| Subject: | SGP/SIRS/E3 - Instrument leveling and tracker problem |
| DataStreams: | sgpsirsE3.b1, sgpsirs20sE3.a0
|
| Description: | Asymmetry between measured downwelling shortwave and derived downwelling shortwave
hemispheric in the afternoon began late in fall and became more apparent as the sun moved higher
in spring. This can happen when the PSP is unlevel or when the NIP is not tracking well.
The PSP level was corrected and the clock on tracker was reset. Mentor suspects PSP was
unlevel during this time range causing the discrepancy in measured vs. calculated
downwelling shortwave hemispheric data. |
| Suggestions: | Use derived downwelling shortwave hemispheric constructed from downwelling diffuse
hemispheric and direct normal data as described in the SIRS instrument handbook |
| Measurements: | sgpsirs20sE3.a0: - inst_global
- inst_direct_normal
- inst_diffuse
more
sgpsirsE3.b1: - short_direct_normal_min
- down_short_diffuse_hemisp_std
- down_short_diffuse_hemisp
- down_short_diffuse_hemisp_max
- down_short_hemisp_max
- down_short_hemisp_std
- short_direct_normal_std
- short_direct_normal_max
- short_direct_normal
- down_short_diffuse_hemisp_min
- down_short_hemisp
- down_short_hemisp_min
more
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