Simulator and Search Planner for the USCG SAROPS Search And Rescue Optimal Planning System

Transcription

1 Simulator and Search Planner for the USCG SAROPS Search And Rescue Optimal Planning System Metron Inc 1818 Library Street Reston VA

2 SAROPS Background w Developed by Metron, Applied Sciences Associates (ASA), and Northrop Grumman (NG) for the US Coast Guard w Designed to aid Coast Guard Rescue Coordinators in planning and executing searches for people and vessels lost at sea. w Placed in operation March 2007 Replaced Computer Assisted Search Planning system used since 1974 w Three Basic Components GUI (ArcGIS based) developed by ASA and NG Environmental Data Server develop by ASA Gathers environmental data from government and private sources into a server that provides inputs such as winds, currents, and visibility to SAROPS Simulator and Planner developed by Metron Produces probability distributions for search object location and recommends optimal search plans 2

3 SAROPS Display w Typical SAROPS display showing the probability map (distribution) for the search object location and a recommended search plan 3

4 Simulator and Planner w w Metron developed the simulator and planner engine Written in java separable from SAROPS adaptable to many platforms Adapted for Fossett search Description Monte-Carlo based Uses up to10,000 points or particles to represent search object location and type and to produce probability distributions or maps. System can produce and combine multiple scenarios for location and type of search object. Initial (prior) distribution is updated for motion (drift) and unsuccessful search to produce posterior distribution for search planning Detection effectiveness of search sensors modeled by a (lateral range) curve of detection probability as a function of point of closest approach to search object. Curve depends on search object type, search platform, visibility, and sea state (terrain for land searches). 4

5 Simulator and Planner w Description continued Evaluates effectiveness of previous searches Computes cumulative probability of success Tells planner how effective the overall search has been Recommends search plans based on search assets available and the posterior search object location distribution at time of search. Accounts for effectiveness of each sensor/platform and duration of its search Accounts for multiple target types (person in water or life raft) when recommending search plans Estimates probability of success for plan Allows user to modify or recommend a plan provides estimate of success probability for user generated plan. 5

6 SAROPS Interactive Planner Search Plan Recommendation w Planner recommends search areas for three helicopters and estimates 20.2% probability of success 6

7 SAROPS Interactive Planner Evaluation of User Generated Plan w User tries an alternative plan and finds the success probability has dropped to 19.2% 7

8 Use in Fossett Search-1 w SAROPS was used by Metron to form the prior distribution for the crash site of Steve Fossett s aircraft in Multiple scenarios were developed based on data available, knowledge of the area, and Fossett s flying habits hazards such as terrain were represented in SAROPS as higher-likelihood areas for the crash w The search effort was applied to the SAROPS prior to generate a posterior distribution of the crash site: Negative results from forensic radar analysis Negative air, ground, and underwater search results by multiple agencies w The Probability of Search Success (POS) was estimated to be 0.76 w SAROPS was used to recommend areas for further search; POS as a function of additional search hours was generated. 8

9 Use in Fossett Search-2 SAROPS raw output of probability map Flying M Ranch Sodaville sighting Sodaville sighting Rawley #2 sighting Powell Canyon radar Trace LKP Flying M Ranch Probability map overlaid on Google Earth. Rawley #2 sighting Orange areas show the probability that the crash is in that sector. Darker indicates higher probability (overlapping hazards). Powell Canyon radar trace LKP

10 Summary w SAROPS is an operational tool with a proven track record in maritime search and rescue operations w Quantitative predictions of target prior distribution and optimization of search effort allow efficient use of limited search assets. Probability of Success for a search tracks progress and can be used to justify termination search efforts when a threshold is reached. w SAROPS can be modified for application to the inland SAR problem. Fossett search identified several areas where alterations would add fidelity for estimates of target behavior and assessment of search efforts. 10