Michigan Tech Research Institute (MTRI)

Analytical Spectral Devices, Inc. (ASD) FieldSpec3 Spectroradiometer

The FieldSpec3 Spectroradiometer enhances MTRI’s remote sensing field capabilities This instrument accurately measures reflectance, transmittance, radiance, or irradiance in the full spectrum range of 350-2500 nm. It is specifically designed for field environment remote sensing to acquire visible near-infrared (VNIR) and short-wave infrared (SWIR) spectra. Capabilities include both terrestrial and aquatic spectral data collection using three detectors and multiple foreoptic attachments, including one designed specifically for the laboratory environment. In aquatic collections, researchers at MTRI utilize a custom-built gimbal and rod which allows for deployment from boats, bridges, etc.

Pepole on a boat using equipment.
MTRI scientists Zach Raymer, left, and Mike Sayers use the ASD Spectroradiometer to take spectral measurements of algal blooms in Lake Erie.
Wavelength Configuration
VNIR-SWIR1-SWIR2 350–2500 nm
VNIR only  350–1050 nm
WNIR-SWIR1  350–1800 nm
SWIR1 only  1000–1800 nm
SWIR1-SWIR2  1000–2500 nm
SWIR2 only  1800–2500 nm
VNIR and SWIR2  350–1050 nm and 1800–2500 nm
Two people using equipment on a road.
Collection of road surface spectral data
Two people collecting data in a wetland.
Collection of wetland spectral data

Spectral Resolution

  • 3 nm (Full-Width-Half-Maximum) at 700 nm
  • 10 nm (Full-Width-Half-Maximum) at 1400 nm
  • 10 nm (Full-Width-Half-Maximum) at 2100 nm

Sampling Interval

  • 1.4 nm for the spectral region 350-1000 nm
  • 2 nm for the spectral region 1000-2500 nm
Chart of bars and lines.
Road surface profiles used to map road types and surface quality. Shaded bands reflect spectral bands of typical high resolution satellite imagery
Line graph showing a downward trend.
Irradiance measurements taken using aquatic equipment, showing differences in upwelling and downwelling data

MTRI has applied the spectroradiometer to a variety of research projects, including turbidity and trophic state mapping; land cover analysis; the influence of bidirectional reflectance; road surface profiling; crop residue calculations; algal bloom assessment; and forest fire burned-area assessment. We maintain a computing infrastructure to analyze the spectral data, including ENVI and ERDAS Imagine software.

Maps with different colored regions.
Land cover map created with the help of in situ spectral data collects