My question involves a speeding ticket from the State of: Mass

I was clocked at 47 in a 30 mph zone.

I generally never speed and have a safe driving record.

This ticket was issued and when the officer asked me what the speed was in the zone, I thought for sure it was 35; but it was 30. Just as he caught me it changed from 35 to 30, which I now know since I drove back over to check it.

I was speeding, but I only saw 40 mph, and thought it was a 35 mph zone.

What is the best thing to say, plea, and ask for one time pardon of this ticket. It is a 170 fine, which is excessive in my opinion.

The officer who stopped me was cold and distant, and mumbled a bit so I didn't even understand what he was saying after he issued the ticket. I did not argue since I knew it would not help the situation.

I was speeding, but in all honesty feel it was a bit of a trap, and I wonder if this police officer (using radar) may have "embellished" my actual speed.
Of course I can't say, but it's a feeling. I have never been treated in such an unfriendly manner, and twice he asked me if I had seen him over to the side of the road. Obviously not, or perhaps I didn't think twice since I thought i was within the range of speed, and was shocked when he told me I was 17 over.

I know to dress professionally, show remorse, be respectful, and of course I plan on doing all that.....but is there anything else?

Also, if the officer does not show up, does it matter?

I am upset about the way he treated me, and the fact that I was speeding, but not overly so, and feel he kind of set me up, both in the zone and by upping my actual speed. But I know it's impossible to prove, and the judge will believe him over me.

But thanks for any help you can offer.