Decreasing Search Segment Size and Changing Boundaries to Increase POD (coverage) of the Search Area. By Steve McConaughy Member of: Dogs East Inc. The purpose of this discussion is to explore changing the segment size and segment boundaries as a management strategy to optimize area coverage as a search progresses to allow field teams to increase coverage of the search area.. Hypothesis As a missing person search progresses, from initial response to thorough coverage, different field tactics are used. In order for SAR management to best utilize these different field strategies, managers can aid by using different search segment boundaries and making the search areas assigned progressively smaller. Search Stages Though the duration of a typical lost person area search the objectives used to determine how the available resources are deployed changes. These objectives and the whole completion of the search go through several very different personalities. These have been fairly clearly identified and defined by MSO and MLPI texts with only slight variation for several years. Basically those phases of the search are: Type I - Hasty tasks Type II - Full area coverage Type III - Area Elimination Coverage Since one of the most basic precepts of the Incident Command system is that the objectives of the incident lead directly to determining the needed response. IC is a method of management by objectives. Developing objectives from these is a fairly straight forward task. Phase I - Hasty tasks - Objective; Quickly cover highly likely search areas thoroughly enough that if the subject is in the area and obvious he will be detected and prevent the search area from expanding. Phase II - Full area coverage - Objective; Cover the search area thoroughly so that if the subject is in the area and unresponsive or hidden he will be located. Phase III - Area Elimination Coverage - Objective; Thoroughly cover the search area with multiple passes of varied resources so that we can confidently say that the subject is not in this area. Searching in the last several years has made some significant changes in the way we approach our field operations. We have advanced from the tactic of blindly flooding the field with volunteers and line searchers. In the field we are using many new techniques and approaches to more thoroughly cover areas more rapidly with specialized resources. SAR Management has made some significant steps forward in the state of the art. We utilize behavioral statistics and assigning mixed resources to areas providing multiple coverages in areas. We have several options of computers available to determine (to the hundredth of a percentage if we want it) what our cumulative reported POD is for each area searched. If one were to think about the three objectives above it would seem that we would need to employ several relatively drastically different approaches to meeting them. Yet all to frequently, we, as search managers, spend the first hour or maybe more drawing out search crew task assignments on a master map. Using identifiable and obvious man made segment boundaries segmenting out all of the areas in the identified high POA; just as we were taught in all of our SAR management classes. Sometimes we even call in all of the available brain power to develop a Mattson Consensus before assigning the first field teams to be certain we assign the right tasks. As the search progresses, hour after hour - day after day, with no find, very often we find that the same segments are being used, with the same boundaries as were drawn up in that first pressure packed hour on the scene. Drawing the search areas to meet the defined objectives would require a little different approach to segment development. Phase I In the First Phase of the search we can generally assume that the person we are looking for is out there in a likely area to be found, and wants to be found. We can also assume that the teams that we send out are going to be the first trained teams in the area. So, if we get a reasonably clue aware search party within hearing and/or sight of the subject they will locate the person. Deploy Reflex Tasks Keeping this in mind the ideal team would be a fast moving team that could follow the anticipated path the subject was likely to take an check all points where he would have been likely to head to stop. These teams would follow trails, drainages, travel barriers, and check points of attraction. These are sometimes called "Reflex" tasks. At this point in the search the urgency is highest and speed is essential in preventing the search area from continuing to expand. One of the more noted IC's makes it a personal standing objective to deploy at least four initial reflex tasks within 10 minutes of his arriving on scene. These reflex tasks generally require little map study to deploy. An effective way to deploy them is to identify the PLS; Notice all obvious means of travel or travel aids from that point and send a 2-4 person team out along each one. The task assignment would be to: "Cover the drainage (or trail, or fence row, or overlook) as far as is reasonable for this subject to go. Return when you are done." Encompassing this type of task by geographic boundaries actually hinders their completion. Deploy Hasty Tasks Hasty teams are defined as non-thorough area search teams. These can be a number of different resources; Dogs teams, Grid Teams, Sign Cutters etc. These tasks can be deployed while the reflex tasks are in progress. They should generally be designed to cover a lot of area quickly. Grid teams will be widely spaced, dogs will be given large areas and the expected reporting back on thoroughness will be a relatively low POD for each task. Areas assigned to these tasks can be fairly large and may not need to have exactly accurate and definable boundaries on all sides. An elevation contour or a indistinct boundary is probably OK here as this is intended to provide a guide to allow a hasty non-thorough coverage. As per the objective areas defined here they should provide guidance to get teams in the field and quickly cover the likely spots in an area. Phase II In the Second Phase of the search we can assume that if the subject is out there in our segment, he is NOT going to be in the most likely places - Or he would have been found by the Reflex or hasty teams. He may