Transmit or Produce a Rescue Signal

Purpose

The purpose of the beacon would be to signal for help through a visual, auditorial, or signal mechanism and facilitate quicker, more efficient rescue missions.

Design Objective

The overall objective for each of the potential designs is to indicate the current location/status of the module and/or user.

Flares

  • Provide a visual reference to locate the module
  • Self-contained, controlled, brightly burning flame, either stationary or deployed ballistically

Signal lights

  • Provide a sustained visual reference to locate the module
  • Bright LED that either flashes or stays consistently on for a period of time

Sirens

  • Provide a sustained auditory reference to locate the module
  • Air is pushed through a rotating, perforate disk, allowing for a consistent interruption of airflow. This creates rapid changes in air pressure that produces pressure waves and loud sounds (Science Buddies, 2016).

Credit: George Retseck

Radio (or EM) emitters

  • Provide a sustained radio wave signal reference to locate the module
  • Minimal functionality and radius of communication requires only line-of-sight contact with the module (“2-way radio range: How far can two-way radios communicate,” 2020)
  • Radio emitting antenna

GPS pings

  • Intermittent communication with GPS satellites and operators to provide accurate location 
  • Requires communication with satellites to achieve location tracking
  • Provides potential for very long-range signaling

Sonar emitter

  • Consistently sends a sonar signal for use in the water
  • A transducer can send acoustic signals underwater (“What is sonar?,” 2021)
  • Being used solely for transmitting signals, not the usual detection of sounds underwater

Metrics

  • Desired detection radius: 2 miles
  • Intensity of beacon: 70-80 dB (sirens)
  • Window of detection: 2 days

Constraints

  • Minimum signal radius: 100 yards
  • Waterproof
  • Maximum intensity: 85 dB (sustained siren),  110 dB (momentary siren) [5], 4,000 lux (sustained LED) [6]
  • Power requirement: maximum
  • Minimum window of detection: 1 hour

Citations

  1. Retseck, G. (2016). [DIY Disk Siren from household materials] [Image]. Scientific American. https://static.scientificamerican.com/sciam/cache/file/3DD5392C-42FE-4F58-9B3AC82F514138AE_source.jpg?w=590&h=800&7731A373-F3C9-4AE0-A0E638BA76CA6237
  2. Science Buddies. (2016, January 7). Building a disk siren. Scientific American. Retrieved October 13, 2021, from https://www.scientificamerican.com/article/building-a-disk-siren/. 
  3. What is Sonar. (2021, February 26). Retrieved from https://oceanservice.noaa.gov/facts/sonar.html
  4. What is GPS tracking and how does it work? How Do GPS Trackers Work: Vehicle GPS Devices Explained. (2021, June 28). Retrieved October 13, 2021, from https://resources.lytx.com/blog/how-do-gps-trackers-work.
  5. What noises cause hearing loss. (2019, October 7). Retrieved from https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html
  6. Wu, Guangsen, Xiaoyou Huang, He Meng, Le Yang, Shengjian Lin, Yang Gao, Yujun Li, and Yandong Wang. “Retinal Damage after Exposure to White Light Emitting Diode Lights at Different Intensities in Sprague-Dawley Rats.” Annals of Eye Science 4, no. 7 (July 17, 2019): 24–24. https://doi.org/10.21037/aes.2019.06.02.
  7. 2-way radio range: How far can two-way radios communicate. (2020, August 13). Retrieved from https://www.intercomsonline.com/2-way-radio-range-how-far-can-two-way-radios-communicate