9 ms·

Show HN: Find3 – An indoor positioning system for smartphones and laptops

265 points by qrv3w 9y ago

llao 9y ago
The byline says "High-precision" but I could not find any benchmarks or scientific analysis. What does high precision mean here? How stable is it? What about privacy of the users? Does the server know where everyone is?
- consultutah 9y ago
  Yep. Needs to answer what is the precision?
- qrv3w 9y ago
  The actual precision you get depends on context, as this system utilizes surrounding signals (Bluetooth/WiFi/etc.) in the given environment to classify the location. Generally rooms/walkways are easily distinguishable. Pieces of rooms are also usually distinguishable because of smart devices people generally acquire nowadays (e.g. a Google home at one side of the kitchen is sufficient). I say high-precision because I compare it to GPS, but if you compare it to round-trip time (RTT) measurements which get cm-level precision from specialized hardware, it is an order-of-magnitude behind. The public server knows the mac addresses of devices that they send to it, so in a sense it does know where they are (because those can be reversed with public wardriving databases). The public server does not have authentication, so if someone figures out your "family name" then they can see your data. I suggest using the public server to try FIND, but not to use FIND so I have instructions for setting up your own system. [1] I'll make this more clear in the docs. [1] https://www.internalpositioning.com/doc/server_setup.md https://www.internalpositioning.com/doc/server_setup.md
coupdejarnac 9y ago
Haven't read through the code yet, but the only thing I need to know is if these guys know what Rayleigh scattering is. If not, this probably isn't going to work so great. I worked on an indoor tracking system several years ago that used custom hardware. Since then, I've seen a lot of crappy solutions that use BLE RSSI measurements. This is simply not an easy problem to solve with crude methods.
- mlevental 9y ago
  they're fingerprinting locations based on rssi from devices in the signal environment. meaning your phone tries to connect, gets a set of rssis back and that then finger prints where you're standing with the phone (by the collection of rssis). the "space" it's locating in isn't physical space but "rssi tuple" space.
  - konschubert 9y ago
    So, how does it get mapped to physical space then? As long as I am in "rssi tuple" space, I maybe know if I am in a place where I have been before, and I can learn the topology of the place in terms of "which places are adjacent". But I can't put my location on a map. How do they do the mapping?
    - mlevental 9y ago
      >So, how does it get mapped to physical space then? don't quote me but i don't think it does. you basically go around and set up hotspots in rssi space that the server knows about. when other people enter that hotspot things happen. this isn't as silly as it sounds because for a lot of applications you don't need to know where you are in physical space but just what you're near (i.e. i put my tv somewhere, hotspot it, then when my phone gets near that hotspot it's near the tv).
      - coupdejarnac 9y ago
        Yeah, that makes sense. But that's not going to be very accurate. That will be accurate at the tuple space, but not down to the nearest centimeter in X Y coordinates or anything like that. Plus, if there is any mass between the marker and the tracked device, that will throw off readings. RSSI measurements are really only good for open air measurements or if you have characterized all the materials the rf passes through.
        mlevental 9y ago
        >lus, if there is any mass between the marker and the tracked device there are no markers so there is no attenuation happening in that way.
gricardo99 9y ago
Pardon the laymen’s questions, but my understanding of precision location is that it requires triangulation + accurate timestamps (the more accurate the more precise), plus with indoor the additional complexity of resolving signal multi path. There’s no mention of the hardware or “system” requirements. Possibly all modern smartphones and laptops have the necessary hardware? It would still be nice for this to mention a high level summary of the system required to set this up. How many devices to coordinate the location discovery?
