Subjects and sources are essential components for tracking and monitoring wildlife, vehicles, and other entities. A Subject represents the animal, person, or object being tracked (for more information, see Managing Subjects), while a Source refers to the device that provides data about the subject, such as a GPS collar or tracking unit (for more information, see Managing Sources). 

Administrators manage the relationship between subjects and their sources to ensure accurate tracking and reporting within their EarthRanger system.

Let’s look at an example:

An elephant in a protected area wears a collar that periodically transmits its location to EarthRanger, where the animal's position is recorded and displayed on a map. 

For an EarthRanger administrator:

• The elephant is a Subject with a Subject Type of "Wildlife" and a Subject Subtype of "Elephant."
• The elephant has a Subject Status, which represents its location at a specific time, e.g., 34°N/-1°E, one hour ago.
• The elephant can belong to one or more Subject Groups, such as "Elephants," "Male Elephants," or “Elephants in Virunga.”

The elephant’s collar is a Source. This source has specific characteristics, including:

• Device Model Name (e.g., "AWT")
• Type of Data (e.g., "Tracking Device" or "GPS radio" data)

Finally, administrators can assign a Subject to a Source in the Subject-Source Assignment page, such as linking a specific elephant to a radio collar for a set period of time.

Managing Subject-Source Assignments 

About Subject-Source Assignments 

Associating a subject with a source (e.g., linking an elephant to its radio collar) allows EarthRanger to apply data from the source to the subject.

You assign a source to a subject for a specific period, called the Assigned Range. The Assigned Range is formatted as YYYY-MM-DD HH:MM:SS+HHMM, where HHMM is the time offset from the server's time zone. For example: 2019-08-31 06:21:00+0000.

Managing Subject-Source Assignments:

1. Go to the EarthRanger Administration home page.
2. Select Home > Observations > Subject Source Assignments.
3. This will open the Subject Source Assignments page where the subjects will be displayed as a sortable and filterable list. 

Viewing Subject-Source Assignments 

On the Home > Observations > Subject Source Assignments page, you can:

• Filter and view all subject-source assignments.
• Check if a subject-source assignment is current (i.e., if the current time falls within the Assigned Range).
• Add or delete subject-source assignments. 

Adding a Subject-Source Assignment 

Note: If you need to assign multiple sources to a subject, you can do so by selecting Add Another Source Assignment on the Home > Observations > Subjects > Add Subject page.

To add a subject-source assignment:

1. Go to Home > Observations > Subject-Source Assignment and select Add Subject-Source Assignment.
2. Select a Subject from the menu (Required).
3. Select a Source from the menu (Required).
4. In the Assigned Range section, enter the start and end times of the assignment in the format YYYY-MM-DD HH:MM:SS+HHMM (Required).
5. In the Attributes section, you can add specific information when needed such as:
   • Data Status
   • Data Starts Source
   • Data Stops Source
   • Data Stops Reason
6. In the Advanced section, you can enter additional special settings if needed.
7. Click Save.

List of All Subject Types and Subtypes