Robinson's tag shows that he is across the desert and is northeast of Lake Chad. His tag powered-up 24 hours earlier than we were expecting, presumably the result of the solar panel on the tag getting plenty of sunshine during the crossing.
He began his desert flight from the Libyan coast around 8.00am on 25 July, by 9.00pm on the same day he was halfway across. His tag powered-up again just before 10.00am on 26 July, showing he was 805km (500 miles) further south and west and heading towards Lake Chad. The last location from his tag was just before 5.00pm on the same day; he was just 69km (43 miles) from the lake.