Glossary

From Anatrack Ranges User Guide
Jump to: navigation, search

Accuracy ellipses are generated round Locations from bearing data by some packages (e.g. LOCATE II).

Activity centre is calculated as the Arithmetic mean, Recalculated Arithmetic mean or Harmonic mean centre for a set of Locations (a Range).

Arithmetic mean is the mean of x and y coordinates for a Range.

Autocorrelation analysis estimates the degree of spatio-temporal dependence of Locations.

ASCII is American Standard Code, used to turn bytes into text characters.

Bivariate ellipses are based on Location distributions along a major and a minor axis.

Boundary strips round Locations in Polygons have a width of half the Tracking resolution.

Byte arrays are Ranges storage format for Raster maps; each byte codes for 1 raster.

Centroid distance in Cluster analysis is from an Arithmetic mean to all the Locations in a Cluster.

Cluster analysis joins Locations in groups based on the Nearest Neighbour distances between them.

Contour analysis plots Isolines across a Density Matrix to represent either on a probabilistic or Location-inclusive Utilisation distribution.

Core denotes one or more areas of high Location density in a set of Locations.

CSV files are composed of Comma Separated Values (other separators are Break/Space and Tab).

Density Matrix values are estimated at intersections of an arbitrary grid in Contour analyses.

Dispersal detection provides an objective estimate of when animals leave an area.

Dispersion (in contour analyses) the peak density value (at the range centre location) divided by the standard deviation of the density value across all the Locations.

Diversity of areas in Cluster analysis are Simpson's index for the areas within all the cluster Polygons in a Range.

Diversity of locations in Cluster analysis are Simpson's index for the numbers of Locations within all the cluster Hulls in a Range.

Edge denotes an outline estimated round locations as a polygon or by contouring.

Ellipses include circles.

Ellipse asymmetry is the ratio of the standard deviations along the major and minor axes.

End date in a Kaplan Meier Survival analysis is the date to which survival should be estimated; by default the last date for any animal, it may be set earlier to ensure an adequate sample in the last interval or to analyses a particular season; see also Start date.

Focal site denotes an attraction point in a range, such as a den or nest.

ESRI is the Environmental Systems Research Institute, which supplies GIS software.

Grid cells are as wide as the Location resolution.

GIS is a Geographic Information System.

Grid edges are the eastmost, westmost, northmost and southmost coordinates in sets of locations.

Gridascii files are of ASCII values used by ESRI soft for transferring raster map data.

Habitat points are x,y coordinates associated with habitat codes for different trees, etc.

Habitat shapes are formed from a clockwise set of x,y values with the same start and end point.

Harmonic Mean analyses are based on the inverse reciprocal mean of distances to Locations.

Harmonic Mean centre is the Location in a Range at which the inverse reciprocal mean of distances to all other Locations is minimal.

hRef is the reference Smoothing parameter in Kernel analyses ( SD / sixth root N )

Hull is a Polygon with vertices fitted to a set of Locations; a Convex Hull has all external angles greater than 180°.

Incremental analysis estimates and plots the change in Range area as successive Locations are added.

Isolines of equal location density are created during Contour analysis and converted to Polygons.

Jacob's index has values between -1 and +1 to indicate attraction versus avoidance.

Kaplan Meier Survival plots survival in intervals between Start dates and End dates in .srv files and tests for significance between cohorts.

Kernel analyses are based on estimating Location density as functions of distance from all the Locations in a Range.

Kurtosis is an index of spread in the density distribution during Harmonic Mean & Kernel contouring.

Location denotes x,y coordinates of an observation, often with associated qualifying variables.

Location centring is computed during Harmonic Mean contouring to remove Location resolution effects.

Location resolution is the smallest distance that can be recorded between adjacent locations.

Location Qualifying Variables (LQVs) are time, activity, habitat, values associated with x,y coordinates.

Nearest Neighbour distance is the minimum distance between spatially separate Locations.

Neighbour Linkage analyses estimate Polygons round Locations whose individual or summed Nearest Neighbour distances do not exceed a certain value.

Nuclei are the number of separate Polygons defined by Cluster Analaysis.

Objective Cores exclude Locations more isolated than a criterion distance based on the distribution of all Nearest Neighbour distances.

OREP Objective Restrictive Edge Polygons have maximum peripheral edge distances less than a criterion based on the distribution of all Nearest Neighbour distances.

Outlier exclusion distances (OEDs) are derived from the distribution of all Nearest Neighbour distances as either the distance that excludes the outermost 5% of the distribution, or by iterative exclusion of each distances beyond an alpha level until no locations exceed that level.

Outlier locations are those more isolated than a criterion distance based on the distribution of all Nearest Neighbour distances.

Overlap matrices are formed as % overlaps of range A on B and B on A.

Partial area is the summed area of Clusters divided by a single area encompassing all Clusters.

Peeled Polygons are formed as Convex Hulls by excluding Locations furthest from an Activity Centre.

Polygons are formed by lines round a set of vertices, which may be Locations, corners on Vector maps or equal values interpolated on a Density Matrix.

RADA Resource Area Dependence Analysis uses negative correlations of (log) Range Outline area with (log) resource metric (e.g. habitat proportion in the outline) to detect resources that are important enough for animals to expand the area they cover in order to get an adequate supply.

Range is an area defined by analysis of a set of animal Locations observed in a particular period.

Range Core denotes one or more areas of high Location density in a set of Locations.

Range variables are seven values that code ID, age, sex, month, year and focal site coordinates for a Range.

Raster maps are composed of equal-size rectangles with different habitat codes.

Range outline denotes one or more Polygons (including Hulls and Contours) fitted to some or all the Locations in a Range.

Recalculated Arithmetic mean is the mean x and y coordinates, recalculated after each Location of a Peeled Polygon is excluded.

Schoener's index increases from 0 with decreasing spatio-temporal dependence between Locations (= mean squared distances between Locations / mean squared distance from each Location to the Arithmetic mean activity centre).

Shape files are the standard Polygon format in an ESRI GIS.

Skew in the Location density distribution is estimated during Harmonic Mean and Kernel contouring (the Euclidean distance between the Arithmetic mean centre and the Location with the peak density value, divided by the standard deviation of the density value across all the Locations).

Simpson's index increases from 1 with increasing diversity between Polygons in Cluster analysis.

Smoothing factor modulates the density function in Kernel analyses to improve fit of Contours.

Span of a Range is the maximum diagonal dimension of a Convex Hull enclosing all the Locations.

Spread of a Range is the grand mean of distances between all the Locations.

Start date in a Kaplan Meier Survival analysis is the date from which survival should be estimated; by default the first date for any animal, it may be set later to ensure an adequate sample in the first interval or to analyses a particular season; see also End date.

Tracking resolution is the smallest distance that can be recorded between adjacent Locations.

Usual area is the single Polygon that encloses all the separate Cluster Polygons on a Range Core.

Utilisation plots are of Range area against percentages of Location-inclusion or Location-density.

UTM stands for Universal Transverse Mercator and is a two-dimensional Cartesian coordinate system to give locations on the surface of the Earth.

Vector maps are composed of lines and closed shapes defined by a sequence of x,y coordinates.