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Show HN: Offline SOS signaling+recovery app for disasters/wars

163 points by nizarmah 2y ago

A couple of months ago, I built this app to help identify people stuck under rubble. First responders have awesome tools. But in tough situations, even common folks need to help. After what happened in Myanmar, we need something like this that works properly. It has only been tested in controlled environments. It can also be improved; I know BLE is not _that_ effective under rubble. If you have any feedback or can contribute, don't hold back.

addled 2y ago
Might be rough on battery life, but perhaps pulsing an SOS with the flashlight?
- nizarmah 2y ago
  It is rough, but I like it if it's "toggled" when needed. If the person doesn't respond to an "Are you conscious?" alert, maybe allow responders to "toggle" certain actions like the flashlight you mentioned. A meshnet for communicating back-and-forth between devices. Permissions might be tricky though.
daveguy 2y ago
Okay, what is "disaster detection"? I'd really prefer my phone not chirp noise over Bluetooth channels if I don't notice and respond to a notification in time. Would be nice if the readme included the current method to detect disaster and the nature of the "SOS" signal. Is that something Bluetooth has a behaved protocol for, or is it really just chirping?
- nizarmah 2y ago
  1. Disaster detection is a user toggle-able option that uses motion sensors to detect extreme shifts. 2. SOS signal is a BLE broadcast along with an alarm-like audio (generated from a sine wave). +1, I usually have it off, but toggle it on when I'm in a bad setting. It can be made more accurate with time, especially with onboard ML models. It is a Bluetooth protocol (BLE Scanning and Advertising, if you'd like to learn more about it). I'll be sure to update the readme. Thank you for the great questions!!
  - dylan604 2y ago
    It would be interesting to see if some of the earthquake advanced warning notifications could be integrated too. at least then it would be an "official" warning. seems like false positives would be possible with the device's motion sensors even with an "i'm okay" type of cancel.
    - nizarmah 2y ago
      I LOVE this. Thank you! Huge +1, even though it's not going to be easy. Yeah, false positives are the largest problem. The barometer sensor helps reduce them, but it's not available on all phones. Machine learning can help a lot here, but I haven't looked for publicly available data yet.
  - daveguy 2y ago
    Excellent! Good to know it uses the standard BLE advertisement for the SOS and doesn't need WiFi or GPS. Well thought out. Excellent work. Thank you for making this available as open source! Side note -- I wonder if it's possible to have a companion system to scan regularly for the signal at home for the elderly. Then notify caregivers from the companion using available wifi/cell if the SOS is detected. Since it's so well behaved it seems like even having a regular wellness check mode would be possible. Having a companion system for relay would allow the app itself to never need WiFi/cell and have independent care notifications protocols that wouldn't need to be maintained in the app.
    - nizarmah 2y ago
      Thanks a lot for the kind words! That's a really cool idea. Kudos!! A companion system should be relatively easy. It's also two single devices communicating with each other which makes things much simpler to build as well. This is worth looking closer into.
neuroelectron 2y ago
Do smart phones support "LE Long Range (Coded PHY, S=8)" Perplexity says it can transmit up to a 1km in ideal conditions. Otherwise it's 10-30m indoor.
- nizarmah 2y ago
  Receiving signals doesn't. Advertising likely does. So if someone has proper equipment, they probably can identify the signals. Ideal conditions is likely open spaces with no interference. Walls and concrete lower that as you mentioned. I'm hoping it can help if people are standing right next to the rubble, whether BLE or the "siren" sound. I have no guarantees though. I haven't properly tested because I haven't thought of a low cost option yet.
  - neuroelectron 2y ago
    I'm asking if smart phones support LE Long Range
- nizarmah 2y ago
  Hey neuroelectron! I'm sorry. I misunderstood your question, initially. I don't know if phones support LE Long Range. I will look into it [1]. Thank you!! [1]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5
keyle 2y ago
This is awesome. Technology put to good use. Can voice be transferred? Message be recorded and rebroadcasted? What about making the device vibrate SOS pulses. The person at stake might not have the strength to tap or bang, may be able put the phone on a metallic surface and send vibrations?
- nizarmah 2y ago
  I appreciate it :D Those two questions are spot on. Voice cannot be transferred yet. Re-broadcasting might require a bluetooth meshnet. Vibrations are a great idea. They are not that battery intensive. They also can be detected by 3rd party tech. Both were added to the list of ideas. Thank you!! I haven't done any effort there, because I want to get this into hands.
  - ioleo 2y ago
    Have you considered alternating signals using different radio frequencies? And then use differences in signal arrival times for more accurate location? Also I guess using different bands might be more universal, as signal loss would be different depending on environment and band used.
    - nizarmah 2y ago
      I have not, yet. Right now, it's more of a "signaling life" tool. Improvements are definitely needed with location, but the signal loss as you mentioned is higher priority and restricts what can be used for location. I'm planning to do my homework about alternatives to help mitigate the signal loss. And from there, the options for location might be clearer.
dimal 2y ago
This is great. That said, I think that unless Apple and Google install something like this by default, it won’t get much traction, because you can’t download the app when you really need it, and most people won’t think to download it before then. I just went through Helene in Asheville last year and it was painfully obvious that our cloud overlords have overlooked the offline disaster use case. Basically, when you’re in a situation where you desperately need technology to help, you’re on your own. I was imagining that tools like this would be great, but without the cloud, I was helpless. Maybe instead of trying to get users to install this, it could be a proof of concept to show what’s possible, and to say to Apple and Google: install this basic lifesaving tool on every phone by default?
- nizarmah 2y ago
  This is something I needed to hear for months. Thank you. I'll work towards that. I'll need to figure out how to prove the poc is useful. Apple's "Connect to a Satellite" touches on that, but it's not available for most of the world or on old devices. :|
  - sneak 2y ago
    Starlink is rolling out direct-to-unmodified-cellphone soon, to provide SMS connectivity to devices in locations that would otherwise be completely offline. It will work on standard, unmodified phones (if they are outside and can see the sky). Admittedly doesn’t work under rubble, but should work in the usual/general case.
    - HeatrayEnjoyer 2y ago
      Starlink unfortunately is also not reliable for long-term just outside the US (or even inside).
  - deleted 2y ago
    [deleted]
- thenthenthen 2y ago
  How about pivoting to just infrastructureless short messaging (minus the disaster element). Would this get more people on board? (Disclaimer: I have tried and failed…)
