Versions Compared

Old Version 1

changes.mady.by.user Tom Horst

Saved on

compared with

New Version Current

changes.mady.by.user Tom Horst

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: Migrated to Confluence 5.3

...

I begin with a comparison of the SPN1 global radiation to Rsw.in from the K&Z CM21 at NEAR and FAR..

I need a latitude and longitude for editing the solar radiation data by sun angle.

Cannot currently access the GPS lat/lon, so use those measured by Oncley at the end of the project.  This is not all that critical for FLR and NEAR.

For the FLR radiation stand, SPO measured

latitude =  35d 01.680' = 35.028

longitude = 111d 01.353' = -111.05588

Then

At NEAR, select data with sun elevation greater than 15 degrees (this limit is not critical).  The median ratio of Rsw.global/Rsw.in = 0.9938.  I note, however that there is hysteresis in the plot of Rsw.in.global versus Rsw.in.  This is consistent with the observation that the up-facing radiometers at NEAR were not perfectly leveled because of problems with the radiometer mounting device.

Section
Column

Image Added:

Column

Image Added

At FLR we select data with sun elevation greater than 20 degrees (to clear the sidewalls).  The median ratio of Rsw.global/Rsw.in = 1.0358, which is perhaps higher because the bird droppings obscured Rsw.in at times.  I conclude that Rsw.global could be used as a reasonable surrogate for Rsw.in during those times.   Rsw.in.flr data were deleted from Oct 14-20 when the residuals from a linear fit of Rsw.global.flr vs Rsw.in.flr exceeded 20 W/m^2, as indicated by the highlighted data in the right-hand plot below.  After deleting that Rsw.in.flr data, the linear fit changed slightly to Rsw.global.flr = 1.029*Rsw.in.flr + 1.07 W/m^2.

Section
Column

Image Added

Column

Image Added