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  1. <!-- meta page description: Temporal data processing in GRASS GIS -->
  2. <!-- meta page index: temporal -->
  3. The temporal enabled GRASS introduces three new datatypes that
  4. are designed to handle time series data:
  5. <ul>
  6. <li> <em>Space time raster datasets</em> (strds) are designed to manage
  7. raster map time series. Modules that process strds have the naming
  8. prefix <em>t.rast</em>.
  9. <li> <em>Space time 3D raster datasets</em> (str3ds) are designed to
  10. manage 3D raster map time series. Modules that process str3ds have the
  11. naming prefix <em>t.rast3d</em>.
  12. <li> <em>Space time vector datasets</em> (stvds) are designed to manage
  13. vector map time series. Modules that process stvds have the naming
  14. prefix <em>t.vect</em>.
  15. </ul>
  16. These new data types can be managed, analyzed and processed with temporal modules that
  17. are based on the GRASS GIS temporal framework.
  18. <h3>Temporal data management in general</h3>
  19. Space time datasets are stored in a temporal database. SQLite3 or
  20. PostgreSQL are supported as SQL database back end.
  21. Connection settings are performed with <a href="t.connect.html">t.connect</a>.
  22. As default a sqlite3 database will be created in the current mapset that
  23. stores all space time datasets and registered time series maps.
  24. <p>
  25. New space time datasets are created in the temporal database with
  26. <a href="t.create.html">t.create</a>. The name of the new dataset, the
  27. type (strds, str3ds, stvds), the title and the description must be
  28. provided for creation. Optional the temporal type (absolute, relative)
  29. and semantic informations can be provided.
  30. <p>
  31. The module <a href="t.remove.html">t.remove</a> will remove the space time datasets
  32. from the temporal database. Use <a href="t.support.html">t.support</a>
  33. to modify the metadata of space time datasets or to update the metadata
  34. that is derived from registered maps. This module also checks for removed
  35. and modified maps and updates the space time datasets accordingly.
  36. Rename a space time dataset with <a href="t.rename.html">t.rename</a>.
  37. <p>
  38. The module <a href="t.register.html">t.register</a> is designed to
  39. register raster, 3D raster and vector maps in the temporal database and
  40. optionally in a space time dataset. It supports different input options. Maps
  41. to register can be provided as a comma separated string at the command line, or
  42. in an input file. The module supports the definition of time stamps
  43. (time instances or intervals) for each map in the input file.
  44. With <a href="t.unregister.html">t.unregister</a> maps can be unregistered
  45. from space time datasets and the temporal database.
  46. <p>
  47. To print informations about space time datasets or registered maps, the
  48. module <a href="t.info.html">t.info</a> can be used.
  49. <a href="t.list.html">t.list</a> will list all space time datasets and
  50. registered maps in the temporal database.
  51. <p>
  52. To compute and check the temporal topology of a space time datasets the
  53. module <a href="t.topology.html">t.topology</a> was designed. The module
  54. <a href="t.sample.html">t.sample</a> samples input space time dataset(s)
  55. with a sample space time dataset and print the result to standard output.
  56. Several different sample methods are supported that can be combined.
  57. <p>
  58. List of general management modules:
  59. <ul>
  60. <li><a href="t.connect.html">t.connect</a></li>
  61. <li><a href="t.create.html">t.create</a></li>
  62. <li><a href="t.rename.html">t.rename</a></li>
  63. <li><a href="t.remove.html">t.remove</a></li>
  64. <li><a href="t.register.html">t.register</a></li>
  65. <li><a href="t.unregister.html">t.unregister</a></li>
  66. <li><a href="t.info.html">t.info</a></li>
  67. <li><a href="t.list.html">t.list</a></li>
  68. <li><a href="t.sample.html">t.sample</a></li>
  69. <li><a href="t.support.html">t.support</a></li>
  70. <li><a href="t.topology.html">t.topology</a></li>
  71. </ul>
  72. <h3>Modules to visualize space time datasets and temporal data</h3>
  73. <ul>
  74. <li><a href="g.gui.animation.html">g.gui.animation</a></li>
  75. <li><a href="g.gui.timeline.html">g.gui.timeline</a></li>
  76. <li><a href="g.gui.mapswipe.html">g.gui.mapswipe</a></li>
  77. <li><a href="g.gui.tplot.html">g.gui.tplot</a></li>
  78. </ul>
  79. <h3>Modules to process space time raster datasets</h3>
  80. The focus of the temporal GIS framework is the processing and analysis of
  81. raster time series. Hence the majority of the temporal modules are designed to process space time raster
  82. datasets. However, there are several modules to process space time 3D raster datasets
  83. and space time vector datasets.
  84. <h4>Querying and map calculation</h4>
  85. Registered maps of a space time raster datasets can be listed using
  86. <a href="t.rast.list.html">t.rast.list</a>. This module supports several
  87. methods how the maps should be listed using SQL queries do determine how
  88. they are selected and sorted. Subsets of space time raster datasets can
  89. be extracted with <a href="t.rast.extract.html">t.rast.extract</a> that
  90. allows additionally to perform mapcalc operations on the selected raster
  91. maps.
