[role="xpack"]
[[ingest-geo-grid-processor]]
=== Geo-grid processor
++++
Geo-grid
++++
Converts geo-grid definitions of grid tiles or cells to regular bounding boxes or polygons which describe their shape.
This is useful if there is a need to interact with the tile shapes as spatially indexable fields.
For example the `geotile` field value `"4/8/3"` could be indexed as a string field, but that would not enable
any spatial operations on it.
Instead, convert it to the value
`"POLYGON ((0.0 40.979898069620134, 22.5 40.979898069620134, 22.5 55.77657301866769, 0.0 55.77657301866769, 0.0 40.979898069620134))"`,
which can be indexed as a <> field.
[[geo-grid-processor-options]]
.geo_grid processor options
[options="header"]
|======
| Name | Required | Default | Description
| `field` | yes | - | The field to interpret as a geo-tile. The field format is determined by the `tile_type`.
| `tile_type` | yes | - | Three tile formats are understood: `geohash`, `geotile` and `geohex`.
| `target_field` | no | `field` | The field to assign the polygon shape to, by default `field` is updated in-place.
| `parent_field` | no | - | If specified and a parent tile exists, save that tile address to this field.
| `children_field` | no | - | If specified and children tiles exist, save those tile addresses to this field as an array of strings.
| `non_children_field` | no | - | If specified and intersecting non-child tiles exist, save their addresses to this field as an array of strings.
| `precision_field` | no | - | If specified, save the tile precision (zoom) as an integer to this field.
| `ignore_missing` | no | - | If `true` and `field` does not exist, the processor quietly exits without modifying the document.
| `target_format` | no | "GeoJSON" | Which format to save the generated polygon in. Either `WKT` or `GeoJSON`.
include::common-options.asciidoc[]
|======
To demonstrate the usage of this ingest processor, consider an index called `geocells`
with a mapping for a field `geocell` of type `geo_shape`.
In order to populate that index using `geotile` and `geohex` fields, define
two ingest processors:
[source,console]
--------------------------------------------------
PUT geocells
{
"mappings": {
"properties": {
"geocell": {
"type": "geo_shape"
}
}
}
}
PUT _ingest/pipeline/geotile2shape
{
"description": "translate rectangular z/x/y geotile to bounding box",
"processors": [
{
"geo_grid": {
"field": "geocell",
"tile_type": "geotile"
}
}
]
}
PUT _ingest/pipeline/geohex2shape
{
"description": "translate H3 cell to polygon",
"processors": [
{
"geo_grid": {
"field": "geocell",
"tile_type": "geohex",
"target_format": "wkt"
}
}
]
}
--------------------------------------------------
These two pipelines can be used to index documents into the `geocells` index.
The `geocell` field will be the string version of either a rectangular tile with format `z/x/y` or an H3 cell address,
depending on which ingest processor we use when indexing the document.
The resulting geometry will be represented and indexed as a <> field in either
http://geojson.org[GeoJSON] or the https://docs.opengeospatial.org/is/12-063r5/12-063r5.html[Well-Known Text] format.
==== Example: Rectangular geotile with envelope in GeoJSON
In this example a `geocell` field with a value defined in `z/x/y` format is indexed as a
http://geojson.org[GeoJSON Envelope] since the ingest-processor above was defined with default `target_format`.
[source,console]
--------------------------------------------------
PUT geocells/_doc/1?pipeline=geotile2shape
{
"geocell": "4/8/5"
}
GET geocells/_doc/1
--------------------------------------------------
// TEST[continued]
The response shows how the ingest-processor has replaced the `geocell` field with an indexable `geo_shape`:
[source,console-result]
--------------------------------------------------
{
"_index": "geocells",
"_id": "1",
"_version": 1,
"_seq_no": 0,
"_primary_term": 1,
"found": true,
"_source": {
"geocell": {
"type": "Envelope",
"coordinates": [
[ 0.0, 55.77657301866769 ],
[ 22.5, 40.979898069620134 ]
]
}
}
}
--------------------------------------------------
// TESTRESPONSE[s/"_version": \d+/"_version": $body._version/ s/"_seq_no": \d+/"_seq_no": $body._seq_no/ s/"_primary_term": 1/"_primary_term": $body._primary_term/]
image:images/spatial/geogrid_tile.png[Kibana map with showing the geotile at 4/8/5 and its four child cells]
==== Example: Hexagonal geohex with polygon in WKT format
In this example a `geocell` field with an H3 string address is indexed as a
https://docs.opengeospatial.org/is/12-063r5/12-063r5.html[WKT Polygon], since this ingest processor explicitly
defined the `target_format`.
