NSA/GNDRAD/C1 - PIR thermopile instantaneous values intermittently read zero

GNDRAD intermittently reported false zero values for
the third instantaneous value (50 sec after the
minute) of the PIR thermopile voltage.

• pir1_voltage

NSA/GNDRAD/C1 - Noisy PIR Data

During the period referenced, the ground PIR was noisy in comparison to the sky PIR data.  
At the end of November, the noise increased to roughly 10 W/m2 from peak to peak.  After 
12/23/98, the noise decreased in amplitude but still had noisy patterns.  

On 01/17-18/99, there was an increase again in the noise level (4 GMT 01/17 - 5 GMT 
01/18). During this period the gndrad IRT data also exhibited noise patterns (the IRT was not 
operational).

In February, the instrument exhibited large noise variations again.  On 02/16, a wiring 
problem was corrected and the noise dropped back to 1-5 W/m2.  However, the noise levels 
began to increase again.

• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/GNDRAD/C1 - IRT not connected

The IRT was unplugged from the Zeno data logger on 12/10/1998 for a interference test and 
when it was plugged back in on 12/22, the connector at the data logger was damaged. The 
data logger and connecter were replaced on 1/20/1999.

• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• sfc_ir_temp_std
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)

NSA/GNDRAD/C1 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C.  Measurements of surface temperature were over-estimated when instrument was below 
freezing.

Data will be reprocessed, but users can correct data using the following correction 
factor:

If T_reference < -5?C, then

  IRT_corrected = (IRT_original - 32.993K)/0.87238

where T_reference can be estimated with the ambient temperature (e.g. 
inst_up_long_hemisp_dome_temp or inst_up_long_dome_temp)

• irt1_max
• irt1_min
• irt1_sd
• irt1_mean