|Submitter:||APERTIF team (Wim van Cappellen)|
|Description:|| At the end of this already very exciting year, the APERTIF team proudly announces that the first fringes between the DIGESTIF Focal Plane Array and multiple MFFE equipped dishes of the WSRT have been successfully measured.|
For this purpose, the IF outputs of 3 MFFE dishes (RT1, RT3 & RT4) are connected to the DIGESTIF back-end at RT5. After a short but intensive period of debugging the first fringes have been measured. The figure shows the measured fringes between one FPA element and multiple MFFE dishes at 144m and 288m and 576m baselines over a period of 200 seconds. As expected, the fringe frequency doubles when the baseline is doubled. All dishes were tracking 3C286. The data is taken at 1420 MHz with a bandwidth of 20 MHz and an integration time of 0.025 s per point.
The possibility to measure correlations between DIGESTIF and other dishes will enable a more detailed evaluation of FPA performance and to test the performance of FPA's in interferometric imaging.
These great results have only been possible through the collaborative efforts of the complete APERTIF team, and in particular Laurens Bakker, Albert-Jan Boonstra, Hans van der Marel and Harm-Jan Stiepel. A special word of thanks to the great support of Gyula Józsa and the Observers Yuan Tang, Jurjen Sluman and Geert Kuper who used all their creativity to squeeze these observations in the WSRT schedule.