pjs_ 2y ago
This is cool! I have been really enjoying using Meshtastic and LoRa lately. It feels like a blessed relief from the toxic swamp of the regular internet. I love pinging stupid radio messages across the bay without depending on any third-party infrastructure. Maybe in addition to the literal rubble of a life threatening disaster we can use tools like this to dig ourselves out from the psychological rubble of the information superfund site we have built for ourselves
- nizarmah 2y ago
  TIL thanks for sharing those!
- noman-land 2y ago
  You got anyone pinging you back? I can't convince any of my friends to care.
  - genewitch 2y ago
    I'm this way with trying to convince random people on the internet to chat over fldigi on HF frequencies. Hellschriber is awesome.
    - noman-land 2y ago
      TIL! --- Fldigi is a free and open-source program which allows an ordinary computer's sound card to be used as a simple two-way data modem. The software is mostly used by amateur radio operators who connect the microphone and headphone connections of an amateur radio SSB or FM transceiver to the computer's headphone and microphone connections, respectively. This interconnection creates a "sound card defined radio" whose available bandwidth is limited by the sound card's sample rate and the external radio's bandwidth. Such communications are normally done on the shortwave amateur radio bands in modes such as PSK31, MFSK, RTTY, Olivia, and CW. Increasingly, the software is also being used for data on VHF and UHF frequencies using faster modes such as 8-PSK. Using this software, it is possible for amateur radio operators to communicate worldwide while using only a few watts of RF power. https://en.wikipedia.org/wiki/Fldigi https://en.wikipedia.org/wiki/Fldigi
weikju 2y ago
What's not clear to me is, who's listening? Like if I install this app and I get buried under a crumbled building and send out the SOS signal... Are there any receivers???
- nizarmah 2y ago
  People, nearby, with the app installed who open it during a disaster. That's why it needs to be in more hands. Ideally, there would be an option to have your phone "listen" in the background and notify you if anyone needs help. I haven't added that yet. For now: let's say I'm in a neighborhood. An earthquake happens, a building collapses. I have the app installed and I'm fine. So, I open it and I get close to each building and check if there are any survivors under it. You'll keep broadcasting, until your battery runs out. It's not heavy on the battery, so it can broadcast for a while. I'll clarify that in the readme.
  - SlavikCA 2y ago
    Great idea... But appears to be not practical.
    - nizarmah 2y ago
      I agree it's not practical in its current state. The more important problem right now is signaling. Recovery is a much more flexible problem to solve.
      - tough 2y ago
        there was some work on using apple's underlying BLE / mesh network they use for their tracking devices, but with open / alt devices Something like that could be useful if anyone with an iphone going nearby the signal was enough to pick it up, without them requiring to have the app installed.
        nizarmah 2y ago
        This is exactly the goal. It was a little difficult to do, so I just postponed it. TLDR; Apple devices scanning in the background require a lot of workarounds [1]. Another comment suggested proposing this to Apple [2]. If this were built by Apple internally, it would be game-changing. A little delusion never hurt anyone :seenoevil: [1]: http://www.davidgyoungtech.com/2020/05/07/hacking-the-overflow-area http://www.davidgyoungtech.com/2020/05/07/hacking-the-overfl... [2]: https://news.ycombinator.com/item?id=43552544 https://news.ycombinator.com/item?id=43552544
kej 2y ago
I feel like this has some potential overlap with the PulsePoint app (that one is for CPR/AED emergencies rather than large scale disasters), so that could be a potential partnership to look into.
- nizarmah 2y ago
  Thanks! I didn't know about it. They seem pretty mature, but I will reach out to them.
methou 2y ago
There's LoRa runs on 450/900 MHz with complete stack for transmitting and relaying messages. There's even modern encrypted protocol (meshstatic) built on it.
- nizarmah 2y ago
  Another comment mentioned that as well. TIL. I'll look into this before anything else [2]. Cross-platform bluetooth between Android/iOS is too annoying sadly. If LoRa can help address those issues, it would simplify things a lot. [1]: https://news.ycombinator.com/item?id=43552585 https://news.ycombinator.com/item?id=43552585 [2]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5
pizzly 2y ago
Have you considered making the app to take a GPS reading then turn off the GPS to save battery life? If the person say is trapped in rubble they likely not going to move afterwards thus you can relay this location information to nearby receivers.
- nizarmah 2y ago
  This is really smart. I did not! In my situation, GPS was being jammed. That made GPS not useful at all. I tried my best to avoid it for that and battery usage. But this initial reading and turning it off is just genius. I added to the list. Thank you so much!
eddythompson80 2y ago
> It can also be improved; I know BLE is not _that_ effective under rubble. It's a tough problem to solve because you're up against the laws of physics and the very boring (and often counterintuitive) "Antenna Theory". Bluetooth is in the UHF band, and UHF isn't good for penetrating anything let a lone concrete rubble. To penetrate rubble effectively you really want to be in the ELF-VLF bands, (That's what submarines/mining bots/underground seismic sensors use to get signals out). Obviously that's ridiculous. Everything from ELF to even HF is impossible to use in a "under the rubble" situation because of physics[1]. Bluetooth (UHF) might be "better than nothing" but you're losing at least 25-30 dBs (which is like 99.99% signal) in 12 inches of concrete rubble. VHF (like a handheld radio) can buy you another 5 inches. Honestly I think sound waves travel further in such medium than RF waves. [1]: Your "standard reference dipole" antenna needs to be 1/2 or 1/4 your wave length to resonate. At ELF-VLF range you need an antenna that's 10k-1k feet long. You can play with inductors and loops to electrically lengthen your antenna without physically lengthening it, but you're not gonna get that below 500-200 feet. The length of a submarine is an important design consideration when deciding on what type of radio signal it needs to be able to receive/transmit vs how deep it needs to be for stealth.
- pizzly 2y ago
  You could make the phones communicate via sound, not sure how it would impact the battery nor its communication range. Lots of details would have to be worked out. You have to find the frequency that communicates the longest. Perhaps do short pulses of sound to save battery life.
  - genewitch 2y ago
    Unfortunately bass travels the furthest. I can hear cows a lot further away than frogs, and I can hear transport helicopters for miles (miles!) The problem with bass sounds is ostensibly they're nondirectional. So the ideal sound for a phone would probably be the loudest pink noise they can make without blowing the speaker out.
  - trod1234 2y ago
    Problem with sound is it can induce liquefaction in collapsed debris.
tonyhart7 2y ago
this is good but ideally people want this app/platform to be embedded in hardware/OS level
boc 2y ago
