Space-time datasets are called differently according to the map type they are formed of: This allows users to perform complex SQL queries using the spatio-temporal extent and metadata information for map selection TGRASS uses an SQL database to store the temporal and spatial extension of STDS, as well as the topological relationships among maps and among STDS.Ī temporal database is a mapset-specific database in which all time stamped maps are registered, i.e.: their spatial and temporal extents, unique ID and A collection of time stamped maps (snapshots) of the same variable are called space-time datasets (STDS) in TGRASS.Įach map in a STDS might have a different spatial and temporal extent. In GRASS GIS words, all pixels in a raster map and all elements in a vector map, It follows a snapshot approach, i.e.: add time stamps toĮxistent maps, to integrate time dimension to the classical spatial GIS. Importantly, the TGRASS concept is based on metadata and does not duplicate any datasets. GRASS GIS is the first Open Source GIS that incorporated capabilities to manage, analyze, process and visualize spatio-temporal data, as well as the temporal The Free and Open Source software ZOO-Project and PyWPSĪllow the user to run GRASS GIS commands in a simple way. It is possible to run GRASS GIS modules through the web using the Web Processing Service R within GRASS GIS console (left) and opening RStudio from GRASS GIS (right) Resolution equal to those of the current computational region, while vector maps are always considered completely. The raster input maps are automatically (on the fly) cropped/padded and rescaled to match the current region, the output maps have their bounds and The computational (or current) region is the actual setting of the region boundaries and the actual raster resolution. GRASS GIS Add-on repository at OSGeo or from Github using the command It is also possible to install further modules, called Add-ons, from a centralized T.rast.aggregate: raster time series aggregation I.pca: Principal Components Analysis on imagery group R.mapcalc: map algebra, r.univar: univariate statistics The graphical user interface offers a tree viewĭ.rast: display raster map, d.vect: display vector map The wealth of modules is organized by their first name in order to easily find the desired functionality. It is possible to analize raster, raster 3D, imagery and vector mapsĪlong with their alphanumerical attributes. GRASS GIS is composed of more than 500 modules to perform any kind of GIS analysis. In a MAPSET you can organize GIS maps thematically, geographically, by project or however you prefer. MAPSETs are subdirectories within Locations. These projects are organized in subdirectories called LOCATIONs.Ī LOCATION is defined by its coordinate system, map projection and geographical boundaries. The GRASS DATABASE (also called "GISDBASE") is an existing directory which contains all GRASS GIS projects. Just a few commonly used terms need to be introduced first. Working with GRASS GIS is not much different from any other GIS. This dataset is required if you cannot download MODIS data from NASA Monthly land surface temperature (LST) from MODIS sensor (MOD11B3.006) for North Carolina (2015-2016).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |