Contents
Which is MODIS dataset does Earth Engine use?
The MOD14A1 V6 dataset provides daily fire mask composites at 1km resolution derived from the MODIS 4- and 11-micrometer radiances.
Which is MODIS albedo model does Earth Engine use?
The MCD43A3 V6 Albedo Model dataset is a daily 16-day product. It provides both directional hemispherical reflectance (black sky albedo) and bihemispherical reflectance (white sky albedo) for each of the MODIS surface reflectance bands (band 1 through band 7) as well as 3 broad spectrum bands (visible, near infrared, and shortwave).
How to reduce the resolution of Google Earth?
For example, to compute forested area per pixel, use the mean reducer to compute the fraction of a pixel covered, then multiply by area (instead of computing areas in the smaller pixels then adding them up with the sum reducer): // Compute forest area per MODIS pixel.
How does resampling work in Google Earth Engine?
Specifically, when one of these methods is applied to an input image, any required reprojection of the input will be done using the indicated resampling or aggregation method. resample () causes the indicated resampling method ( ‘bilinear’ or ‘bicubic’) to be used at the next reprojection.
How are daily images generated in Earth Engine?
Each 500m/pixel daily image is generated using 16 days of data, centered on the given day. A quality band is also provided for each of the 10 albedo bands. The MCD43A2 V6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Quality dataset is a 500 meter daily 16-day product.
How are pixel values selected in Earth Engine?
For each pixel, a value is selected from all the acquisitions within the 8-day composite on the basis of high observation coverage, low view angle, the absence of clouds or cloud shadow, and aerosol loading.
How is the date of a burn determined in MODIS?
The algorithm identifies the date of burn for the 500m grid cells within each individual MODIS tile. The date is encoded in a single data layer as the ordinal day of the calendar year on which the burn occurred, with values assigned to unburned land pixels and additional special values reserved for missing data and water grid cells.
How is the reflectance of Terra MODIS calculated?
The MOD09A1 V6 product provides an estimate of the surface spectral reflectance of Terra MODIS bands 1-7 at 500m resolution and corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. Along with the seven reflectance bands is a quality layer and four observation bands.
How does the mcd43a1 algorithm work in Earth Engine?
The MCD43A1 algorithm, as is with all combined products, chooses the best representative pixel from a pool that includes all the acquisitions from both the Terra and Aqua sensors from the retrieval period.
How is the reflectance of MODIS data calculated?
The MCD43A4 V6 Nadir Bidirectional Reflectance Distribution Function Adjusted Reflectance (NBAR) product provides 500 meter reflectance data of the MODIS “land” bands 1-7. These are adjusted using a bidirectional reflectance distribution function to model the values as if they were collected from a nadir view.