Looks like you are getting in the ball park and the best thing that I can say is to keep at it.
When you are calling, try to look at everything in general and nothing in partiicular making sure to use all of your peripial vision. You will be suprised at how quickly you can pickup movement when practicing this. those Coyotes blend in so well that subtle movement will be your best que.
If you move your head at all, do it slowly like you have a stiff neck as the Coyote also picks up movement quickly!
Sounds like you are doing ok all in all. You did have the one that wouldnt cross the ice but the 150yds sounds like fair rifle range. Might have brought it in closer with some coaxing with a squeaker or even lighter higher pitched calling. You will get used to reading their intent via the reactions that you are seeing as you call more and more in.
Bad part is that now you are hooked and you may be doing this the rest of your life.