Check out the tech behind avalanche beacons for some inspiration. They are meant to locate bodies buried deep in snow debris fields within a meter precision. You have to also have a beacon to search for another beacon.
- eddythompson80 2y ago
  Surprising as it may seem, avalanches are easier to avoid [1] and easier to handle it comes to communication[2]. To an extent of course[3]. [1] I used to be terrified of the concept of an Avalanche. However, at the end of the day you're only exposed to an Avalanche if you choose to be or live next to a large mountain in the winter. It's not even like Hawaiians living next to an active volcano. All you have to do (in terms of living) is to move away during Avalanche season. Hawaiians atleast have the excuse of "it hasn't erupted in 10 years"-maybe. THe other example is if you're a skiing/winter-sport enthusiast (like me). And you simply balance your chance of an avalanche vs the reports and "how much fun it sounds to ski with your friends" [2] If you find yourself in an avalanche situation, you need/must do your best to "swim" to the top of the avalanche. There is gear that can help you do so outside of beacons or "signal based" notifications. Once you've established all those unfeasible, you're left with the same tools a "sudden earthquake victim" is up against. You still have the upper hand because a simple handheld transceiver (from like Icom, Kenwood or Yaesu) will have 100x the range through snow vs one through liquid water or concrete. [3] Physically speaking: ice is eventually going to behave like water under enough depth. I think. [4] Avalanche Gear example: https://alpenglowsports.com/collections/avalanche-safety https://alpenglowsports.com/collections/avalanche-safety
iJohnDoe 2y ago
Kudos for all your hard work! Getting to 1.0, getting on the app store, and making something that should be on all phones - you did awesome! I would change your license so it can’t be stolen by Apple. At the very least they need to buy it or hire you as employee.
- nizarmah 2y ago
  There's a higher chance a person/company can do something valuable with this than Apple buying it or hiring me as an employee. I will also try to create a monetized version for specific use. Maybe that can help fund building a solution that's publicly available. Both of those will increase the chances of it being adopted by smartphones, like Google and Apple. That's why I switched from GPL-3.0 to MIT. I appreciate the kind words and the awesome suggestion. Thank you!
defenestrated 2y ago
This is great. Is there a version of this that does p2p off-grid messaging? Use cases from: 1. Coordination between group members during camping in the wilderness. A mesh solution that works across iOS and Android would be ideal but mesh isn't a hard requirement either. 2. Messaging within a group who's flying together but across different seats/sections at cruising altitude in a long haul flight.
- nizarmah 2y ago
  Not right now. There are applications out there that do p2p off-grid messaging. Some of them might require you open the application the first time ever while on internet. There are many out there (on the App/Play store) that support both use cases you mentioned, I just can't list any off the top of my head because it's been a while since I used one.
np1810 2y ago
Cool idea and this was nostalgic as well... I created a similar application to communicate and send beacon signals over SMS (using Twilio) without Internet (as internet went down) during emergency SoS situation motivated by 2015 Chennai floods... Suggestion: You can possibly try if you can use OpenHaystack [1] to send some "unknown tracker found nearby" alert to any nearby iPhone even if the receiver device doesn't have your app installed or use the FindMy network to send arbitrary data for your app's communication. [2] [1] https://github.com/seemoo-lab/openhaystack https://github.com/seemoo-lab/openhaystack [2] https://github.com/positive-security/send-my https://github.com/positive-security/send-my
improbableinf 2y ago
How many people in my city or neighborhood must install the app (and use it, watch notifications) for it to serve its purpose? It of course depends on the disaster, but in case of war this app can be used to find survivors for purposes other than saving them. Great idea though.
- nizarmah 2y ago
  Every person being rescued must have the app. Only one person rescuing needs to have the app. It'll be easy to find a collapsed building site. The person rescuing just needs to be close to the site with the app. Otherwise, the signal might not be noticed. +1 regarding finding survivors for malicious purposes. I tried my best to lower the surface area of that happening. It's still possible in edge cases, like opposing soldiers finding the people transmitting SOS, but they need to be extremely close to do that.
westurner 2y ago
From "Homemade AI drone software finds people when search and rescue teams can't" https://news.ycombinator.com/item?id=41764486#41775397 https://news.ycombinator.com/item?id=41764486#41775397 : > {Code-and-Response, Call-for-Code}/DroneAid: https://github.com/Code-and-Response/DroneAid https://github.com/Code-and-Response/DroneAid > "DroneAid: A Symbol Language and ML model for indicating needs to drones, planes" (2010) https://github.com/Code-and-Response/DroneAid https://github.com/Code-and-Response/DroneAid > All but one of the DroneAid Symbol Language Symbols are drawn within upward pointing triangles. > Is there a simpler set of QR codes for the ground that could be made with sticks or rocks or things the wind won't bend?
Sakthimm 2y ago
My friend works at one of the world's largest steel plants and recently he was discussing some ideas with me about solving the problem of people disappearing during inspections and being found dead after a few days. Apparently it is a huge problem there that he wanted to build a startup around the tech. I am saying this because I think your target market may not be people stuck under rubble, but large scale industries, construction site workers, miners, firefighters, who can install the app beforehand. Cheers.
- subscribed 2y ago
  I can imagine a firefighter, miner or steelworks worker relying on the smartphone in emergency. Like, seriously, a miner, half of a mile under the rock.... Carrying smartphone? Heavy duty wearable tags and a dense network of wall-mounted relays pinging them and triangulating 24/7 can be the only solution. Sure you can use BLE beacons for that, and this is being solved with multiple competing products as we speak (look up "locating objects in warehouse"), but specifically for the human safety applications, they would have to be imposed by the regulators. Workforce is seen as disposable and nothing short of laws and regulations is going to force employers to improve safety.
  - defrost 2y ago
    The majority of the worlds miners work above ground - they still run the risk of stope (wall) collapse, but they're unlikely to find themselves under half a mile of rock. In Australia, open-cut mining dominates coal production, accounting for over 80% of the total, while underground mining's share has decreased to around 15%. Open-cut mining is generally more efficient and cost-effective, allowing for higher recovery rates and larger-scale operations. and It has been estimated that more than two-thirds of the world’s yearly mineral production is extracted by surface mining. There are several types of surface mining, but the three most common are open-pit mining, strip mining, and quarrying. These differ from one another in the mine geometries created, the techniques used, and the minerals produced. ( https://www.britannica.com/technology/mining/Surface-mining https://www.britannica.com/technology/mining/Surface-mining ) Like anybody else in the modern world, it's hard to pry smart phones away from mine workers ... Miners warned to limit smartphones in the pit (2013) - https://www.itnews.com.au/news/miners-warned-to-limit-smartphones-in-the-pit-329105 https://www.itnews.com.au/news/miners-warned-to-limit-smartp...
