ATP-3-09-30 Observed Fires Download

Adjustment of Fire 28 September 2017 ATP 3-09.30 5-45 TRIGGER AND INTERCEPT POINT CONSIDERATIONS 5-137. Ideally the trigger and intercept points will be an easily identifiable point, terrain feature, or object. This is often difficult to accomplish for targets of opportunity, but for planned targets, the observer frequently has more flexibility in selecting points that will facilitate the execution of the fires. 5-138. However, the observer will often be unable to plan the intercept and trigger point for a planned moving target on easily identifiable objects or terrain features. In these cases, the observer should identify the appropriate point on the ground, then determine and record the direction, distance, and vertical azimuth to the point. This should be done from the point at which the target will be observed during the battle to ensure accuracy. Laser designators and rangefinder are extremely useful for this purpose. Trigger points established in this manner are often referred to as laser triggers, as opposed to physical trigger. TRIGGER POINT MARKING 5-139. If time and conditions permit, the observer may want to mark the trigger points so that they are more visible under various battlefield conditions. While this is especially useful for laser triggers (a laser trigger becomes a physical trigger when marked), it may also be beneficial when the object or terrain feature of a physical trigger may not be easily identifiable under conditions of limited visibility. Often, observers can mark a trigger point together with target area survey and refinement. 5-140. In some instances, the observer may also want to mark the intercept point, especially if direct fire weapons or air assets will jointly attack the target or if planned fires are the backup attack means. The marking of the intercept point allows these systems and other observers to orient on the location and record the data for future use. 5-141. As much as possible, trigger markers should be observable by multiple observers or from multiple locations (in case the observer must move). They should also blend in with the terrain or be placed so that they are not obvious to the adversary. Trigger markers should also be coordinated with the maneuver unit’s direct fire target reference point. All types of trigger markers have limitations that the observer must understand. 5-142. A trigger marker may be visual or thermal. A visual trigger marker, such as a marking panel or chemical light, is clearly visible to normal eyesight (binoculars may be required) under ideal conditions but is affected by night, fog, and other adverse conditions. A thermal trigger (for example, burning charcoal, reverse polarity tape, or a VS-21 panel [the VS-17 panel is normally not visible in thermal sights]) is visible day or night, but may be impacted by dense smoke or fires (burning equipment, munitions, or vegetation) and will only be visible as long as they produce the thermal signature. Use markers that have limited visibility or short durations (and require replacement or replenishment) for marking triggers closer to the observer’s location. 5-143. Reverse polarity tape is difficult to observe beyond 5 kilometers. It is visible through a thermal sight day and night, and adverse weather rarely affects the tape severely. A 5 gallon antifreeze can containing sand and diesel will rarely emit a thermal signature beyond 6 hours. Plywood panels are difficult to conceal from adversary observation. Chemical lights are usually too small to observe from long distances and may be visible to the adversary. Laser triggers minimize the limitations of physical triggers, as they are virtually undetectable to the adversary and require little time to emplace. However, they require a mounted or dismounted observer with a laser designator and rangefinder to maintain a stationary location. If the observer moves, then the established trigger is no longer valid. A combination of laser and physical triggers is the most effective method of establishing trigger points. 5-144. Plan the placement and lighting and initiation of trigger markers such as chemical lights or thermals based on their durations, effects, and other applicable considerations. Plan and assign responsibilities as timeline events. Emplacement can be centralized, with one person, such as the fire support noncommissioned officer (NCO) emplacing all trigger markers, or it may be decentralized, with each observer or platoon responsible for emplacing their assigned trigger markers. There are several methods for emplacing and initiating trigger markers: