Lost Person Behavior (LPB)
Statistical research by search coordinators (Koester, UK SARCat) confirms toddlers (1-3 yrs) rarely travel straight lines; they navigate downhill toward water, lights, or sheltered animal tracks, with 75% found within 1.1 km of the Point Last Seen.
Crucial Rule: Always check water margins, ditches, hedgerows, and vehicle structures first before committing long-range perimeter lines.
Sweep Spacing & POD
Probability of Detection (POD) depends directly on vegetation density and lateral spacing between sweep searchers. In heavy brush, searchers spaced 5 meters apart achieve ~85% POD, while 15m spacing drops detection to below 40% for small targets.
Community volunteers should always have an experienced team leader at each flank to maintain line cohesion.
Safety & Volunteer Briefings
Community search operations require absolute clarity on command radio channels, distress whistlers (3 sharp blasts = emergency/find), medical rally points, and strict preservation of potential footstep evidence or discarded clothing.
Log all sector clearances to prevent duplicating effort while high-probability ground remains unsearched.
Frequently Asked Questions
How does this tool calculate the search rings and sectors?
The planner uses established Lost Person Behavior (LPB) statistical dispersion quartiles (50%, 75%, and 95% dispersion distances) tailored to the subject's mobility category (e.g., toddler, child, vulnerable adult). Radial sectors (Alpha through Hotel) divide the concentric rings into manageable 45-degree search zones that can be assigned to discrete volunteer teams with assigned radio call signs.
What is Probability of Detection (POD)?
POD is the likelihood that searchers will detect a subject if the subject is indeed inside that sector. It is mathematically calculated as POD = 1 - exp(-Coverage), where coverage is determined by sensor/eye sweep width, searcher spacing, and linear distance swept. In dense hedgerows and wooded dykes, spacing must be compressed to maintain acceptable POD.
Can this briefing sheet be exported for print and field radios?
Yes. Clicking "Export Incident Briefing Sheet" generates a standardized, timestamped operational SAR briefing text file complete with LKP coordinates, sector dimensions, sweep spacing protocols, radio assignments, and volunteer safety checklists.