be injured or hidden from view or in a remote or unlikely spot that the first teams would have bypassed. A search would enter this Phase II portion as soon as the initial tasks are completed with no resulting find. Through this phase additional resources will need to be deployed to cover the areas thoroughly. These tasks will generally require accurately defined segments with good boundaries as the areas will need to be thoroughly searched to ensure that there are no gaps between them. These segments should be sized that a thorough search can be made by a trained resource in 4-6 hours. In typical US East Coast conditions this is roughly 150-200 acres. Change the Segment Boundaries. Once the first team completes a thorough search of the area and does not find the subject, if he was in that segment, there was a reason that he was not found. Sending another team to research the area without changing anything, except the time of day, is not likely to greatly increase the chances of finding that person. Mathematically the numbers work out to indicate that many multiple passes of relatively low POD on each pass results in a higher PODcum. Indicating a more thorough coverage. In actuality when resources are reassigned to an area measures are taken to ensure that the team is approaching the task differently what often happens is instead of searching the area more thoroughly the subsequent teams simply recover already thoroughly searched portions of the segment. During this phase multiple coverage of areas is desirable. Multiple passes by different resources (dogs, grid teams, horses etc.) are even better. Information learned in the debriefing should be used to reassign the next teams. Some effort should be made to determine how completely the area was covered (the POC, Probability of Coverage) and reassign areas that were not completed. (New Mexico Search managers seem to be the current leaders in developing methods for doing this). This in effect is re-dividing the search area into smaller areas based on actual field coverages reported. Areas that were not searched thoroughly become their own areas and are reassigned to the next team. The other factor that is often overlooked is that the segment boundaries can be changed. If the previous team was asked to search from creek to creek, redraw the segment to cover from ridge top to ridge top. This will in most cases give the second team a very different perspective on the area to be covered. EXAMPLE: When creeks are used as boundaries many teams will use this as a base line for the initial pass. So if an area is assigned to several teams and all of them cover the creek bed this skews our POD calculations. A disproportionate amount of effort was spent in one area - the creek - and not as much time or search thoroughness would have been spent in the interior segments. This will result in a higher calculated PODcum than actually happened in the field. Phase III In this third Phase of the search we are reaching the wind-down point. Where the probability that the subject is not in our area (ROW becomes higher). The responsible agents need to be beginning to broach to the family that the search is not going to end with a find and investigative efforts in conventional means should be escalating. Decisions on de-escalation of the physical ground search should be beginning to be made. The search objective here becomes one of proving that the subject is not in the areas that are being covered. This requires a much finer grid and more attention to detail as these teams are obviously not the first ones in an area and will in most cases be the last search resource deployed to the area. These teams need to be able to come back and on debrief report that they are certain the subject is not in the searched area. These should be yielding relatively high POD's. This also assumes that the subject may not be responsive - or they would have very likely been located in the phase II search efforts. How do we as IC's and search managers, standing at base, increase the coverage of an area in the field? Additional training of teams will increase the POD it but this is a long term project, not one that can be done on the search scene. The availability of resources is generally fixed. We call for what we think we need, hope it is available and use what we get. At base, as search managers, we have only three things within our control that can significantly affect the thoroughness that the teams we are assigning can do their jobs: 1- We can control the time that we a lot to complete a task in. 2 - We select appropriate units available on the scene to deploy to each area. 3 - We have control over the boundaries of the assigned areas (and thus also the size of the areas). We can control the time that we give to complete a task. Somewhat.... Some factors to consider here: Each task reassignment involves some additional overhead time. This is downtime for the team and requires additional base staffing. This overhead time increases when transportation is required and increases proportional to distance from base or redeployment increases. My observation is that each time a team returns to base it takes at least an hour (plus transport time) to get them back in the field. This is regardless of the length of time they have been in the field. This includes time to get back take their packs off, get a drink and maybe a candy bar, crate or tie up the dog check in with Ops., debrief be reassigned a new area and map, reassemble the team, gear up, find transportation to the new area. Obviously small teams in efficiently manned search bases can do this faster than larger teams in larger searches so if we give a short task i.e. ask them to be through in 1 hour. They will have +/- 1 hour turn around in base. This results in a 50% overhead loss. If they are in the field 2 hours then a 1 hour base turn around to the new segment they have a 33% overhead loss. After about 4-5 hours in the field the administrative reassignment seems to be longer as teams feel the need to eat something and take a break to refresh themselves or their dogs. The time in base tends to increase but the overhead loss ratio stays about the same as they are working in the field longer. From the chart above. It seems obvious that having teams return to base in less than 3 hours creates a