Name of the Project
MeerKAT extension (MeerKAT+) project.

Location
Karoo region of the Northern Cape, South Africa.

Project Owner/s
South African Radio Astronomy Observatory (SARAO).

Project Description
MeerKAT is intended as a precursor to the giant Square Kilometres Array (SKA) radio telescope, which will be stationed in South Africa and Australia. Meerkat is intended to be integrated into the midfrequency component of the SKA (known as SKA-Mid); Australia will host the low-frequency component (SKA-Low).

The SKA arrays will create the most sensitive radio telescope ever built, with the Phase 1 SKA-Mid planned to have 197 dish antennas, which will include the 64 dishes of the original MeerKAT. SKA-Low will have about 131 000 simple aerial antennas.

MeerKAT+ will expand the MeerKAT array by 20 dishes.

This increase will allow for the maximum distance between the array’s dishes to be dramatically increased from 8 km to about 20 km, which will significantly increase its sensitivity and the resolution of the radio images that it will capture.

The new dishes for MeerKAT+ will be built according to the specifications agreed for the SKA-Mid Phase 1 dishes. 

The expanded array will be focused on sky survey programmes, covering the southern sky.

A key aim will be the study of transient radar sources, including fast radio bursts and pulsars.

Another priority will be cosmology – the study of individual galaxies and large-scale structures in the universe.

The expansion will also require a tenfold increase in the telescope’s computing power.

Potential Job Creation
Not stated.

Capital Expenditure
R900-million.

Planned Start/End Date
MeerKAT+ is expected to start early science operations in 2024, followed by full science operations.

Latest Developments
South African black-owned construction group Concor has reported on its progress in building the foundations and infrastructure for the MeerKAT extension project, which it is undertaking in conjunction with OptiPower.

Concor started work on the site in September. In addition to the foundations for the dishes, the project includes the construction of roads and other infrastructure.

“With the piling rig on site, October saw our first piles drilled and concrete poured,” Concor contracts manager Stephan Venter has reported.

Soft soil and sandy conditions require that the 20 foundations will be based on piles with a concrete cap; each foundation has eight piles of 750 mm diameter and between 7 m and 11 m deep, he adds.

The MeerKAT is an extremely precise instrument. Consequently, the dishes, including their foundations, have to be positioned with great accuracy. In particular, structures called ‘bolt cages’, to which the dish antenna pedestals are secured, have to be sited with an accuracy measured in fractions of a millimetre. Each bolt cage is galvanised, with a height of 1.7 m, and is built locally to specification.

“In addition to the accuracy, the foundations must ensure that the antennas are able to resist the force of winds, especially as the dish is a wide surface area,” Venter highlights. There is also no room for any vibration of the dish.

The construction crews must achieve all this while emitting the absolute minimum radio frequency interference (RFI), as this would not only disrupt the operation of the current MeerKAT array but could even damage its equipment, which is designed to detect extremely weak radio signals from deep in the universe. RFI can be generated by cell phones, electronics on vehicles and many other pieces of equipment and tools.

Concor has tested and modified all its on-site equipment to comply with the RFI limitations. This includes excavators, trucks, graders, compactors, telehandlers, water bowsers, tractor-loader-backhoes and the company’s specialised concrete batching truck.   

Key Contracts, Suppliers and Consultants
Max-Planck-Gesellschaft (SKA-Mid dish demonstrator); and Concor and OptiPower (construction contract).

Contact Details for Project Information
SARAO, email enquiries@ska.ac.za.