simon_acca 2y ago
The EU is mandating Apple to implement WiFi-Direct https://www.ditto.com/blog/cross-platform-p2p-wi-fi-how-the-eu-killed-awdl https://www.ditto.com/blog/cross-platform-p2p-wi-fi-how-the-... WiFi doesn't fare any better than BLE under rubble unfortunately, but WiFi is going to be a useful technology to build disaster response tools in general
- nizarmah 2y ago
  That's awesome. We really need something stable and cross platform. I'm not a fan of how Apple managed to make background BLE advertising and scanning work only with its own devices.
lormayna 2y ago
It would be nice to have a button to play a loud sound. A common use case is to play it when you are under ruin and you hear rescuers close to you. If the rescuers heard a loud sound, they can locate you quicker. I don't know the amount of battery that is necessary to do that.
- nizarmah 2y ago
  The current "Send SOS" plays a loud sound from the speaker, with the SOS beacon. To cut time, I didn't modify the volume programmatically. So the user would need to have their volume set at 100%. This needs improvement, especially considering my phone is always muted. Likewise, the battery usage needs better testing.
DoingIsLearning 2y ago
Not really high tech but worth mentioning that some shortwave portable radios (a world radio receiver is an item you should have in your earthquake emergency supplies) have a portable blare out alarm horn function to signal your presence to first responders. Although it has the obvious limitation that you would have to be within arm's reach of it before you were to be trapped in a collapsing building, and sound can travel sufficiently under rumble.
rapjr9 2y ago
BLE might be useful above ground in some situations, e.g., a person who is unable to stand and is located in a large field of tall grass, or someone who is hiding from an attacker and wants to silently request help. For the specific case of burial under rubble it might be better to work on sensing sounds rather than using radio broadcasts. If the person can move they may be able to tap on concrete with another piece of concrete. Using three or more phones (plus BLE or WiFi for timing coordination) placed on the rubble it might be possible to triangulate the location of the tapping. While there are professional (expensive) versions of this (like the heartbeat detector mentioned above), giving the capability to everyone could be useful. Adding the BLE emission/detection couldn't hurt and when the trapped person runs the app it could give them instructions to maximize their chances of detection. For tapping those instructions might be to tap three times once every five minutes to minimize the physical energy required. That would mean the three sensing phones would need to wait 5 to 10 to 15 minutes to do detection and acquire a location. Tapping on stones could work by itself since people can put their ears to the rubble and listen for the tapping, so the main benefit of the app might be just to tell the person what they should do in their situation (tell the trapped person to tap 3 times every five minutes, tell the rescuer to listen for 3 taps occurring every five minutes, providing a timer to indicate the 5 minute intervals could be useful too). Five minutes might not be optimal, some research would be needed on that, and it may depend on the energy level of the trapped person so perhaps the sensing cell phones should be left in place for hours or days. Ideally all phones would have this as an emergency app that would provide advice and help with BLE beacons, timers, cellular calls, sensing, and whatever in any situation. In general this seems like a difficult problem and worthy of some extended research.
- nizarmah 2y ago
  +1 to sound, I'm planning to research that thanks to all the helpful HN comments like yours :D I find the "instruction app" a little limited because a person needs to be conscious, they need to be calm and collected to remember to open the app, and their phone needs to be accessible. In its current state, providing instructions is better than just broadcasting BLE which will be weakened and lost by rubble. In my country, a lot of first responders still rely on asking people to scream if they can hear them. Anyone unconscious would be discovered days later... There has to be some way of providing an automated signal of life. The comments about the physics limitations are pretty awesome. They make me wonder if we can assist it in any way... I learned about passive resonators recently. I know they have a short distance transmission, but maybe if they were part of the building material? I need to start by learning more about the physics. I know I'm limited by it, but maybe there's window we can walk through instead of the door.
axegon_ 2y ago
There is one thing that could make this insanely valuable. The bad news is that this thing is outside your control: No phone that I know of ships with a LoRa chip. Though to be fair, the only reason why LoRa (and by extension LoRaWAN and Meshtastic) are reliable and robust is precisely because they are not common at all.
INTPenis 2y ago
Satellite based emergency services are already enabled in recent Android phones. I know that only because recently I have been getting a notification on my Pixel 9 Pro that Satellite based emergency services are going in and out of coverage for some reason. I never even knew it existed until my phone told me it was down lol. At this moment they only cover some countries, but it might be well worth focusing on building out this tech instead of trying to make something new.
- nizarmah 2y ago
  It's awesome that it's coming to Android as well. I was mind blown when I got it on my phone traveling between Spain and Portugal by car. It's hard to find a one-size-fits-all solution. I don't know if satellite coverage would still be available under rubble. It's definitely valuable in other situations. The country coverage is a huge part. My country will likely not get satellite coverage in the next 5 to 10 years. Such countries is where disaster response is worse and infrastructure is more prone to failure.
ashoeafoot 2y ago
Silica gel was at the core of a cool water collection contraption to collect moisture in the dessert . Now add this and the ability to sinter sand together in the dessert and you could print windstills with robots.
lunatuna 2y ago
As a thought, not tested, using wifi probe requests might be better through more dense material scenarios. Using a specific AP probe request "SOS Request" from the device would help discover over all the other AP requests that others are throwing. No idea if iOS or Android would let you hijack that process. This is a bit more extreme, but some type of triangulation from multiple rescuers could be useful in closing in on a spot. This is really interesting and thanks for sharing.
- nizarmah 2y ago
  I collected a list of alternative options for signals that I'll be looking into [1]. I included wifi probe requests as well. Thank you so much! [1]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5

