Tracker Type / Modeling Technique

Name: JSS Alpha Beta Tracker

Description: This tracker originally came from documents provided by Rome Air Defense center describing the alpha-beta tracker used at the SOCC to generate airtracks from JSS, FPS-117 and similar radars' returns.

Documentation: None

Source: RADC Documents

Validated: Mitre, 1991

Quality: Started a software in the loop, has been modified since.

Integration capability: Owing to detailed "paint" resolution and accurate rate and format of report this model has been used to drive operator in the loop evaluations. First used in this capability to provide a testbed for alternative air defense workstations at Rome AFB in 1991. Tracker has also been exported to support RAP (Radar Analysis Program) and is used to provide real-time displays from live sensor feed in ANG exercise support.

Name: Angle-Only Alpha-Beta Tracker

Description: This is a variation of the above tracker used to maintain tracks across the focal plane of a sensor. In this case the alpha component (usually the estimated position of the target in 3-space) is the position of the target on the focal plane. The Beta component (usually the estimated target velocity vector) is replaced by the track drift across the focal plane. Candidates for the nearest neighbors confirmation of a track are based upon focal "hot spots" - usually run after filtering techniques (e.g. Hig- and low-pass filters) are run on the raw scene. This is a parametric model, supporting tailoring for specific applications and types of targets tracked. Detections not confirming an active track are maintained in the track database to be correlated into new tracks over time using a linear-fit technique against a user-specified number of frames (e.g. A near-linear fit would be required for x out of y sensor frames, based upon user inputs). The filters and gates for track creation and maintenance are user-definable.

Documentation: None

Source: Unknown

Validated: Martin Marietta Brilliant Eyes Engineers. 1991-2

Quality: Detailed

Integration capability: Used both to track from imported raw and synthetic focal images and also used as a angular track source for testing candidate tracker fusion software.

Name: Parametric Position Alpha-Beta Tracker

Description: This is a variation of the JSS air defense tracker that generates 3D tracks from angular track information from multiple sensors. In addition to the basic aplha-beta tracker capabilities this tracker incorporates a 3D point estimate based upon one or more 2-D tracks. The 3D estimates can be based upon:

Case 1- Reports from multiple sensors available: In this case positional estimates are based upon triangulation from multiple sensor reports and confirming probable multiple detections of a single target in a region (versus viewing different but close targets) by comparing the spectral intensities of each detection at each sensor's focal plane. Extra detections from alternate sensors are used to refine the position estimate of the target if the positions and signatures are "close enough". Otherwise these additional detections are maintained as unconfirmed detections in the track database to be correlated into new tracks over time using a linear-fit technique against a user-specified number of frames (e.g. The user could specify that a near-linear fit would be required for x out of y sensor frames).

Case 2 - Consistent report from one sensor not correlated to other sensors: In this case estimates of the target are based upon it's presumed range from the sensor based upon the signature and the expected threat profile (a database of threat intensities is maintained and checked for this data). The 3D estimate is then based upon the angle and estimated range to the target. This is only used when persistent 2D tracks can not be correlated - the settings for when this are to happen are user-defined.

The filters and gates for track creation and maintenance are user-definable.

Documentation: None

Source: Unknown

Validated: Martin Marietta Brilliant Eyes Engineers. 1991-2

Quality: Detailed

Integration capability: Used in software-in-the-loop tests, but details are unknown.

Name: Multiple Hypothesis Tracker

Description: This is a tracker used for generating 3D tracks from the angle-only tracker reports from multiple sensors described above. While the code still exists, this tracker has not been tested since 1992 and nobody here knows the specifics.

Documentation: None

Source: Unknown

Validated: Martin Marietta Brilliant Eyes Engineers. 1991-2

Quality: Detailed

Integration capability: Used in software-in-the-loop tests, and possibly hardware-in-the-loop test, but details are unknown.

Name: Threat Correlator

Description: This is not a actual tracker, but instead combines the raw detection data with the 3D tracks created through one of the above trackers and makes the estimates the following:

1) The threat type (this was used ONLY for ballistic missiles)

2) Launch Point

3) Impact Point

This algorithm used a database of threat missile profiles including plume data and trajectory profiles in order to generate this information.

Documentation: None

Source: This was a testbed for engineering prototypes

Validated: Martin Marietta Brilliant Eyes Engineers. 1991-2

Quality: Detailed

Integration capability: This module was actually a testbed in its own right and was used to test the feasibility of identifying a target type and trajectory from specific data of limited resolution and accuracy. It was used with feeds from external applications and synthetic images, but the results were always analyzed locally, not dynamically fed to other, integrated elements.