UMass Boston

VIIRS User Guide Collection 1

This Guide is a living document that describes the VIIRS BRDF and Albedo Products. The purpose of the document is to give the potential user an understanding of the VNP43 products and the current state of the data in those products.

Note: Users are urged to use the band specific quality flags to isolate the highest quality full inversion results for their own science applications. 

The Collection 1 VNP43D products are retrieved from the 1km BRDF parameters in VNP43MA1. Because of the large size of the products, each Parameter for each of the 9 VIIRS M bands, the 3 broadbands, and the Day Night Band (DNB) are stored in a separate VNP43D file. Therefore VNP43D1 is the VIIRS (blue) band M1 fiso parameter, VNP43D2 is the VIIRS band M1 fvol parameter, VNP43D3 is the VIIRS band M1 fgeo parameter, and then VNP43D4 is the VIIRS band M2 fiso parameter and so on through to VNP43D39. VNP43D40-VNP43D51 are the 30arc second BRDF/Albedo Quality values, the Local Solar Noon values, the Valid Observations of the M bands (M1–M5, M7–M8 and M10–M11) and the DNB, then Snow Status and the Uncertainty. VNP43D54-VNP43D66 are the black sky albedos (BSA) at local solar noon for the 9 VIIRS M bands followed by the three broadbands, then the DNB. VNP43D67-VNP43D79 are the white sky albedos (WSA) for the 9 M bands, the three broadbands, and the DNB. Finally VNP43D80-VNP43D89 provide the 30arcsecond NBAR values (at local solar noon) for the 9 VIIRS M bands and the DNB.

Note that the Collection 1 VIIRS VNP43 products are retrieved daily and represent the best BRDF possible based on 16 days’ worth of inputs with the day of interest (the center day of the retrieval period) particularly emphasized. This change is in response to user requests.