ELEVATION ANGLE ERROR 



411 



IW) MAY JUUf SEFT 



Month of the Year 



IW) NAT JULY S£PT NW 



Month of the Year 



oeoo I2X leoo 



Hour of the Day 



0400 oeoo 1200 K 



Hour of the Day 



Figure 9.11. Annual and diurnal cycles of Ns /or Bismarck, N.Dak. 



