ARPA Target

Introduction

ARPA (automatic radar plotting aid) symbols are small circles colored by default in green: . The ARPA symbols are created and tracked by analyzing the radar picture. ARPA targets can be either computed by the Radar directly or by TimeZero when connected to an Ethernet Radar (when TimeZero receives the radar picture). In this case, TimeZero uses a powerful process to detect, filter and track up to 200 ARPA targets.

Note: When connected to a Furuno FAR or DRS radar via the network, it is possible to choose if the ARPA targets are computed inside the radar antenna (default) or by TimeZero by adjusting the setting "ARPA Processing" available in the Radar Options.

Acquiring ARPA targets

ARPA targets can be manually acquired by:

• Double clicking on a radar echo

• Right Clicking and selecting "Acquire Target"

• Using the "Acquire Target" tool (hidden by default) and left clicking on a radar echo

Note that properly tuning and adjusting your radar for changing conditions (weather, sea state,...) is critical for proper ARPA target tracking. If there is too much noise on the radar picture, this can cause false targets detection. On the other hand, if the radar is not adjusted properly (not enough gain for example), you could miss some targets.

ARPA targets can also be acquired automatically by analyzing Radar Echo inside one or multiple areas. Please refer to the ARPA Auto Acquisition chapter.

ARPA Target Icon

	Just after acquiring a target, TimeZero will process radar data for a few revolutions and display the target using a dashed circle.
	Once the target is fully acquired, TimeZero displays the target using a plain circle with a speed vector (over 1kn).
	Lost ARPA target. This happens if the target becomes out of radar range or if the target cannot be tracked by the radar anymore.
	ARPA Icon (flashing) breaking an alarm condition (either CPA/TCPA or proximity alarm) or ARPA with Hostile classification.

Note: the ARPA target icon size and transparency varies according to its tracking quality. If the radar has difficulties seeing the target, its icon will slowly decrease and its transparency increase until the radar can get a strong echo of the target.

ARPA Color

The default color of all ARPA targets can be changed from the Targets Options. You can also change the color of any ARPA target individually by right clicking on an ARPA target and selecting a color.