163 points by nizarmah 2y ago

addled 2y ago

Might be rough on battery life, but perhaps pulsing an SOS with the flashlight?

nizarmah 2y ago
It is rough, but I like it if it's "toggled" when needed. If the person doesn't respond to an "Are you conscious?" alert, maybe allow responders to "toggle" certain actions like the flashlight you mentioned. A meshnet for communicating back-and-forth between devices. Permissions might be tricky though.

daveguy 2y ago

Okay, what is "disaster detection"? I'd really prefer my phone not chirp noise over Bluetooth channels if I don't notice and respond to a notification in time. Would be nice if the readme included the current method to detect disaster and the nature of the "SOS" signal. Is that something Bluetooth has a behaved protocol for, or is it really just chirping?

nizarmah 2y ago
1. Disaster detection is a user toggle-able option that uses motion sensors to detect extreme shifts. 2. SOS signal is a BLE broadcast along with an alarm-like audio (generated from a sine wave). +1, I usually have it off, but toggle it on when I'm in a bad setting. It can be made more accurate with time, especially with onboard ML models. It is a Bluetooth protocol (BLE Scanning and Advertising, if you'd like to learn more about it). I'll be sure to update the readme. Thank you for the great questions!!
- dylan604 2y ago
  It would be interesting to see if some of the earthquake advanced warning notifications could be integrated too. at least then it would be an "official" warning. seems like false positives would be possible with the device's motion sensors even with an "i'm okay" type of cancel.
  - nizarmah 2y ago
    I LOVE this. Thank you! Huge +1, even though it's not going to be easy. Yeah, false positives are the largest problem. The barometer sensor helps reduce them, but it's not available on all phones. Machine learning can help a lot here, but I haven't looked for publicly available data yet.
- daveguy 2y ago
  Excellent! Good to know it uses the standard BLE advertisement for the SOS and doesn't need WiFi or GPS. Well thought out. Excellent work. Thank you for making this available as open source! Side note -- I wonder if it's possible to have a companion system to scan regularly for the signal at home for the elderly. Then notify caregivers from the companion using available wifi/cell if the SOS is detected. Since it's so well behaved it seems like even having a regular wellness check mode would be possible. Having a companion system for relay would allow the app itself to never need WiFi/cell and have independent care notifications protocols that wouldn't need to be maintained in the app.
  - nizarmah 2y ago
    Thanks a lot for the kind words! That's a really cool idea. Kudos!! A companion system should be relatively easy. It's also two single devices communicating with each other which makes things much simpler to build as well. This is worth looking closer into.

neuroelectron 2y ago

Do smart phones support "LE Long Range (Coded PHY, S=8)" Perplexity says it can transmit up to a 1km in ideal conditions. Otherwise it's 10-30m indoor.

nizarmah 2y ago
Receiving signals doesn't. Advertising likely does. So if someone has proper equipment, they probably can identify the signals. Ideal conditions is likely open spaces with no interference. Walls and concrete lower that as you mentioned. I'm hoping it can help if people are standing right next to the rubble, whether BLE or the "siren" sound. I have no guarantees though. I haven't properly tested because I haven't thought of a low cost option yet.
- neuroelectron 2y ago
  I'm asking if smart phones support LE Long Range
nizarmah 2y ago
Hey neuroelectron! I'm sorry. I misunderstood your question, initially. I don't know if phones support LE Long Range. I will look into it [1]. Thank you!! [1]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5

keyle 2y ago

This is awesome. Technology put to good use. Can voice be transferred? Message be recorded and rebroadcasted? What about making the device vibrate SOS pulses. The person at stake might not have the strength to tap or bang, may be able put the phone on a metallic surface and send vibrations?

nizarmah 2y ago
I appreciate it :D Those two questions are spot on. Voice cannot be transferred yet. Re-broadcasting might require a bluetooth meshnet. Vibrations are a great idea. They are not that battery intensive. They also can be detected by 3rd party tech. Both were added to the list of ideas. Thank you!! I haven't done any effort there, because I want to get this into hands.
- ioleo 2y ago
  Have you considered alternating signals using different radio frequencies? And then use differences in signal arrival times for more accurate location? Also I guess using different bands might be more universal, as signal loss would be different depending on environment and band used.
  - nizarmah 2y ago
    I have not, yet. Right now, it's more of a "signaling life" tool. Improvements are definitely needed with location, but the signal loss as you mentioned is higher priority and restricts what can be used for location. I'm planning to do my homework about alternatives to help mitigate the signal loss. And from there, the options for location might be clearer.

dimal 2y ago

This is great. That said, I think that unless Apple and Google install something like this by default, it won’t get much traction, because you can’t download the app when you really need it, and most people won’t think to download it before then. I just went through Helene in Asheville last year and it was painfully obvious that our cloud overlords have overlooked the offline disaster use case. Basically, when you’re in a situation where you desperately need technology to help, you’re on your own. I was imagining that tools like this would be great, but without the cloud, I was helpless. Maybe instead of trying to get users to install this, it could be a proof of concept to show what’s possible, and to say to Apple and Google: install this basic lifesaving tool on every phone by default?

nizarmah 2y ago
This is something I needed to hear for months. Thank you. I'll work towards that. I'll need to figure out how to prove the poc is useful. Apple's "Connect to a Satellite" touches on that, but it's not available for most of the world or on old devices. :|
- sneak 2y ago
  Starlink is rolling out direct-to-unmodified-cellphone soon, to provide SMS connectivity to devices in locations that would otherwise be completely offline. It will work on standard, unmodified phones (if they are outside and can see the sky). Admittedly doesn’t work under rubble, but should work in the usual/general case.
  - HeatrayEnjoyer 2y ago
    Starlink unfortunately is also not reliable for long-term just outside the US (or even inside).
- deleted 2y ago
  [deleted]
thenthenthen 2y ago
How about pivoting to just infrastructureless short messaging (minus the disaster element). Would this get more people on board? (Disclaimer: I have tried and failed…)

