TWP/SKYRAD/C2 - Tracker failure

Tracker failed on 6/16/2011. Ops replaced with a spare tracker. The affected instruments 
are the 8-48 (down_short_diffuse) and NIP (direct_normal) shortwave instruments.

The down_long_hemisp1 and 2 (PIR1 and PIR2) performance may have been affected by exposure 
to direct sun.

• inst_down_long_hemisp1_dome_temp
• down_short_diffuse_hemisp_min
• inst_down_long_hemisp2_tp
• down_short_diffuse_hemisp
• inst_down_long_hemisp1_case_temp
• short_direct_normal_std
• short_direct_normal_max
• short_direct_normal_min
• down_short_diffuse_hemisp_max
• down_short_diffuse_hemisp_std
• down_long_hemisp1_std
• down_long_hemisp1_max
• inst_down_long_hemisp2_dome_temp
• inst_down_long_hemisp1_tp
• down_long_hemisp1
• down_long_hemisp2_std
• inst_down_long_hemisp2_case_temp
• down_long_hemisp2_max
• down_long_hemisp1_min
• short_direct_normal
• down_long_hemisp2
• down_long_hemisp2_min

• inst_down_long_hemisp2_tp
• inst_direct_normal
• inst_diffuse
• inst_down_long_hemisp1_tp
• inst_down_long_hemisp1_case_resist
• inst_down_long_hemisp2_case_resist
• inst_down_long_hemisp1_dome_resist
• inst_down_long_hemisp2_dome_resist