Fighting a speeding ticket that the cop did not clock my exact speed but based it on assumption.

I recently got sited for 2 tickets in Newark,De for running a stop sign and for unreasonable speeding; i am planning on going to court to fight the unreasonable speeding because the cop gave me the ticket based on the fact that she said she had to do 90 MPH to catch upto me after i run the stop sign so she assumed i was doing atleast 70 MPH on a 35 MPH so she wrote the ticket for unreasonable seeding. In my defense the road is kind of wavy so i was planning on taking picture and showing it as evidence that there is no way i could be doing 70 MPH on that road. Do i have a case and also do i need to hire a lawyer for a traffic case like this. Please advice