Which of the following is NOT a characteristic of indirect radar echoes?

Indirect radar echoes are a phenomenon that occurs in radar tracking and interpretation, particularly concerning the nature of the targeted objects and environment. The characteristic that indicates they always appear on a bearing of 90° from the true bearing of the contact is not accurate. This implies a fixed relationship between the contact's direction and the radar’s reading, which contradicts the nature of indirect radar echoes. These echoes may display erratic or varied bearings influenced by factors such as the radar's position, specific environmental conditions, and the nature of the radar reflections.

Other characteristics, such as abnormal movement when plotted, their appearance in shadow sectors where radar signals may be blocked or influenced, and the tendency to maintain a constant bearing even when the true bearing of the contact varies, demonstrate the complexity and peculiarity of indirect echoes. Instead of adhering to a strict geometric relationship with the original contact, indirect radar echoes can lead to misinterpretations, making the understanding of their characteristics essential for effective radar operation and navigation.