pjs_ 2y ago

This is cool! I have been really enjoying using Meshtastic and LoRa lately. It feels like a blessed relief from the toxic swamp of the regular internet. I love pinging stupid radio messages across the bay without depending on any third-party infrastructure. Maybe in addition to the literal rubble of a life threatening disaster we can use tools like this to dig ourselves out from the psychological rubble of the information superfund site we have built for ourselves

nizarmah 2y ago
TIL thanks for sharing those!
noman-land 2y ago
You got anyone pinging you back? I can't convince any of my friends to care.
- genewitch 2y ago
  I'm this way with trying to convince random people on the internet to chat over fldigi on HF frequencies. Hellschriber is awesome.
  - noman-land 2y ago
    TIL! --- Fldigi is a free and open-source program which allows an ordinary computer's sound card to be used as a simple two-way data modem. The software is mostly used by amateur radio operators who connect the microphone and headphone connections of an amateur radio SSB or FM transceiver to the computer's headphone and microphone connections, respectively. This interconnection creates a "sound card defined radio" whose available bandwidth is limited by the sound card's sample rate and the external radio's bandwidth. Such communications are normally done on the shortwave amateur radio bands in modes such as PSK31, MFSK, RTTY, Olivia, and CW. Increasingly, the software is also being used for data on VHF and UHF frequencies using faster modes such as 8-PSK. Using this software, it is possible for amateur radio operators to communicate worldwide while using only a few watts of RF power. https://en.wikipedia.org/wiki/Fldigi https://en.wikipedia.org/wiki/Fldigi

weikju 2y ago

What's not clear to me is, who's listening? Like if I install this app and I get buried under a crumbled building and send out the SOS signal... Are there any receivers???

nizarmah 2y ago
People, nearby, with the app installed who open it during a disaster. That's why it needs to be in more hands. Ideally, there would be an option to have your phone "listen" in the background and notify you if anyone needs help. I haven't added that yet. For now: let's say I'm in a neighborhood. An earthquake happens, a building collapses. I have the app installed and I'm fine. So, I open it and I get close to each building and check if there are any survivors under it. You'll keep broadcasting, until your battery runs out. It's not heavy on the battery, so it can broadcast for a while. I'll clarify that in the readme.
- SlavikCA 2y ago
  Great idea... But appears to be not practical.
  - nizarmah 2y ago
    I agree it's not practical in its current state. The more important problem right now is signaling. Recovery is a much more flexible problem to solve.
    - tough 2y ago
      there was some work on using apple's underlying BLE / mesh network they use for their tracking devices, but with open / alt devices Something like that could be useful if anyone with an iphone going nearby the signal was enough to pick it up, without them requiring to have the app installed.
      - nizarmah 2y ago
        This is exactly the goal. It was a little difficult to do, so I just postponed it. TLDR; Apple devices scanning in the background require a lot of workarounds [1]. Another comment suggested proposing this to Apple [2]. If this were built by Apple internally, it would be game-changing. A little delusion never hurt anyone :seenoevil: [1]: http://www.davidgyoungtech.com/2020/05/07/hacking-the-overflow-area http://www.davidgyoungtech.com/2020/05/07/hacking-the-overfl... [2]: https://news.ycombinator.com/item?id=43552544 https://news.ycombinator.com/item?id=43552544

kej 2y ago

I feel like this has some potential overlap with the PulsePoint app (that one is for CPR/AED emergencies rather than large scale disasters), so that could be a potential partnership to look into.

nizarmah 2y ago
Thanks! I didn't know about it. They seem pretty mature, but I will reach out to them.

methou 2y ago

There's LoRa runs on 450/900 MHz with complete stack for transmitting and relaying messages. There's even modern encrypted protocol (meshstatic) built on it.

nizarmah 2y ago
Another comment mentioned that as well. TIL. I'll look into this before anything else [2]. Cross-platform bluetooth between Android/iOS is too annoying sadly. If LoRa can help address those issues, it would simplify things a lot. [1]: https://news.ycombinator.com/item?id=43552585 https://news.ycombinator.com/item?id=43552585 [2]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5

pizzly 2y ago

Have you considered making the app to take a GPS reading then turn off the GPS to save battery life? If the person say is trapped in rubble they likely not going to move afterwards thus you can relay this location information to nearby receivers.

nizarmah 2y ago
This is really smart. I did not! In my situation, GPS was being jammed. That made GPS not useful at all. I tried my best to avoid it for that and battery usage. But this initial reading and turning it off is just genius. I added to the list. Thank you so much!

eddythompson80 2y ago

> It can also be improved; I know BLE is not _that_ effective under rubble. It's a tough problem to solve because you're up against the laws of physics and the very boring (and often counterintuitive) "Antenna Theory". Bluetooth is in the UHF band, and UHF isn't good for penetrating anything let a lone concrete rubble. To penetrate rubble effectively you really want to be in the ELF-VLF bands, (That's what submarines/mining bots/underground seismic sensors use to get signals out). Obviously that's ridiculous. Everything from ELF to even HF is impossible to use in a "under the rubble" situation because of physics[1]. Bluetooth (UHF) might be "better than nothing" but you're losing at least 25-30 dBs (which is like 99.99% signal) in 12 inches of concrete rubble. VHF (like a handheld radio) can buy you another 5 inches. Honestly I think sound waves travel further in such medium than RF waves. [1]: Your "standard reference dipole" antenna needs to be 1/2 or 1/4 your wave length to resonate. At ELF-VLF range you need an antenna that's 10k-1k feet long. You can play with inductors and loops to electrically lengthen your antenna without physically lengthening it, but you're not gonna get that below 500-200 feet. The length of a submarine is an important design consideration when deciding on what type of radio signal it needs to be able to receive/transmit vs how deep it needs to be for stealth.

pizzly 2y ago
You could make the phones communicate via sound, not sure how it would impact the battery nor its communication range. Lots of details would have to be worked out. You have to find the frequency that communicates the longest. Perhaps do short pulses of sound to save battery life.
- genewitch 2y ago
  Unfortunately bass travels the furthest. I can hear cows a lot further away than frogs, and I can hear transport helicopters for miles (miles!) The problem with bass sounds is ostensibly they're nondirectional. So the ideal sound for a phone would probably be the loudest pink noise they can make without blowing the speaker out.
- trod1234 2y ago
  Problem with sound is it can induce liquefaction in collapsed debris.

