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Solar induced chlorophyll fluorescence has been shown to be increasingly an useful proxy for the estimation of gross primary productivity (GPP), at a range of spatial scales. Here, we explore the seasonality in a continuous time series of canopy solar induced fluorescence (hereafter SiF) and its relation to canopy gross primary production (GPP), canopy light use efficiency (LUE), and direct estimates of leaf level photochemical efficiency in an evergreen canopy. SiF was calculated using infilling in two bands from the incoming and reflected radiance using a pair of Ocean Optics USB2000+ spectrometers operated in a dual field of view mode, sampling at a 30 min time step using custom written automated software, from early spring through until autumn in 2011. The optical system was mounted on a tower of 18 m height adjacent to an eddy covariance system, to observe a boreal forest ecosystem dominated by Scots pine. (Pinus sylvestris) A Walz MONITORING-PAM, multi fluorimeter system, was simultaneously mounted within the canopy adjacent to the footprint sampled by the optical system. Following correction of the SiF data for O2 and structural effects, SiF, SiF yield, LUE, the photochemicsl reflectance index (PRI), and the normalized difference vegetation index (NDVI) exhibited a seasonal pattern that followed GPP sampled by the eddy covariance system. Due to the complexities of solar azimuth and zenith angle (SZA) over the season on the SiF signal, correlations between SiF, SiF yield, GPP, and LUE were assessed on SZA <50° and under strictly clear sky conditions. Correlations found, even under these screened scenarios, resulted around ~r2 = 0.3. The diurnal responses of SiF, SiF yield, PAM estimates of effective quantum yield (ΔF/Fm′), and meteorological parameters demonstrated some agreement over the diurnal cycle. The challenges inherent in SiF retrievals in boreal evergreen ecosystems are discussed.

Accurately determining the field-of-view (FOV) is a basic requirement in photogrammetry and imaging spectroscopy but has rarely been considered in detail in field spectroscopy where the specifications for different spectroradiometers generally lack clarity or detail. The issue can be further compounded with full spectral systems (0.4 to 2.5µm) which include multiple spectrometers; in these systems the size and alignment of the viewing optics may cause significant spectral non-uniformity across the theoretical measurement area. When recording spectra from heterogeneous targets it is important to have the FOV accurately defined because distinct reflecting surfaces may be present in varying proportions. We assessed the FOVs of the Analytical Spectral Devices Field Spec Pro FR and Spectra Vista Corporation GER 3700 spectroradiometers. The resulting directional response functions are plotted, highlighting several areas of concern.

We present the results from Verification of Reference Irradiance and Radiance Sources Laboratory Calibration Experiment Campaign. Ten international laboratories took part in the measurements. The spectral irradiance comparison included the measurements of the 1000 W tungsten halogen filament lamps in the spectral range of 350 nm–900 nm in the pilot laboratory. The radiance comparison took a form of round robin where each participant in turn received two transfer radiometers and did the radiance calibration in their own laboratory. The transfer radiometers have seven spectral bands covering the wavelength range from 400 nm–700 nm. The irradiance comparison results showed an agreement between all lamps within ±1.5%. The radiance comparison results presented higher than expected discrepancies at the level of ±4%. Additional investigation to determine the causes for these discrepancies identified them as a combination of the size-of-source effect and instrument effective field of view that affected some of the results.

Our research is investigating the relationship between design problem formulation and creative outcome. Towards that goal we have conducted experiments with designers engaged in problem formulation. In order to analyze such empirical data, a formal representation is needed. One popular model is the Function-Behavior-Structure (FBS) model and its several variants. Our problem map (P-map) model shares many common features with FBS but also many differences. A symmetric hierarchical representation is introduced not only in each of the three domains (F, B, S) but in additional domains (requirements and issues). Generic inter and intra-domain relationships between these entities are also identified in addition to optional attributes of the entities, leading to a more expressive and flexible model that is domain independent and well suited for representing problem formulations of designers with different expertise levels and creativity. The model has been used for coding protocol data in a formal predicate logic language (Answer Set Programming).

In field spectroscopy, estimation of the bi-directional reflectance from a target requires paired, near-simultaneous measurement of downwelling irradiance and upwelling target reflected radiance. The conventional approach to field reflectance measurement adopts a single spectroradiometer with single field of view and reflectance panel to take sequential reference (irradiance) and target (radiance) measurements. However, previous research has shown that significant uncertainties in such measurements are introduced with fluctuations in ambient lighting, poorly defined fields-of-view, and known anisotropies of reference reflectance panels.We present a new field spectroradiometer with novel dual field-of-view input optics for repetitive autonomous reflectance measurement across the V-SWIR spectral range (400 to 1700 nm). Attention to the optical design has minimised uncertainties in field reflectance measurement by ensuring a uniform and well defined field-of-view and high accuracy cosine corrected irradiance fore-optic across the full spectral range of the measurement.The system includes just one set of silicon and InGaAs detector array based spectrometers to provide the dual fieldof-view operation, saving on cost, weight and power consumption. An internal microprocessor provides full stand alone control and automation.

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