Spatial Joins

a spatial join is similar to

attribute table join

what does a spatial join involve

matching rows from the join features to the target features

what are matching rows in a spatial join based on

their relative spatial locations

what are the results of a spatial join saved in 

a NEW layer 

what must true for both input files in a spatial join

BOTH must be projected

do different data frame projects affect the spatial join

DO NOT

the project from the ______ file is used

destination

target feature vs join features 

target - feature layer that the join WILL ADD the attribute table of the join feature to 

join feature - the feature layer that the attribute table (information) is extracted from

what happens to the geometry of the join features

the original geometry is NOT kept

what are the attributes from the join feature joined to

the attributes of the target features

what is the geometry of the output linked to 

will be the same as the target feature 

what are two join operations

1. join one to one

2. join one to many

what are two join types

keep all

keep common

what is field mapping

controls what attributes fields will be in the output feature class

what are three match options 

intersect 

within a distance 

contains 

what are the two new fields added to the output feature class

1. Join_Count

2. Target_FID

what is Join_Count

field that indicates the number of join features that match each target feature

target_FID means the

target feature

what is the three fields added to the output in a JOIN ONE TO MANY

Join_count

TARGET_FID

JOIN_FID

what can result when the join operation parameter is join one to many 

there can be more than one row in the output feature class for each target feature

what does the join_FID make easier

to determine which feature is joined to which target feature in a join one to many

what does a value of -1 mean for JOIN-FID

means NO feature meets the specified spatial relationship with the target feature

join one to one 

if multiple features are found to have the SAME spatial relationship with a SINGLE target feature = attributes from multiple join features will be grouped 

join one to many

if multiple join feature are found with SAME spatial relationship with SINGLE target features = output will have multiple copies of target feature

when are all input target features ONLY written to the output

the Join operation is set to JOIN ONE TO ONE

AND

keep all target features are checked

what is possible if match option is set to closest or closest geodesic 

two or more join features are at the same distance from the target feature

what happens if two or more join features are at the same distance from the target feature

one of the join features is RANDOMLY selected as the matching feature

what is used to find the 2nd, 3rd or nth closest feature

generate near table

what is important to consider

coordinate system to correctly join features

what are spatial joins based on 

joining attributes of two features based on spatial relationship

point, lines polygons can be spatially joined to

points, lines or polygons

what is the near command

calculates distance to nearest feature

what is the value of a location outside the near command distance 

-1

what does the generate near table tool calculate

the distance and other proximity information between features in one or more feature class/layer

what does the near table generate

a new stand along table

does a near table find only a single near feature

NO - can find more than one feature

what does the extract value to points do

extracts values in raster cells to a point layer

what is the extract value to points tool good for 

good for adding values to your point data (like elevation)

how many layers will the extract by the extract value to points tool

will only extract from ONE raster layer

do you control names with the extract value to points tool

NO - names are the default

contrast extract value to points tool and extract multi values to points

Extract Values to Points - creates a new point feature class containing raster cell values,

Extract Multi Values to Points - appends cell values from one or more rasters directly to the attribute table of an existing point feature class

what values are extracted by the extract multi values to points 

extracts values in raster cells to a point layer 

what is extract multi values to points good for 

adding multiple raster based values to your points 

(ex. elevation, slope. aspect)

can you name layers using extract multi values to points

YES