[source,console]
--------------------------------------------------
PUT geocells/_doc/1?pipeline=geohex2shape
{
"geocell": "811fbffffffffff"
}
GET geocells/_doc/1
--------------------------------------------------
// TEST[continued]
The response shows how the ingest-processor has replaced the `geocell` field with an indexable `geo_shape`:
[source,console-result]
--------------------------------------------------
{
"_index": "geocells",
"_id": "1",
"_version": 1,
"_seq_no": 0,
"_primary_term": 1,
"found": true,
"_source": {
"geocell": "POLYGON ((1.1885095294564962 49.470279179513454, 2.0265689212828875 45.18424864858389, 7.509948452934623 43.786609335802495, 12.6773177459836 46.40695743262768, 12.345747342333198 50.55427505169064, 6.259687012061477 51.964770150370896, 3.6300085578113794 50.610463307239115, 1.1885095294564962 49.470279179513454))"
}
}
--------------------------------------------------
// TESTRESPONSE[s/"_version": \d+/"_version": $body._version/ s/"_seq_no": \d+/"_seq_no": $body._seq_no/ s/"_primary_term": 1/"_primary_term": $body._primary_term/]
image:images/spatial/geogrid_h3.png[Kibana map with showing an H3 cell, and its seven child cells]
==== Example: Enriched tile details
As described in <>,
there are many other fields that can be set, which will enrich the information available.
For example, with H3 tiles there are 7 child tiles, but only the first is fully contained by the parent.
The remaining six are only partially overlapping the parent, and there exist a further six non-child tiles
that overlap the parent.
This can be investigated by adding parent and child additional fields to the ingest-processor:
[source,console]
--------------------------------------------------
PUT _ingest/pipeline/geohex2shape
{
"description": "translate H3 cell to polygon with enriched fields",
"processors": [
{
"geo_grid": {
"description": "Ingest H3 cells like '811fbffffffffff' and create polygons",
"field": "geocell",
"tile_type": "geohex",
"target_format": "wkt",
"target_field": "shape",
"parent_field": "parent",
"children_field": "children",
"non_children_field": "nonChildren",
"precision_field": "precision"
}
}
]
}
--------------------------------------------------
Index the document to see a different result:
[source,console]
--------------------------------------------------
PUT geocells/_doc/1?pipeline=geohex2shape
{
"geocell": "811fbffffffffff"
}
GET geocells/_doc/1
--------------------------------------------------
// TEST[continued]
The response from this index request:
[source,console-result]
--------------------------------------------------
{
"_index": "geocells",
"_id": "1",
"_version": 1,
"_seq_no": 0,
"_primary_term": 1,
"found": true,
"_source": {
"parent": "801ffffffffffff",
"geocell": "811fbffffffffff",
"precision": 1,
"shape": "POLYGON ((1.1885095294564962 49.470279179513454, 2.0265689212828875 45.18424864858389, 7.509948452934623 43.786609335802495, 12.6773177459836 46.40695743262768, 12.345747342333198 50.55427505169064, 6.259687012061477 51.964770150370896, 3.6300085578113794 50.610463307239115, 1.1885095294564962 49.470279179513454))",
"children": [
"821f87fffffffff",
"821f8ffffffffff",
"821f97fffffffff",
"821f9ffffffffff",
"821fa7fffffffff",
"821faffffffffff",
"821fb7fffffffff"
],
"nonChildren": [
"821ea7fffffffff",
"82186ffffffffff",
"82396ffffffffff",
"821f17fffffffff",
"821e37fffffffff",
"82194ffffffffff"
]
}
}
--------------------------------------------------
// TESTRESPONSE[s/"_version": \d+/"_version": $body._version/ s/"_seq_no": \d+/"_seq_no": $body._seq_no/ s/"_primary_term": 1/"_primary_term": $body._primary_term/]
This additional information will then enable, for example, creating a visualization of the H3 cell,
its children and its intersecting non-children cells.
image:images/spatial/geogrid_h3_children.png[Kibana map with three H3 layers: cell, children and intersecting non-children]