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Numerous activities are underway at HartRAO to improve on the accuracy of current geodetic techniques, to add new instruments and techniques and generally strive towards the GGOS goal of long-term millimetre-level accuracy in the network. Towards this end, construction of a modern 13.2 m VGOS radio telescope is underway. It is envisaged that the radio telescope will be commissioned by July 2017. A local automated site tie system is also in the final stages of installation and should be operational by the end of 2016. HartRAO has been designated as the host facility for a new Russian SLR station in South Africa. The 26 m radio telescope's efficiency was recently doubled by the first ever K-band observations at 2 Gbps. Co-Authors: Roelf Botha, HartRAO/NRF Ludwig Combrinck, HartRAO/NRF Aletha de Witt, HartRAO/NRF Christopher Jacobs, JPL, Caltech/NASA Work sponsored in part by U.S. Government AUTHOR: MARISA NICKOLA HARTRAO/NRF NEW DEVELOPMENTS AT THE HARTEBEESTHOEK RADIO ASTRONOMY OBSERVATORY ABSTRACT Philip Mey, HartRAO/NRF Pieter Stronkhorst, HartRAO/NRF Jonathan Quick, HartRAO / NRF 5th International VLBI Technology Workshop (IVTW 2016) MIT Haystack Observatory in Westford, Massachusetts, USA Type to enter text • Site infrastructure: water, electricity and network connectivity being finalised • Tender has been awarded for civil works • Construction to commence October 2016 • Electrical supply has already been connected on site • Water supply and network connections to follow • First step during civil works - site layout: surveying site perimeter, clearing, establish- ing slight slope for rainwater to run away from buildings • Site will be fenced off to control access • Antenna top structure set to arrive in January 2017, once construction has been com- pleted • Anchorage ring - interface between static concrete tower and movable top structure - first part to arrive on site • Anchorage ring will be positioned and cast in place by December 2016 • Concrete will be left to cure until top structure is assembled in February 2017 • Radio telescope to be commissioned by July 2017 • Webcam will capture construction process with live footage available on HartRAO website at www.hartrao.ac.za CONSTRUCTION OF 13.2-M VGOS RADIO TELESCOPE Figure 1: Mini-sub (offloading and installation) Figure 2: Network trench and installation of conduits. Figure 3: Anchorage ring. Figure 4: VGOS project manager, Philip Mey, inspecting site levelling by Hamm 30 ton excavator (on left) and drum roller/ compactor (on right). LOCAL AUTOMATED TOTAL STATION • Local automated site tie system is being installed • Uses Leica MS50 Multi-station mounted on reference pier • Line-of-site to all major geodetic systems on site • System will perform daily automated measurements to determine daily product at mm-level • Daily vector ties between geodetic and astronomical instruments will better overall accuracy of equipment • Should be operational by end of 2016 Figure 5: The local automated site tie system is nearly ready to start operation. NEW VLBI AND SLR DEVELOPMENTS Figure 6: New Cryogenic 22-GHz receiver at HartRAO. HartRAO is a facility of the National Research Foundation (NRF), South Africa. U.S. government sponsorship is acknowledged for NASA portions of this work. Copyright 2016. All rights reserved. • Russian SLR/GNSS equipment at HartRAO will be installed, main- tained and operated under support of the Space Geodesy pro- gramme • A Russian SLR Compact Laser-Optical System for Spacecraft collo- cated with GLONASS GNSS receiver and antenna will be installed • GNSS will cater specifically for positioning using the GLONASS con- stellation • Factor of five improvement in HartRAO 26-m telescope sensitivity at 22 GHz, with installation of cryogenically cooled K-band receiver • Efficiency of the HartRAO 26-m telescope was recently doubled, with first ever K-band observations at 2 Gbps • Combined upgrades at 22 GHz tripled the resolution of the instrument over previous work at 8.4 GHz Figure 7: Construction of GNSS pillar at HartRAO.
