User Manual - pancroma

Additional parameters include the RapidEye band number and a graphics imagescale factor. You must scale the reflectance data in order for it to displayproperly since reflectance values are typically between zero and two. In addition,the form has check boxes for writing the TOA reflectance data to file and forrendering it as an image.RapidEye Top of Atmosphere RadiancePANCROMA TM can also compute atmospheric radiance values for RapidEyebands. The procedure is similar to the reflectance calculation. Open a singleinput file and then input the band number. RapidEye radiance values aretypically between 0-1000 so they may have to be scaled to display properly.Click ’OK’ and the band radiances will be computed.Landsat Vegetation IndicesVegetation Indices (VIs) are combinations of DNs or surface reflectances at twoor more wavelengths designed to highlight a particular property of vegetation.Each of the VIs is designed to accentuate a particular vegetation property.Analyzing vegetation using remotely sensed data requires knowledge of thestructure and function of vegetation and its reflectance properties. Thisknowledge enables the linking of vegetative structures and their condition to theirreflectance behavior in an ecological system of interest.The solar-reflected optical spectrum spans a wavelength range of 400 nm to3000 nm. Of this range, the 400 nm to 2500 nm region is routinely measuredusing a variety of optical sensors, including Landsat. Vegetation interacts withsolar radiation differently from other natural materials, such as soils and waterbodies. The absorption and reflection of solar radiation varies depending on thecharacteristics of the vegetation and the incident wavelength. Water, pigments,nitrogen, and carbon are each expressed in the reflected optical spectrum from400 nm to 2500 nm, with often overlapping, but spectrally distinct, reflectancebehaviors. The known signatures allow scientists to combine reflectancemeasurements at different wavelengths to enhance specific vegetationcharacteristics.PANCROMA TM currently provides seven VIs: Vegetation Index (VI), NormalizedDifference Vegetation Index (NDVI), the Modified Soil Adjusted Vegetation Index(msavi2), the Enhanced Green (ENHG) index, the Moisture Stress Index (MSI),Normalized Burn Ratio (NBR) and the Normalized Difference Water Index(NDWI). This reference http://geol.hu/data/online_help/Vegetation_Indices.htmlprovides a good introduction to VIs, as doeshttp://www.yale.edu/ceo/Documentation/rsvegfaq.html.The VI, NDVI, MSAVI2 and ENHG all use the Landsat near infrared (NIR), greenand red bands. The same procedure is used for all three. Open three band files:197