. The 40-m TNRT is the largest telescope for radio astronomy in South-East Asia. Its flexible operation with a wide-coverage of observable frequencies 0.3-115 GHz will allow us to uniquely contribute to the time-domain astronomy as well as carry out unbiased surveys for a wide variety of science research fields, which were published in a white paper. Within the framework of collaboration with VLBI arrays in the world, TNRT will drastically improve the imaging quality and performances based on its unique geographical location, for both radio astronomy and geodetic VLBI studies in South-East Asia for the first time. On-going commissioning of TNRT particularly in the L-band system (1.0–1.8 GHz) is introduced as well as vision for establishment of forthcoming regional VLBI networks based on TNRT: Thai National VLBI Array and South-East Asian VLBI Network in collaboration with Indonesia, Malaysia, and Vietnam.

Continuous gravitational Waves (CWs) are a very promising, not yet detected, and interesting class of persistent and semi-periodic signals. They are emitted mainly by rapidly rotating asymmetric neutron stars, with frequencies that are well covered by the [10-3 000] Hz range of the advanced LIGO-Virgo detectors. Due to the expected small degree of asymmetry of a neutron star, the search for this kind of signals is extremely challenging, and can be very computationally expensive when the source parameters are not known or not well constrained. CW detection from a spinning neutron star will allow us to characterize its structure and properties, making this source an unparalleled laboratory for studying several key issues in fundamental physics and relativistic astrophysics, in conditions that cannot be reproduced on Earth. The most recent methodologies used in CW searches will be discussed, and the latest results from the third advanced LIGO-Virgo observational run will be presented. A summary of future prospects to feasibly detect such feeble signals as the detector performance improves, and ever-more-sensitive and robust data-analysis algorithms are implemented, will be also outlined.

Digital signal processing is one of many valuable tools for suppressing unwanted signals or inter-ference. Building hardware processing engines seems to be the way to best implement some classes of interference suppression but is, unfortunately, expensive and time-consuming, especially if several miti-gation techniques need to be compared. Simulations can be useful, but are not a substitute for real data. CSIRO’s Australia Telescope National Facility has recently commenced a ‘software radio telescope’ project designed to fill the gap between dedicated hardware processors and pure simulation. In this approach, real telescope data are recorded coherently, then processed offline. This paper summarises the current contents of a freely available database of base band recorded data that can be used to experiment with signal processing solutions. It includes data from the following systems: single dish, multi-feed receiver; single dish with reference antenna; and an array of six 22 m antennas with and without a reference antenna. Astronomical sources such as OH masers, pulsars and continuum sources subject to interfering signals were recorded. The interfering signals include signals from the US Global Positioning System (GPS) and its Russian equivalent (GLONASS), television, microwave links, a low-Earth-orbit satellite, various other transmitters, and signals leaking from local telescope systems with fast clocks. The data are available on compact disk, allowing use in general purpose computers or as input to laboratory hardware prototypes.

The ALMA (Atacama Large Millimeter/sub-millimeter Array) is the large interferometer that will consist up to 64 high-precision antennas operating in the 31.3 – 950 GHz frequency range. In this range unique observations in cosmology, cold universe, galaxies, stars and their formations, and so on are expected. Among these objectives there is a unique possibility to observe the Sun and to address outstanding issues of solar physics. The ALMA is shortly described and then the new ESO-ALMA European node (ARC) built at Ondřejov Observatory is presented. The new ARC is the only one in Europe oriented to solar physics. The requirements and limitations for ALMA solar observations, as well as some examples of possible solar-oriented ALMA projects, are mentioned.

The Darwin and TPF-I missions are Infrared free flying interferometer missions based on nulling interferometry. Their main objective is to detect and characterize other Earth-like planets, analyze the composition of their atmospheres and their capability to sustain life, as we know it. Darwin and TPF-I are currently in study phase. A number of mission architectures of 3 and 4 free flying telescopes are evaluated on the basis of the interferometer's response, ability to distinguish multiple planet signatures and starlight rejection capabilities. The characteristics of the new configurations are compared also to the former, more complex Bowtie baseline architectures as well as evaluated on base of their science capability.

Nulling interferometry is one of the promising techniques for the study of extra terrestrial planets. This technique will be applied in the future space missions Darwin and TPF-I, and from the ground with GENIE. The nulling interferometry techniques require high symmetry of the interfering beams, to obtain the required contrast (typically $10^6$ to detect terrestrial exo-planets in the thermal infrared). In this paper we consider the polarization symmetry issue, such as polarization rotation and polarization phase shifts occurring on slightly misaligned optics. We study the consequences of these symmetry requirements on a nulling interferometer design. We find the relation between the misalignment tolerances and the achievable nulling, and we show that this tolerance is highly dependent on the interferometer configuration (the way beams turn right, left, up or down in the interferometer arms). It is typically of the order of the arcminute (not the arcsecond) for a $10^6$ contrast. We present a analytical and numerical analyses.

In order to evaluate and develop mission concepts for a search for Terrestrial Exoplanets, the European Space Agency has prepared a list of potential target systems. In this paper we present the criteria for selecting potential target stars suitable for the search for Earth like planets. We also establish the habitable zone for the stellar systems. Planets found within these zones would be potentially able to host complex life forms. The Darwin target star catalogue was created from the Hipparcos catalogue by examining the information on distance, spectral classification, multiplicity and stellar variability. Additional information on the targets stars including spectral type, metallicity, X-ray luminosity, rotation and Strömgren photometry from several other catalogues are included to determine the target star sample. Design constraints of the mission are added to derive a final target star catalogue of 262 target stars excluding and 447 target stars including M stars for the Darwin mission. We also discuss the completeness of sample for different classes of stars.