Experts told a jury at Bolton Crown Court that Damien Myerscough's 998cc Yamaha was travelling `between 35 and 45mph' when it rammed into the side of a Volkswagen Golf, on Church Street, in Ainsworth, Bury - a 30mph road.
Pc Mark Cheetham, from the police's collision reconstruction unit, said Pc Myerscough was thrown an estimated 26 metres over the car.
His bike landed on the back of Lyndsay Oldham, 43, of Edgeworth Avenue, Ainsworth, who was out shopping with two of her three children.
The court heard the force of the impact threw her against a stone wall. Mrs Oldham, an IT worker at Bury council, was pronounced dead at the scene.
Pc Myerscough, 42, from Ainsworth, who serves with Greater Manchester Police's tactical aid unit, denies causing death by dangerous driving.
Pc Cheetham said he calculated the alleged speed by combining the point of impact with the distance Pc Myerscough came to rest away from it.
But he told Bolton Crown Court: "It could be slightly more than that."
The court has heard that Pc Myerscough's bike had no tax, a slack chain and had been fitted with an illegal exhaust to make it louder.
Earlier in court, witness and motorbike enthusiast Dean Watts said he heard the bike `open up' or accelerate before the collision.
He said he saw Pc My-erscough overtake one vehicle in a convoy of four and told the jury: "It was going very fast."
The jury was told that after the collision, Mr Watts ran over to the badly-injured Pc Myerscough then heard him say: "I'm doomed. Was it my fault? That's it. That's my career gone. I'm a police officer."
Mrs Oldham's two children David, then 17, and Emma, 14, escaped serious injury, the court was told.
PC Myerscough suffered a badly broken leg and is appearing in court in a wheelchair.
Proceeding
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