Our Research

Techniques for Radio Weak Lensing Meeting - 6-7 October 2014


Thank you to everyone who attended the first dedicated meeting for radio weak lensing!
Talks, a participants list and programme from the meeting are available below.
If you are interested in participating in or organisation of a radio GRavitational lEnsing Accuracy Testing (GREAT) programme, please register on the radioGREAT wiki


Techniques for Radio Weak Lensing 2014 radioGREAT logo RadioNet logoEC logo
RadioNet3 has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 283393

The SKA has the potential to be competitive with other large facilities such as Euclid and LSST in constraining the Dark Energy equation of state to the 'Stage IV' level specified by the Dark Energy Task Force by measuring the weak gravitational lensing of background galaxies. Furthermore, measuring a weak lensing signal in the radio presents a number of unique advantages, probing higher redshifts than optical and near-IR weak lensing and in using novel techniques to overcome systematic effects which can severly limit optical/NIR experiment's ability to do precision cosmology. Leading up to the SKA a number of surveys, including SuperCLASS, CHILES-con-pol and VLASS will provide data to demonstrate our ability to do weak lensing in the radio and probe the micro-Jy source populations useful for weak lensing.

However, extracting a weak lensing signal from data is hard, requiring the measurement of galaxy morphologies to exquisite accuracy. In the optical/NIR lensing community the Shear TEsting Programme (STEP) and GRavitational lEnsing Accuracy Testing (GREAT) challenges have run for ~10 years, challenging the community to blindly measure galaxy shapes in simulated data. These challenges have been crucial in identifying and solving the data analysis problems in image-plane weak lensing and the necessary levels of fidelity are now beginning to be achieved. For data from radio interferometers we are only now beginning this process, which will require processing of enormous data volumes and implementation of new image analysis techniques

The aim of this meeting is be to bring together people working on both radio data analysis and imaging techniques with those working on weak lensing shape measurement techniques and begin to address the problem of performing cosmic shear measurements using radio data. The meeting will include tutorials from each group directed towards the other, short talks on the research which has so far been conducted in shape measurement for radio weak lensing and form an executive/organising committee for a GREAT challenge for radio data.

The Scientific Organising Committee for this meeting are Ian Harrison (Manchester, UK), Michael Brown (Manchester, UK), Prina Patel (University of the Western Cape, South Africa) and Barney Rowe (UCL, UK)

Programme and Participants

A programme is available here.
A list of participants is avialable here.

Talk Slides

Please e-mail your talk slides to Ian Harrison (ian 'dot' harrison 'dash' 2 'at' manchester.ac.uk) with the subject line "[RWL 2014 Talk Slides]" before the beginning of your session, to allow us to upload them to the presentation computer and for them to be viewed by remote participants. PDF files are strongly preferred

Ian Harrison: Introduction

Joe Zuntz: Weak Lensing Shape Measurement

Prina Patel: A Brief History of Radio Weak Lensing

Barney Rowe: The GREAT3 Challenge

Ivan Marti-Vidal: UVMULTIFIT

Julien Girard: LOFAR and SKA Sparse Image Reconstruction

Sarod Yatawatta: ExCon: Exascale Imaging

Marzia Rivi: Galaxy Shape Measurement for Weak Lensing with the SKA

Constantinos Demetroullas: A galaxy-galaxy lensing measurement by cross-correlating optical and radio data

Jimmy Tarr: Direct Shear Mapping from Visibilities

Ben Metcalf: Gravitational Lensing of Cosmological 21cm Emission

Lee Whittaker: Separating Weak Lensing and Intrinsic Alignments Using Radio Polarisation

Sphe Makhathini: CEILING-KAT: Online End-to-End Simulator for SKA Phase-I and its Pathfinder Missions

Internet Access

Guest internet access will be available on arrival for external participants.


Travel information and meeting venue

Travel to the meeting venue

The meeting is being held in the Alan Turing Building of the University of Manchester. A map of the University campus, including the railway station, is available here; the Turing building is number 46. The venue is the Lovell seminar room, room 3.225 on the third floor. The same link also has maps of the city centre, which is about 30 minutes' walk from the Turing building.

By train

The nearest train station is Manchester Piccadilly (the main railway station in Manchester), with timetables and booking services available here. Walking directions from the Picadilly station South exit (down the escalators to your left as you exit the platforms) are available here, with the walk taking around 20 minutes

By car

The easiest way to get directions is to enter "M13 9PL" as your destination postcode into Google Maps or your GPS unit. This will probably bring you to Oxford Road, which is in the centre of Manchester. If you are coming up from the South on this road, then you will pass a large circular building on your right before passing under a red brick building. Take the right after this red brick building. If coming in from the North, then turn left just before a red building going over the road. At the traffic lights down this road turn right and you will come to the Aquatics car park. You can park here (the cost is £10 per day); the Alan Turing Building is the large dark grey building directly to the South of this car park.

By aeroplane

The closest airport is Manchester International Airport. There are regular (around every 15 minutes) direct trains from Manchester Airport's railways station to Manchester Piccadilly (see above).

Liverpool John Lennon Airport (about 35 miles from Manchester) offers cheaper Easyjet flights; there is a direct Terravision bus link available from Liverpool Airport to Manchester City Centre.

General travel information

Regular bus routes within Manchester and the surrounding areas leave from Piccadilly Bus station. Further travel information on Buses, trams and trains within the Greater Manchester area can be found at here, or via telephone 0161-228-7811 (8am - 8pm).Information and tickets are also available from GMPTE Travel-shops at the bus station.

Taxis. If you need to use a taxis any black hackney cab can be hailed at the road side or picked up at a taxi rank. Do not attempt to hail a minicab. Mini-cabs will not normally pick you up and if they do they, and you, are not covered by any insurance. Minicab have to be pre-booked via telephone call (phone numbers of a few mini-cabs firms - Taxifone: 0161-236-2322,Village Private Hire: 0161-237-3383, Radio Cars: 0161-236-8033). Uber taxis are also available, with £10 free credit given by the code IANH89.


You should book your own accommodation, of which there is a plentiful supply within walking distance of the University. Nearby ones include: All three are about 20 minutes' walk from the meeting venue. If you are searching for a hotel, the University postcode is M13 9PL.