  92. <ul>
  93. <li><a href="t.rast.extract.html">t.rast.extract</a></li>
  94. <li><a href="t.rast.gapfill.html">t.rast.gapfill</a></li>
  95. <li><a href="t.rast.mapcalc.html">t.rast.mapcalc</a></li>
  96. <li><a href="t.rast.colors.html">t.rast.colors</a></li>
  97. <li><a href="t.rast.neighbors.html">t.rast.neighbors</a></li>
  98. </ul>
  99. <h4>Aggregation and accumulation analysis</h4>
  100. The temporal framework support the aggregation of space time raster
  101. datasets. It provides three modules to perform aggregation using different
  102. approaches. To aggregate a space time raster map using a temporal
  103. granularity like 4 months, 7 days and so on use
  104. <a href="t.rast.aggregate.html">t.rast.aggregate</a>. The module
  105. <a href="t.rast.aggregate.ds.html">t.rast.aggregate.ds</a> allows the
  106. aggregation of raster map series using the intervals of the maps (raster,
  107. 3D raster and vector) of a 2. space time dataset. A simple interface to
  108. <a href="r.series.html">r.series</a> is the module
  109. <a href="t.rast.series.html">t.rast.series</a> that processes the whole
  110. input space time raster dataset or a subset of it.
  111. <ul>
  112. <li><a href="t.rast.aggregate.html">t.rast.aggregate</a></li>
  113. <li><a href="t.rast.aggregate.ds.html">t.rast.aggregate.ds</a></li>
  114. <li><a href="t.rast.series.html">t.rast.series</a></li>
  115. <li><a href="t.rast.accumulate.html">t.rast.accumulate</a></li>
  116. <li><a href="t.rast.accdetect.html">t.rast.accdetect</a></li>
  117. </ul>
  118. <h4>Export/import conversion</h4>
  119. Space time raster datasets can be exported with <a href="t.rast.export.html">t.rast.export</a>
  120. as compressed tar archive. Such archives can be imported
  121. using <a href="t.rast.import.html">t.rast.import</a>,
  122. <p>
  123. The module <a href="t.rast.to.rast3.html">t.rast.to.rast3</a> converts
  124. space time raster datasets into space time voxel cubes. All 3D raster modules
  125. can be used to process such voxel cubes. This conversion allows the export of space time raster datasets
  126. as netcdf files that include time as one dimension.
  127. <ul>
  128. <li><a href="t.rast.export.html">t.rast.export</a></li>
  129. <li><a href="t.rast.import.html">t.rast.import</a></li>
  130. <li><a href="t.rast.out.vtk.html">t.rast.out.vtk</a></li>
  131. <li><a href="t.rast.to.rast3.html">t.rast.to.rast3</a></li>
  132. <li><a href="r3.out.netcdf.html">r3.out.netcdf</a></li>
  133. </ul>
  134. <h4>Statistics and gap filling</h4>
  135. <ul>
  136. <li><a href="t.rast.gapfill.html">t.rast.gapfill</a></li>
  137. <li><a href="t.rast.univar.html">t.rast.univar</a></li>
  138. </ul>
  139. <h3>Modules to manage, process and analyze STR3DS and STVDS</h3>
  140. Several space time vector dataset modules were developed, to allow the handling
  141. of vector time series data.
  142. <ul>
  143. <li><a href="t.vect.extract.html">t.vect.extract</a></li>
  144. <li><a href="t.vect.import.html">t.vect.import</a></li>
  145. <li><a href="t.vect.export.html">t.vect.export</a></li>
  146. <li><a href="t.vect.observe.strds.html">t.vect.observe.strds</a></li>
  147. <li><a href="t.vect.univar.html">t.vect.univar</a></li>
  148. <li><a href="t.vect.what.strds.html">t.vect.what.strds</a></li>
  149. <li><a href="t.vect.db.select.html">t.vect.db.select</a></li>
  150. </ul>
  151. The space time 3D raster dataset modules are doing exactly the same as their raster
  152. pendants but with 3D raster map layers:
  153. <ul>
  154. <li><a href="t.rast3d.list.html">t.rast3d.list</a></li>
  155. <li><a href="t.rast3d.extract.html">t.rast3d.extract</a></li>
  156. <li><a href="t.rast3d.mapcalc.html">t.rast3d.mapcalc</a></li>
  157. <li><a href="t.rast3d.univar.html">t.rast3d.univar</a></li>
  158. </ul>
  159. <h4>See also</h4>
  160. <ul>
  161. <li>Gebbert, S., Pebesma, E., 2014. TGRASS: A temporal GIS for field based
  162. environmental modeling. Environmental Modelling &amp; Software 53, 1-12.
  163. (<a href="http://dx.doi.org/10.1016/j.envsoft.2013.11.001">DOI</a>)</li>
  164. <li>Vaclav Petras, Anna Petrasova, Helena Mitasova, Markus Neteler, <b>FOSS4G 2014 workshop</b>: <br>
  165. <a href="http://fatra.cnr.ncsu.edu/temporal-grass-workshop/">Spatio-temporal data handling and visualization in GRASS GIS</a></li>
  166. <li><a href="http://www.geostat-course.org/Topic_Gebbert">GeoStat TGRASS Course</a></li>
  167. </ul>