significant loss and additional non productive overhead administrative burden. To lessen this impact, reassignments may be done in the field over the radio which can eliminate the transportation time, and base delay, especially if the new search area is close to or adjoining the current one. Search areas can also be assigned ahead of time. "I want you do clear area A - When you are one go to area B." An additional factor in extending time in the field is the effectiveness of the teams. Field research has demonstrated that the observation powers and ability to detect clues begins to drop after about 5 hours. Maintaining searcher safety also becomes an issue in long tasks. SO there is a point where long assignments become less productive because of fatigue and boredom of the team. This time of diminishing effectiveness varies from team to team. It is generally probably shorter for newer or less trained and less physically fit teams and longer for more experienced and well adjusted and equipped veterans. Therefore it appears that tasks that take someplace between 4 and 6 hours are the most productive and require the least overhead cost. So as search managers we can alter the time we assign teams to tasks but are limited by physical limitations of the searchers and the logistics in the gain that we get out of doing so. We have our choice of units on the scene to deploy to each area. We should assign a mixture of teams to an area. Each team will cover the same area with slightly different techniques and emphasis. But in most cases, once 2-3 different resource types are deployed we are forced to repeat coverage again. There simply are generally not additional new types of resources available. We can alter the size of the assigned areas: In order to do a fine search with sufficient detail to find a subject that has already been missed by multiple passes the attention to detail and clue awareness has to be increased. The line spacing of grid teams needs to be shortened and the sweeps of dog teams made shorter. If we assume that the effective search time for a team still remains about the same of 4-6 hours in the field, then the only realistic option to cover this area more thoroughly is to divide the high POA areas into smaller search areas and cover them thoroughly. A look at law enforcement evidence searches or cadaver dog tasks are two examples of this. In both of those types of searches small areas are parceled out and marked clearly with boundaries and each small area is cleared systematically and thoroughly before going on to the next. Another aspect of smaller segments late in the search is the psychological impact on the teams. On day 4 of a search, where teams know that any area assigned has already been covered several times if the IC asks them to search a 300 acre segment to a 80% POD. There is an almost universal initial feeling of futility from the team - like searching for the needle in the haystack. If that same team were given a 30 acre segment that would not be as devastating as it is still a reasonable area (a much smaller haystack) to thoroughly search. HOW can we accomplish this? - Techniques We have listed some of the advantages of reducing segment size as the search progresses. On a practical basis, How do we do this? Reassignment from Base - The easiest way to manage this is simply to have the management assign smaller areas, using different boundaries on each subsequent shift or recoverage of an area. Unfortunately the logistics of this often make it rare that this actually happens. Subdividing Areas - Some areas are already using procedures that effectively allow subdividing to happen. One of the benefits of the Percentage of Coverage (POC) technique that has been used effectively in New Mexico helps identify areas covered and areas that were assigned but not covered. Once these are identified they can be reassigned to additional teams or to other resources. Segment Division in the Field - Teams that are assigned areas larger than can reasonably be searched at one time have the option of sub dividing segments. These divisions can then be searched thoroughly one at a time one after the other. They can also be made available to other teams that may have come available either by completing their segments or new resources reporting in. Multiple Team Assignment - Assigning two resources simultaneously to a high POA area that has already been covered can work. The two team leaders should work together to develop a strategy between them that both are comfortable with. Working the Numbers - One of the main points of resistance to redividing areas is that it makes the math for determining the coverage of areas (PODcum) more difficult. There are currently several very sophisticated software programs available that can assist with this. Unfortunately most are unable to deal with different segment size or boundaries. Once a segment is entered into a computer it stays that way throughout the search!! This could be cited as a case of the computer capabilities directly influencing and affecting the coverage achieved in the field! The optimum solution would be a graphically based computer program where a manager could trace on the screen the outline of the each area as it is covered. The computer program would looks at each segment and define the area by pixels and give a value to each pixel included in that area. If there are more than one passes over any pixel it would determine a cumulative coverage for each one. This would allow for any size or shape of segment to be assigned based on field need and not on software capability. So far there is no program of this nature available. We can though allow more accurate definition of the field results by identifying the smaller segments. If there is an uneven overlap between two task assignments the redividing the overlap area into another segment can portray accurately the appropriate coverage. The figure above demonstrates how 2 search tasks can be overlaid on each other to produce a third area. This area may is to be used not as a field assignment but to reflect the PODcum of the tasks completed. If we have reports from the field that the POD coverage achieved was 50% in segment A and 50% in segment B then the PODcum in segment C would be 75%. Using the standard PODcum formula: (PODcum =1-[(1-POD1)x(1-POD2)]. Subsequent