- maxerickson 9y ago
  The timing is less important if some of the transmitters or receivers are fixed. GPS satellites are ambling along at 14,000 kph so they need pretty accurate timekeeping to get a precise position.
- qrv3w 9y ago
  > ...it requires triangulation + accurate timestamps... This system does not do round-trip time measurements (RTT) which I believe you are referring. RTT is different because it uses actual triangulation, whereas this system merely classifies a given point in space based on surrounding electromagnetic waves (WiFi/Bluetooth/etc.). RTT is superior, what I would call extreme precision, because it is capable of cm-level precision. (I say high-precision as compared to GPS which I tried to do this with before years ago). I love RTT, except that it is not a solution that is widely available yet. This FIND system is nice because anyone can use on their phone right now, and you don't know need any specialized hardware or need to buy any equipment. And the signal generators are already there (your WiFi, your neighbors WiFi, Bluetooth devices, etc.). > How many devices to coordinate the location discovery? In the active mode (where you do the scanning) it will use every device it sees in the vicinity. In a place like an apartment in the city, this would include all WiFi+Bluetooth points in your home and your neighbors, which could be dozens. > There's no mention of hardware or system requirements. Thanks, I'll fix this. It really depends on how you use FIND - in active mode you only need a computer or a Android smartphone. For passive mode you need some small computers and WiFi cards.
  - gricardo99 9y ago
mlevental 9y ago
pretty neat. how robust are the fingerprints across devices i wonder and whether this has been experimented in with strong multipath effects (thereby confounding fingerprinting). edit: another interesting thing is that this is basically context sensitive hashing of tuples being done using ml classification techinques
- qrv3w 9y ago
  > how robust are the fingerprints across devices I use this system to track phones and two different computers in my home without a problem, even though I learned only one device. The RSSI values are pretty well normalized so it works well. > strong multipath effects The signals need not be normally distributed to be effective. Because this is classification it doesn't matter if the distribution of signal levels is multimodal (i.e. it is composed of multiple signal values through multiple paths), as long as the distribution of signals are different from location to location.
bastijn 9y ago
Our (used to) lighting division is selling a product where we use our LED-lights to track phones indoor. Always thought it one of the coolest applications of our tech. Using the fact that we can control LED frequencies invisible to the human eye but visible to a phones camera to pinpoint devices and provide indoor navigation [0]. Accuracy was tested to be 30cm (when combined with a few other factors). [0] http://www.lighting.philips.com/main/systems/lighting-systems/indoor-positioning# http://www.lighting.philips.com/main/systems/lighting-system...
- arianvanp 9y ago
  Roosendaal by any chance? I remember visiting the lighting r&d department with school when I was young. Was one of the things that inspired me to go into tech! They demolished the entire factory now ...
  - bastijn 9y ago
    Not exactly sure where it was developed (I am working in the heathcare division). Today most of it is in Eindhoven. I would guess the R&D divisions in Eindhoven developed it but that is pure speculation.
    - bradknowles 9y ago
      ASML is in Eindhoven. I worked there for about a year, and they used to be a part of the Philips R&D group. So, that makes total sense.
- alanning 9y ago
  That is a very interesting approach to indoor positioning. The idea of just installing a light bulb seems very cost-effective. When you say, “used to” did you mean that the product was discontinued and/or isn’t available for purchase anymore? Or perhaps Philips sold the technology? I’d like to learn more, will use the Contact Us form on the page you linked but if there’s someone you could recommend that would be much appreciated.
trashcan 9y ago
Every URL I am trying on https://cloud.internalpositioning.com https://cloud.internalpositioning.com is reporting 502 bad gateway. Is the hosted service currently down?