tonyhart7 2y ago

this is good but ideally people want this app/platform to be embedded in hardware/OS level

boc 2y ago

Check out the tech behind avalanche beacons for some inspiration. They are meant to locate bodies buried deep in snow debris fields within a meter precision. You have to also have a beacon to search for another beacon.

eddythompson80 2y ago
Surprising as it may seem, avalanches are easier to avoid [1] and easier to handle it comes to communication[2]. To an extent of course[3]. [1] I used to be terrified of the concept of an Avalanche. However, at the end of the day you're only exposed to an Avalanche if you choose to be or live next to a large mountain in the winter. It's not even like Hawaiians living next to an active volcano. All you have to do (in terms of living) is to move away during Avalanche season. Hawaiians atleast have the excuse of "it hasn't erupted in 10 years"-maybe. THe other example is if you're a skiing/winter-sport enthusiast (like me). And you simply balance your chance of an avalanche vs the reports and "how much fun it sounds to ski with your friends" [2] If you find yourself in an avalanche situation, you need/must do your best to "swim" to the top of the avalanche. There is gear that can help you do so outside of beacons or "signal based" notifications. Once you've established all those unfeasible, you're left with the same tools a "sudden earthquake victim" is up against. You still have the upper hand because a simple handheld transceiver (from like Icom, Kenwood or Yaesu) will have 100x the range through snow vs one through liquid water or concrete. [3] Physically speaking: ice is eventually going to behave like water under enough depth. I think. [4] Avalanche Gear example: https://alpenglowsports.com/collections/avalanche-safety https://alpenglowsports.com/collections/avalanche-safety

iJohnDoe 2y ago

Kudos for all your hard work! Getting to 1.0, getting on the app store, and making something that should be on all phones - you did awesome! I would change your license so it can’t be stolen by Apple. At the very least they need to buy it or hire you as employee.

nizarmah 2y ago
There's a higher chance a person/company can do something valuable with this than Apple buying it or hiring me as an employee. I will also try to create a monetized version for specific use. Maybe that can help fund building a solution that's publicly available. Both of those will increase the chances of it being adopted by smartphones, like Google and Apple. That's why I switched from GPL-3.0 to MIT. I appreciate the kind words and the awesome suggestion. Thank you!

defenestrated 2y ago

This is great. Is there a version of this that does p2p off-grid messaging? Use cases from: 1. Coordination between group members during camping in the wilderness. A mesh solution that works across iOS and Android would be ideal but mesh isn't a hard requirement either. 2. Messaging within a group who's flying together but across different seats/sections at cruising altitude in a long haul flight.

nizarmah 2y ago
Not right now. There are applications out there that do p2p off-grid messaging. Some of them might require you open the application the first time ever while on internet. There are many out there (on the App/Play store) that support both use cases you mentioned, I just can't list any off the top of my head because it's been a while since I used one.

np1810 2y ago

Cool idea and this was nostalgic as well... I created a similar application to communicate and send beacon signals over SMS (using Twilio) without Internet (as internet went down) during emergency SoS situation motivated by 2015 Chennai floods... Suggestion: You can possibly try if you can use OpenHaystack [1] to send some "unknown tracker found nearby" alert to any nearby iPhone even if the receiver device doesn't have your app installed or use the FindMy network to send arbitrary data for your app's communication. [2] [1] https://github.com/seemoo-lab/openhaystack https://github.com/seemoo-lab/openhaystack [2] https://github.com/positive-security/send-my https://github.com/positive-security/send-my

improbableinf 2y ago

How many people in my city or neighborhood must install the app (and use it, watch notifications) for it to serve its purpose? It of course depends on the disaster, but in case of war this app can be used to find survivors for purposes other than saving them. Great idea though.

nizarmah 2y ago
Every person being rescued must have the app. Only one person rescuing needs to have the app. It'll be easy to find a collapsed building site. The person rescuing just needs to be close to the site with the app. Otherwise, the signal might not be noticed. +1 regarding finding survivors for malicious purposes. I tried my best to lower the surface area of that happening. It's still possible in edge cases, like opposing soldiers finding the people transmitting SOS, but they need to be extremely close to do that.

westurner 2y ago

From "Homemade AI drone software finds people when search and rescue teams can't" https://news.ycombinator.com/item?id=41764486#41775397 https://news.ycombinator.com/item?id=41764486#41775397 : > {Code-and-Response, Call-for-Code}/DroneAid: https://github.com/Code-and-Response/DroneAid https://github.com/Code-and-Response/DroneAid > "DroneAid: A Symbol Language and ML model for indicating needs to drones, planes" (2010) https://github.com/Code-and-Response/DroneAid https://github.com/Code-and-Response/DroneAid > All but one of the DroneAid Symbol Language Symbols are drawn within upward pointing triangles. > Is there a simpler set of QR codes for the ground that could be made with sticks or rocks or things the wind won't bend?

Sakthimm 2y ago

My friend works at one of the world's largest steel plants and recently he was discussing some ideas with me about solving the problem of people disappearing during inspections and being found dead after a few days. Apparently it is a huge problem there that he wanted to build a startup around the tech. I am saying this because I think your target market may not be people stuck under rubble, but large scale industries, construction site workers, miners, firefighters, who can install the app beforehand. Cheers.

subscribed 2y ago
I can imagine a firefighter, miner or steelworks worker relying on the smartphone in emergency. Like, seriously, a miner, half of a mile under the rock.... Carrying smartphone? Heavy duty wearable tags and a dense network of wall-mounted relays pinging them and triangulating 24/7 can be the only solution. Sure you can use BLE beacons for that, and this is being solved with multiple competing products as we speak (look up "locating objects in warehouse"), but specifically for the human safety applications, they would have to be imposed by the regulators. Workforce is seen as disposable and nothing short of laws and regulations is going to force employers to improve safety.
- defrost 2y ago
  The majority of the worlds miners work above ground - they still run the risk of stope (wall) collapse, but they're unlikely to find themselves under half a mile of rock. In Australia, open-cut mining dominates coal production, accounting for over 80% of the total, while underground mining's share has decreased to around 15%. Open-cut mining is generally more efficient and cost-effective, allowing for higher recovery rates and larger-scale operations. and It has been estimated that more than two-thirds of the world’s yearly mineral production is extracted by surface mining. There are several types of surface mining, but the three most common are open-pit mining, strip mining, and quarrying. These differ from one another in the mine geometries created, the techniques used, and the minerals produced. ( https://www.britannica.com/technology/mining/Surface-mining https://www.britannica.com/technology/mining/Surface-mining ) Like anybody else in the modern world, it's hard to pry smart phones away from mine workers ... Miners warned to limit smartphones in the pit (2013) - https://www.itnews.com.au/news/miners-warned-to-limit-smartphones-in-the-pit-329105 https://www.itnews.com.au/news/miners-warned-to-limit-smartp...

