Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
02/20/1997 | 0000 | 03/06/1997 | 1500 | Incorrect |
Subject: | SGP/QCRAD/E2 - Tracker inoperative |
DataStreams: | sgpqcrad1longE2.c2, sgpqcrad1longE2.c1, sgpqcrad1longE2.s1, sgpqcrad1longE2.s2 |
Description: | Solar tracker inoperative. Described in instrument DQR D970310.1. From about 97/02/20 to 97/03/06 (1500 GMT) the solar tracker was inoperative at site E2. We cannot pin down the exact starting time of this failure because of cloudy conditions around 97/02/20. The failure becomes obvious during clear skis at which time the NIP reads zero (i.e., it isn't pointed at the sun) and the downward diffuse radiation is too large (because the diffuse pyranometer is not being shaded). 97/03/03 was a particularly clear day and the diffuse pyranometer reads almost the same as the total downward pyranometer. The fact that they don't read exactly the same - the discrepency is about 75 W/m^2 at solar noon - is indicative of a large sensor calibration problem. This large calibration error is NOT typical of ARM data, rather it is peculiar to this site. |
Suggestions: | Don't use SW direct or diffuse data during these time periods. If "source_BestEstimate_down_short_hemisp" is 0, don't use Best Estimate GSW data. Note that fewer quality checks can be applied accurately to the BestEstimate data. |
Measurements: | sgpqcrad1longE2.s2: more
sgpqcrad1longE2.c2: more sgpqcrad1longE2.c1: more sgpqcrad1longE2.s1: more |