- qrv3w 9y ago
  It was, should be back up now.
pimlottc 9y ago
Is there a more product-orientated page describing what this system is actually capable of?
- hyder_m29 9y ago
  https://www.internalpositioning.com/doc/overview.md https://www.internalpositioning.com/doc/overview.md
dimatura 9y ago
Does it do filtering over time?
- qrv3w 9y ago
  What do you mean by filtering?
nielsole 9y ago
Just be aware that the public server in the app has no access control. Your location will be published. You probably really want to set up a private server to use this in practice or even try it out. Otherwise looks promising. A nice addition to my home setup
- qrv3w 9y ago
  Thanks. I will add something across the system to highlight this. I want to encourage folks to run their own server [1] and use public cloud just for playing. [1]: https://www.internalpositioning.com/doc/server_setup.md https://www.internalpositioning.com/doc/server_setup.md Edit: For those who finished playing and now want to delete their data from the public server, I just added a DELETE endpoint: https://github.com/schollz/find3/blob/master/doc/api.md#delete-all-data--delete https://github.com/schollz/find3/blob/master/doc/api.md#dele...
toolbox 9y ago
Hey, I remember this project! I had the chance to give a bit of advice to the creator, Zach Scholl while I was working at Duke's Co-Lab [1]. It was cool then, and looks like it's only improved in robustness since (and it sounds like HN has plenty of ideas for PRs). Although I no longer work/learn at the Co-Lab I'd love to plug the value of these sorts of programs at schools. They give encouragement with money and publicity, and most importantly, tools (VMs/APIs) and advice ("why won't this compile?"/"where do we start?"). I had a chance to see and help with a lot of projects that wouldn't have otherwise been possible to get built. Hopefully it helped a few people get into hacking that wouldn't have otherwise too! [1]: colab.duke.edu
- qrv3w 9y ago
  Thanks! Yeah I think I would've never gotten the idea out of my idea without the support from Co-Lab.
sylwester 9y ago
I have created a find3 beacon/client for the cheap ESP8266/ESP32 microcontrollers yesterday and released it to the public. https://github.com/DatanoiseTV/esp-find3-client https://github.com/DatanoiseTV/esp-find3-client The ESP8266 uses WiFi and submits the BSSIDs and their RSSI to the server. The ESP32 version uses BLE probes additionally, which potentially improves accuracy. Any feedback is welcome. This is an early hack.
janOsch 9y ago
Can you integrate it with bluetooth beacons?
- qrv3w 9y ago
  Yes, the scanners available for Android and a computer both will scan for Bluetooth devices and use those for positioning as well.
kypro 9y ago
I wonder if the NSA has access to this kind of data at all. Theoretically if you could put a backdoor in iOS or Android you could create a nation-wide Wifi map to track people/devices with.
- Ajedi32 9y ago
  Google (and probably other companies) already uses WiFi data to supplement GPS: https://support.google.com/accounts/answer/6179507?hl=en https://support.google.com/accounts/answer/6179507?hl=en > To estimate location, it uses sources like Wi-Fi, mobile networks, and sensors.
  - sylwester 9y ago
    Just check out https://developers.google.com/maps/documentation/geolocation/intro#wifi_access_point_object https://developers.google.com/maps/documentation/geolocation... Feeding it with BSSIDs and RSSI, it gives you a precise response with GPS coordinates.
  - helb 9y ago
    There's also Mozilla Location Service – https://location.services.mozilla.com/ https://location.services.mozilla.com/ > […] an open service which lets devices determine their location based on network infrastructure like Bluetooth beacons, cell towers and WiFi access points
tyldum 9y ago
Really cool idea, and it works really well. Was able to do very precise positioning in my house, even within a single room if given multiple references. Ultimately it drained the phone battery too much to be of actual use for me in my smarthome.
- qrv3w 9y ago
  Can you provide some more details about the battery drainage? Namely, what kind of phone, how much battery usage you noticed? I've tested things with my Pixel2 and I get about 1-2%/hour battery usage.

