# How does TerraPop attach area-level data and raster data to microdata?

**URL:** <https://forum.ipums.org/t/how-does-terrapop-attach-area-level-data-and-raster-data-to-microdata/669>\
**Category:** TERRA\
**Created:** [May 12, 2014, 5:29am UTC](https://forum.ipums.org/t/how-does-terrapop-attach-area-level-data-and-raster-data-to-microdata/669 "2014-05-12T05:29:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Terra\_Populus\_Projec](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@Terra\_Populus\_Projec](https://forum.ipums.org/u/Terra_Populus_Projec)\
**Post date:** [May 12, 2014, 5:29am UTC](https://forum.ipums.org/t/how-does-terrapop-attach-area-level-data-and-raster-data-to-microdata/669/1 "2014-05-12T05:29:00Z")

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How does TerraPop attach area-level data and raster data to microdata?

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**Author:** ![Terra\_Populus\_Projec](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@Terra\_Populus\_Projec](https://forum.ipums.org/u/Terra_Populus_Projec)\
**Post date:** [September 4, 2014, 7:14pm UTC](https://forum.ipums.org/t/how-does-terrapop-attach-area-level-data-and-raster-data-to-microdata/669/2 "2014-09-04T19:14:00Z")

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Microdata records include codes identifying the geographic unit within which an individual lives and area-level data include similar codes identifying the unit described by the record. These codes can be used to link microdata and area-level data and connect both types of data to real-world locations through boundary data (shapefiles). To attach contextual variables derived from raster data, the raster data are first summarized to area-level data (see ), and the resulting area-level data are attached to the microdata using the geographic unit codes.