field tasks may be overlaid and additional PODcum figures determined for additional areas of multiple coverage. CONCLUSION In conclusion one of the main tasks of the managers and planners assigning tasks to field teams, is to present them with field assignments that lead them to cover the areas to the desired POD for the search. As a search progresses from initial response on through final coverages, making the areas assigned smaller allows for better coverage of each area. Altering the boundaries of the segments creates a different look and feel to the search area for the searcher and often leads to different approaches or field tactics to be used. This results in the same ground area being covered with a different emphasis that may allow it to be searched with different results. Decreasing Search Segment Size and Changing Boundaries to Increase POD (coverage) of the search area. By Steve McConaughy Member of: Dogs East Inc.Hypothesis As a missing person search progresses different field tactics are used. In order for SAR management to best utilize these strategies, managers can aid best by: 1. using different search segment boundaries. 2. making the search areas assigned progressively smaller. Phases of a Search Phase I - Hasty & Reflex tasks: Search wide areas so that an obvious subject in the area will be detected. Quick deployment. Cover highly likely search areas in the segments. Prevent the search area from expanding. Phase II - Full area coverage: Search to locate the unresponsive or hidden subject. Interior area search - requires defined boundaries. Grid or thorough methods used. Search Phase III - Area Elimination Coverage: Cover the search area to confidently say that the subject is NOT in this area. Detail Searching - Cover all areas that may have been missed. Phase I Person we are looking for is out there in a likely area to be found, and wants to be found. Assigned teams are the teams first-deployed resource. Teams assigned within hearing and/or sight of the subject will locate the person. Search Tactics Used: Deploy Reflex tasks. Deploy Hasty Tasks. Hasty teams are defined as non-thorough area search teams. Areas assigned to these tasks can be fairly large and may not need to have exactly accurate and definable boundaries on all sides. Phase II A search would enter this Phase II portion as soon as the initial tasks are completed with no resulting find. After the first team completes a thorough search of the area and does not find the subject, there was a reason that he was not found if he was in that segment. If the subject is out there, he is NOT going to be in the most obvious likely places - or He may be.. - injured or hidden from view or in a remote or - in an unlikely spot that the first teams may have bypassed. Requires : Accurately defined segments with good boundaries. Segments should be sized to last 4-6 hours. Change the segment boundaries OFTEN! Mix the resource assignments (Dogs-Ground Sweep, Horse). Reassignment of sectors: Determine how completely the area was covered (the POC). Reassign areas that were not completed. (eg. New Mexico). Redividing the search area into smaller tasks. Change the segment boundaries. Gives the second team a very different perspective on the area to be covered. Reduces chance of boundary miss. EXAMPLE: Alternate creek and road - Creek and Ridge as boundaries. Phase III The search objective here becomes one of proving that the subject is NOT in the areas that are being covered. This requires: A much finer grid and more attention to detail. Role of IC's and Search Managers Search Managers, we have only three things within our immediate control: 1- We can control the time allowed to complete a task. 2 - We select appropriate units to deploy to each area. 3 - We have control over the boundaries of the assigned areas (and thus also the size of the areas) Alter the size of the assigned areas. Alter the boundaries used to assign areas. TIME to complete tasks Each reassignment involves some additional overhead time. My observation - - Each time a team returns to base it takes at least an hour (plus transport time) to get them back in the field. After 4-6 hours in the field efficiency of teams drops. Cutting overhead (reassignment) time loss. Reassignments may be done over the radio. Assign back up Search areas can also be assigned ahead of time. Choice of units: Assign a mixture of teams. Each team will cover the same area with slightly differently. Limited to units on the scene. Requires familiarity to make appropriate assignments. Relative team efficiency related to length of field tasks. Alter the size of the assigned areas. Smaller search areas can be covered more thoroughly. eg: Evidence search. Cadaver search. Article Search. Clue finders. Psychological impact on the teams. Feeling of futility from the team. Searching for the needle in the haystack. Make small Haystacks. Alter Boundaries of the assigned areas: Rewalking, a strategy already covered, does NOT significantly increase the POD! However.. Boundary misses can be caught. Additional routes of travel and/features may be noticed. Covering holes and uncovered areas does presents a different "Search puzzle" for the field team assigned. Techniques: Reassignment from Base: Segment division in the field. Ask for help ! Divide your job. POC Determination: Assign multiple teams jointly to one area. Working the Numbers: . . . Pixel based computer program optimum - not currently available Standard PODcum formula:(PODcum =1-[(1-POD1)x(1-POD2) (1-PODx)]. Statistical Segments. CONCLUSION As a search progresses from initial response on through final coverages: - Making the areas assigned smaller allows for better coverage of each area. - Altering the boundaries of the segments creates a different look and feel to the search area for the searcher and often leads to different field tactics to be used. This can result in the same ground area being covered with a different emphasis that may allow it to be searched with different results. --- End --- Steve McConaughy Search Equipment Company. Providing quality equipment for Search Teams everywhere. P.O. Box 70626, Richmond, Virginia, 23255 Phone:(804)967-9264 FAX:(804)967-9265 E-mail: SAR_Equip@compuserve.com Web Site: http://ourworld.compuserve.com/homepages/SAR_Equip 05/28/97 ---------------------------