the pattern looks pretty easy. what i would do is make your chain stitch, to the lenghth that you want, then do the double crochet(as that is what it looks like.) then after each row what you do is add another double crochet to the beginning and end of the row, increase this every other row and it should come out in a half circle pattern. as for the top it looks like that was added afterwards again using the same technique. good luck and hope that helps.