They are constant bank angle turns. The requirement in addition making the bank constant is also to keep the IAS constant at 100 KIAS.
You just fly figure 8's and maintain these conditions until the aircraft system tell you it has the data it needs. Very much like advanced compass system in boats these days.
And again, the L2 has mass, that needs to be accelerated to keep the same IAS going into downwind. See post 27 in this thread