dump1090.c line 298. Can we save memory of magnitude by 2?

Hi,

In dump1090.c line 298:
"
(Modes.magnitude = malloc(Modes.data_len*2)) == NULL) {
"
Why there is "times 2"? Two bytes (I&Q) in Modes.data generates one item in magnitude, and one magnitude item (uint16_t) cost two bytes. So I think magnitude needs exactly the same memory size as data.

Or do I miss sth?