Overview

The Geo-Pointing Module (GPM) is an add-on module for Directed Perception pan-tilt units. It allows applications to point cameras, lasers, and other devices, using Latitude/Longitude coordinates instead of pan-tilt angles. The GPM is a multi-function device that provides:

1. new pan-tilt commands to allow geo-pointing,
2. Ethernet/IP interface for geo-pointing and standard pan-tilt commands, and
3. a set of web pages for graphical configuration and control Geo-coordinates of targets of interest are sent directly to the GPM-equipped Pan-Tilt Unit, and the unit is automatically aimed at that geo-coordinate.

Streams of target coordinates can be sent to the unit allowing tracking/following of targets to keep them in the field-of-view. The Geo-Pointing Module accepts both geo-pointing and standard pan-tilt commands over TCP/IP using the built-in Ethernet port and is compatible with all Directed Perception pan-tilt units. The GPM greatly simplifies system integration and improves system modularity and performance. New GPM-equipped pan-tilt units can be added to the system with little or no change to system logic. Peripheral sensors, such as ground radar, can directly command camera systems to focus on a target of interest. A stream of Geo-positions can be sent to the GPM to track an object of interest. Applications communicate with the GPM over Ethernet (TCP/IP) eliminating the restrictions of serial connections. A built-in web-page interface allows for simple setup and configuration. An interactive landmark-based calibration utility is used to compute the Pan-Tilt's own position. Alternatively, GPS/orientation sensors can be integrated to automate calibration.

System Operation
Commands are accepted over the built-in Ethernet/IP interface to the GPM. The GPM connects to the Pan-tilt unit (PTU) Host Interface (RS-485). Both standard pan-tilt pointing and configuration commands, as well as Geo-pointing commands can be sent to the GPM. Standard pan and tilt commands are passed directly on to the PTU. Geo-pointing commands are processed by the GPM to compute pan-tilt angle commands which are then issued to the attached PTU.

The GPM must be configured with the position of the pan-tilt unit in geo-coordinates (latitude, longitude, altitude, and 3D orientation). The latitude, longitude and altitude of the pan-tilt unit are entered manually using the GPM's web interface (e.g., using a hand-held GPS unit to measure the installed pan-tilt unit position).

The built-in calibration function computes the orientation of the pan-tilt in real-world coordinates using a set of user-provided landmarks. Landmark locations (lat, lon, alt) are entered through the web interface. The pan-tilt is then aimed at four or more landmarks and the system updates the pantilt's position estimate.

Once calibrated, the GPM can accept Geo-pointing commands and queries.

Web Interface
The GPM has a built-in web server and web pages allowing the user to:

• Configure and Control the Pan-Tilt Unit
• Configure and Calibrate Geo-Pointing Module
• Manually Enter Geo-Pointing Commands