simon_acca 2y ago

The EU is mandating Apple to implement WiFi-Direct https://www.ditto.com/blog/cross-platform-p2p-wi-fi-how-the-eu-killed-awdl https://www.ditto.com/blog/cross-platform-p2p-wi-fi-how-the-... WiFi doesn't fare any better than BLE under rubble unfortunately, but WiFi is going to be a useful technology to build disaster response tools in general

nizarmah 2y ago
That's awesome. We really need something stable and cross platform. I'm not a fan of how Apple managed to make background BLE advertising and scanning work only with its own devices.

lormayna 2y ago

It would be nice to have a button to play a loud sound. A common use case is to play it when you are under ruin and you hear rescuers close to you. If the rescuers heard a loud sound, they can locate you quicker. I don't know the amount of battery that is necessary to do that.

nizarmah 2y ago
The current "Send SOS" plays a loud sound from the speaker, with the SOS beacon. To cut time, I didn't modify the volume programmatically. So the user would need to have their volume set at 100%. This needs improvement, especially considering my phone is always muted. Likewise, the battery usage needs better testing.

DoingIsLearning 2y ago

Not really high tech but worth mentioning that some shortwave portable radios (a world radio receiver is an item you should have in your earthquake emergency supplies) have a portable blare out alarm horn function to signal your presence to first responders. Although it has the obvious limitation that you would have to be within arm's reach of it before you were to be trapped in a collapsing building, and sound can travel sufficiently under rumble.

rapjr9 2y ago

BLE might be useful above ground in some situations, e.g., a person who is unable to stand and is located in a large field of tall grass, or someone who is hiding from an attacker and wants to silently request help. For the specific case of burial under rubble it might be better to work on sensing sounds rather than using radio broadcasts. If the person can move they may be able to tap on concrete with another piece of concrete. Using three or more phones (plus BLE or WiFi for timing coordination) placed on the rubble it might be possible to triangulate the location of the tapping. While there are professional (expensive) versions of this (like the heartbeat detector mentioned above), giving the capability to everyone could be useful. Adding the BLE emission/detection couldn't hurt and when the trapped person runs the app it could give them instructions to maximize their chances of detection. For tapping those instructions might be to tap three times once every five minutes to minimize the physical energy required. That would mean the three sensing phones would need to wait 5 to 10 to 15 minutes to do detection and acquire a location. Tapping on stones could work by itself since people can put their ears to the rubble and listen for the tapping, so the main benefit of the app might be just to tell the person what they should do in their situation (tell the trapped person to tap 3 times every five minutes, tell the rescuer to listen for 3 taps occurring every five minutes, providing a timer to indicate the 5 minute intervals could be useful too). Five minutes might not be optimal, some research would be needed on that, and it may depend on the energy level of the trapped person so perhaps the sensing cell phones should be left in place for hours or days. Ideally all phones would have this as an emergency app that would provide advice and help with BLE beacons, timers, cellular calls, sensing, and whatever in any situation. In general this seems like a difficult problem and worthy of some extended research.

nizarmah 2y ago
+1 to sound, I'm planning to research that thanks to all the helpful HN comments like yours :D I find the "instruction app" a little limited because a person needs to be conscious, they need to be calm and collected to remember to open the app, and their phone needs to be accessible. In its current state, providing instructions is better than just broadcasting BLE which will be weakened and lost by rubble. In my country, a lot of first responders still rely on asking people to scream if they can hear them. Anyone unconscious would be discovered days later... There has to be some way of providing an automated signal of life. The comments about the physics limitations are pretty awesome. They make me wonder if we can assist it in any way... I learned about passive resonators recently. I know they have a short distance transmission, but maybe if they were part of the building material? I need to start by learning more about the physics. I know I'm limited by it, but maybe there's window we can walk through instead of the door.

axegon_ 2y ago

There is one thing that could make this insanely valuable. The bad news is that this thing is outside your control: No phone that I know of ships with a LoRa chip. Though to be fair, the only reason why LoRa (and by extension LoRaWAN and Meshtastic) are reliable and robust is precisely because they are not common at all.

INTPenis 2y ago

Satellite based emergency services are already enabled in recent Android phones. I know that only because recently I have been getting a notification on my Pixel 9 Pro that Satellite based emergency services are going in and out of coverage for some reason. I never even knew it existed until my phone told me it was down lol. At this moment they only cover some countries, but it might be well worth focusing on building out this tech instead of trying to make something new.

nizarmah 2y ago
It's awesome that it's coming to Android as well. I was mind blown when I got it on my phone traveling between Spain and Portugal by car. It's hard to find a one-size-fits-all solution. I don't know if satellite coverage would still be available under rubble. It's definitely valuable in other situations. The country coverage is a huge part. My country will likely not get satellite coverage in the next 5 to 10 years. Such countries is where disaster response is worse and infrastructure is more prone to failure.

ashoeafoot 2y ago

Silica gel was at the core of a cool water collection contraption to collect moisture in the dessert . Now add this and the ability to sinter sand together in the dessert and you could print windstills with robots.

lunatuna 2y ago

As a thought, not tested, using wifi probe requests might be better through more dense material scenarios. Using a specific AP probe request "SOS Request" from the device would help discover over all the other AP requests that others are throwing. No idea if iOS or Android would let you hijack that process. This is a bit more extreme, but some type of triangulation from multiple rescuers could be useful in closing in on a spot. This is really interesting and thanks for sharing.

nizarmah 2y ago
I collected a list of alternative options for signals that I'll be looking into [1]. I included wifi probe requests as well. Thank you so much! [1]: https://github.com/nizarmah/igatha/issues/5 https://github.com/nizarmah/igatha/issues/5