Change Projection

MoveApps

Github repository: github.com/movestore/change-projection

Description

Change the projection of the movement data.

Documentation

This App transforms the geographical projection of all locations to the requested one.

There are two options:

1. The projection can be provided in a EPGS (e.g.: EPSG:4326), ESRI (e.g.: ESRI:54009) or Proj.4 format (e.g.: +proj=longlat +datum=WGS84 +no_defs +type=crs). The webpages https://epsg.io/ and https://spatialreference.org/ can be of help finding a projection.

2. Tracking data can be projected to a Azimuthal Equidistant (aeqd) projection, in m or km and centering the projection around the center or the centroid of the trajectory. The center is calculated as the midpoint of the range of coordinates of the trajectory. The centroid is the mean point position.

Input data

move2_loc

Output data

move2_loc

Artefacts

none

Settings

Projection: string stating the projection. It can be in a EPGS (e.g.: "EPSG:4326"), ESRI (e.g.: "ESRI:54009") or Proj.4 format (e.g.: "+proj=longlat +datum=WGS84 +no_defs +type=crs").

Azimuthal Equidistant center: the method to identify the coordinates of the center of the trajectory. Options are: center calculates the midpoint of the range of coordinates of the trajectory and centroid calculates the mean point position.

Azimuthal Equidistant units: the units of the Azimuthal Equidistant projection. Options are m or km.

Null or error handling:

Setting Projection: If this all three settings are left empty, a warning is given, the data is not transformed and returned in its original format. If an incorrect CRS code is given, the appropriate error message is given from R and the App stops. If Azimuthal Equidistant center and Azimuthal Equidistant units are provided the Projection setting is ignored.

Settings Azimuthal Equidistant center and Azimuthal Equidistant units: to use the Azimuthal Equidistant projection both of these settings have to be provided (the Projection setting will be ignored). If one is missing, the data is not transformed and returned in its original format.

Data: The output contains the same data as the input but in another projection.