Visual Summary of sar.lgfl.net Website Content
Objective:
To use probability calculations to determine the chance of
success of a Search and Rescue mission
Probability lesson
SaRprobability.lgfl.net
Job Requirements
Maths required:
•
Calculate percentages
•
Multiply decimals
•
Calculate area
•
Identify sequences
Equipment required:
•
Protractor
•
Ruler
•
Pencil
•
Pen
•
Rubber
Videos
•
Introduction to the Coastguard
•
What challenges does the Coastguard face?
•
Why is Maths so important in Search and Rescue
activities?
Key terms
POC
– Probability of Containment - The probability
of the search object being contained in the
boundaries of some area.
POD
– Probability of Detection - The probability of
detecting the search object.
POS
– Probability of Success - The probability that
the search object will be found.
POS
= POC x POD
Example
A ship has capsized in a fierce storm at night, and
the search and rescue helicopter team has been
called out to assist.
Based on the poor conditions, and the helicopter’s
endurance of 4 hours, the helicopter can only
search an area of 2 square miles.
Based on the conditions, the POC is 60% and the
POD is only 40%.
Calculate the POS (Probability of Success).
POS = POC x POD
= 0.6 x 0.4 = 0.24 = 24%
Example (part 2)
The helicopter could choose to fly a little faster and
cover a larger area. However, this will also reduce its
ability to detect objects.
By flying faster, it can cover an area of 8 square miles
which gives a
POC
of 80%.
But, it’s new
POD
is only 20% as it has less time to
survey each part of the water.
The new
POS = POC x POD
= 0.8 x 0.2 = 0.16 = 16%
In this case, the initial search area had a better
chance of finding the ship.
Determining search areas
The
Coastguard
has to
develop efficient
search techniques.
The speed a helicopter
travels determines its
ability to detect search
objects.
Distance travelled = 48 squares
x 0.5 miles each = 24 miles
1 mile
Area covered ≈ 4 x 4 = 16
miles
2
0.5 miles
POD tables
The following table shows
POD
(Probability of
detection) by a helicopter at various speeds in
various conditions.
This assumes a field of vision of 0.5 miles (as shown
in previous example).
Determining POD
In this example, in clear
conditions we can find
the time taken to
search this area and
the resulting POD.
10mph (100% POD):
24/10 = 2.4 hours
20mph (80% POD):
24/20 = 1.2 hours
40mph (60% POD):
24/40 = 0.6 hours
Distance travelled = 48 squares
x 0.5 miles each = 24 miles
1 mile
Area covered ≈ 4 x 4 = 16
miles
2
Things to consider
•
Why might the helicopter need to search a larger
area?
•
What are the benefits and drawbacks of searching
a smaller area?
•
How could you work out the time taken to cover a
given search area?
A collection of image objects showcasing various slides and visual representations related to sar.lgfl.net. Includes images of different speeds, weather conditions, and specific slides. Each image is described with a title, description, and width information. The content provides a visual overview of the information available on sar.lgfl.net.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
10mph 20mph 40mph Clear conditions 100% 80% 60% Poor conditions 80% 60% 30% Storm conditions 60% 40% 10% sar.lgfl.net
