Table 1. Summary of detection data. Figure 6 defines Initial Detection Range. Detection Confidence is a 

 qualitative assessment of the ability of the operator to detect a target within the background clutter and 

 determine whether it is of interest or just surface clutter. 



replay it on a computer. Lockheed Martin is investigating the ability to upload Custom Data 

 Waypoints, but the ability to upload radar-return data docs not exist. 

 Though the radar's shared-sweep capability may optimize surface searching, it could 

 potentially cause interference between surface searches for icebergs and pilots' weather- 

 avoidance needs because the antenna-tilt settings of the weather and surface-search modes are 

 very different. Further investigation is necessary to understand the true impacts. 

 Trivers and Murphy (1993) document a fairly extensive test of the capabilities of the APS- 

 137. Regarding target-identification ability, the APS- 137 is far superior to the APN-241 

 because of its searchlight mode (ISAR operation). The APN-241's target-identification tools 

 are limited and unreliable for target identification. Its target-identification tools include gross- 

 target movement, target shape/return when zoomed, and radar interference/attenuation. 

 As mentioned above, the results documented here are promising and surely point to the need 

 for additional tests and ground-truth experiments. Further experiments should focus on a more 

 realistic target field (ships and icebergs) and more realistic environmental conditions. 

 Additionally, sector searches, as well as more parallel searches, should be used to maximize 

 detection opportunities and detection of targets from various aspect angles. 

 Based on the above 

 findings, the APN-241 is 

 not by itself an adequate 

 sensor for IIP operations. 

 While its ability to detect 

 targets shows some 

 promise, the system lacks 

 a solid target- 

 identification tool or 

 mode. 



Table 2. Summary of position and drift data 



59 



