One objective of BOREAS is to further the understanding of the spectral bi-directional reflectance of typical boreal ecosystem stands in the visible/near-infrared regime. An essential input for any canopy BRDF model is an accurate estimate of the average understory reflectance, both for sunlit and shaded conditions. These variables can be expected to vary seasonally because of species-dependent differences in the phenological cycle of foliar display. In response to these requirements, the average understory reflectance for the flux tower sites of both the NSA (Thompson, Manitoba) and the SSA (Candle Lake, Saskatchewan) Study Areas (NSA and SSA) was observed throughout the year during five field campaigns. This was done by measuring the nadir reflectance (400 to 850 nm) of sunlit and shaded understory (vegetation and snow cover) along a surveyed LAI transect line (Chen, RSS-07) at each site near solar noon and documenting a average site reflectance. Comparisons between sites reveal differences in the green and infrared regions of the spectra, because of the differing species in the understory for each site. Temporal (seasonal) variation for each site was also observed, indicating the changing flora mixtures and changing spectral signatures as the understory matures during the growing season.

Contains forest understory spectral reflectance data collected by BOREAS TE-09 at the ground level in the Old Jack Pine, Young Jack Pine nd Young Aspen boreal forest sites in the NSA.

Spectral reflectance of the forest understory at the ground level, in three boreal forest sites of Northern Manitoba (56 degrees N latitude and 98 degrees W longitude), were obtained and analyzed. The objective of the study was to estimate light levels inside the forest canopy and to link these estimates with airborne images taken above the canopy, in order to tie the photosynthetic experiments and models with the remotely sensed measurements. The Boreal Ecosystem-Atmospheric Study (BOREAS) Terrestrial Ecosystem (TE)-09 project contained several sub-projects designed to work together to meet this goal: a high-resolution canopy modeling component, extensive measurements of canopy architecture and structure, photometric measurements inside the canopy, and spectral measurements of both the canopy and the understory.

Contains site averaged reflected radiance and reflectance values from barnes MMR taken from helicopter.

This data set contains maps of surface reflectance and vegetation parameters derived from imagery collected by the POLDER instrument over BOREAS conifer tower sites in the Southern Study Area (SSA) during 1994. The POLDER imagery provided in this data set was collected on June 1 and July 21, 1994, from the NASA C-130 aircraft platform.

The RSS-03 team acquired helicopter-based measurements of forested sites during BOREAS with a Barnes MMR. The data were collected in 1994 during the rhree BOREAS IFCs at numerous tower and auxiliary sites in both the NSA and SSA. The 15-degree FOV of the MMR yielded approximately 79 m from the 300 m altitude ground resolution. The MMR has seven spectral bands that are similar to the Landsat TM bands, ranging from the blue region to the thermal. Note:

The BOREAS RSS-03 team collected multiple remotely sensed data sets from the NASA UH-1 helicopter. This data set includes helicopter-based radiometric measurements of forested sites acquired during BOREAS made with an SE-590 processed to reflectance factors. The data used in this analysis were collected in 1994 during the three BOREAS IFCs at numerous tower and auxiliary sites in both the NSA and the SSA. The 15-degree FOV of the SE-590 yielded a ground resolution of approximately 79 m at the 300-m nominal altitude.

The BOREAS RSS-01 team collected surface reflectance and transmittance data from three forested sites in the SSA. This data set contains averaged reflectance factors and transmitted radiances measured by the PARABOLA instrument at selected sites in the BOREAS SSA at different view angles and at three wavelength bands throughout the day. PARABOLA measurements were made during each of the three BOREAS IFCs during the growing season of 1994 at three SSA tower flux sites as well as during the FFC-T. Additional measurements were made in early and mid-1996 during the FFC-W and during IFC-2.

The BOREAS RSS-17 team acquired and analyzed imaging radar data from the ESA's ERS-1 over a complete annual cycle at the BOREAS sites in Canada in 1994 to detect shifts in radar backscatter related to varying environmental conditions. This data set consists of dielectric constant profile measurements from selected trees at various BOREAS flux tower sites. The relative dielectric constant was measured at C-band (frequency = 5 GHz) as a function of depth into the trunk of three trees at each site. Measurements were made during April 1994 with an Applied Microwave Corporation field PDP fitted with a 0.358-cm (0.141-inch) diameter coaxial probe tip.

Contains helicopter SE-590 measurements taken by RSS-03.