265 points by qrv3w 9y ago

llao 9y ago

The byline says "High-precision" but I could not find any benchmarks or scientific analysis. What does high precision mean here? How stable is it? What about privacy of the users? Does the server know where everyone is?

consultutah 9y ago
Yep. Needs to answer what is the precision?
qrv3w 9y ago
The actual precision you get depends on context, as this system utilizes surrounding signals (Bluetooth/WiFi/etc.) in the given environment to classify the location. Generally rooms/walkways are easily distinguishable. Pieces of rooms are also usually distinguishable because of smart devices people generally acquire nowadays (e.g. a Google home at one side of the kitchen is sufficient). I say high-precision because I compare it to GPS, but if you compare it to round-trip time (RTT) measurements which get cm-level precision from specialized hardware, it is an order-of-magnitude behind. The public server knows the mac addresses of devices that they send to it, so in a sense it does know where they are (because those can be reversed with public wardriving databases). The public server does not have authentication, so if someone figures out your "family name" then they can see your data. I suggest using the public server to try FIND, but not to use FIND so I have instructions for setting up your own system. [1] I'll make this more clear in the docs. [1] https://www.internalpositioning.com/doc/server_setup.md https://www.internalpositioning.com/doc/server_setup.md

coupdejarnac 9y ago

Haven't read through the code yet, but the only thing I need to know is if these guys know what Rayleigh scattering is. If not, this probably isn't going to work so great. I worked on an indoor tracking system several years ago that used custom hardware. Since then, I've seen a lot of crappy solutions that use BLE RSSI measurements. This is simply not an easy problem to solve with crude methods.

mlevental 9y ago
they're fingerprinting locations based on rssi from devices in the signal environment. meaning your phone tries to connect, gets a set of rssis back and that then finger prints where you're standing with the phone (by the collection of rssis). the "space" it's locating in isn't physical space but "rssi tuple" space.
- konschubert 9y ago
  So, how does it get mapped to physical space then? As long as I am in "rssi tuple" space, I maybe know if I am in a place where I have been before, and I can learn the topology of the place in terms of "which places are adjacent". But I can't put my location on a map. How do they do the mapping?
  - mlevental 9y ago
    >So, how does it get mapped to physical space then? don't quote me but i don't think it does. you basically go around and set up hotspots in rssi space that the server knows about. when other people enter that hotspot things happen. this isn't as silly as it sounds because for a lot of applications you don't need to know where you are in physical space but just what you're near (i.e. i put my tv somewhere, hotspot it, then when my phone gets near that hotspot it's near the tv).
    - coupdejarnac 9y ago
      Yeah, that makes sense. But that's not going to be very accurate. That will be accurate at the tuple space, but not down to the nearest centimeter in X Y coordinates or anything like that. Plus, if there is any mass between the marker and the tracked device, that will throw off readings. RSSI measurements are really only good for open air measurements or if you have characterized all the materials the rf passes through.
      - mlevental 9y ago
        >lus, if there is any mass between the marker and the tracked device there are no markers so there is no attenuation happening in that way.

gricardo99 9y ago

Pardon the laymen’s questions, but my understanding of precision location is that it requires triangulation + accurate timestamps (the more accurate the more precise), plus with indoor the additional complexity of resolving signal multi path. There’s no mention of the hardware or “system” requirements. Possibly all modern smartphones and laptops have the necessary hardware? It would still be nice for this to mention a high level summary of the system required to set this up. How many devices to coordinate the location discovery?

maxerickson 9y ago
The timing is less important if some of the transmitters or receivers are fixed. GPS satellites are ambling along at 14,000 kph so they need pretty accurate timekeeping to get a precise position.
qrv3w 9y ago
> ...it requires triangulation + accurate timestamps... This system does not do round-trip time measurements (RTT) which I believe you are referring. RTT is different because it uses actual triangulation, whereas this system merely classifies a given point in space based on surrounding electromagnetic waves (WiFi/Bluetooth/etc.). RTT is superior, what I would call extreme precision, because it is capable of cm-level precision. (I say high-precision as compared to GPS which I tried to do this with before years ago). I love RTT, except that it is not a solution that is widely available yet. This FIND system is nice because anyone can use on their phone right now, and you don't know need any specialized hardware or need to buy any equipment. And the signal generators are already there (your WiFi, your neighbors WiFi, Bluetooth devices, etc.). > How many devices to coordinate the location discovery? In the active mode (where you do the scanning) it will use every device it sees in the vicinity. In a place like an apartment in the city, this would include all WiFi+Bluetooth points in your home and your neighbors, which could be dozens. > There's no mention of hardware or system requirements. Thanks, I'll fix this. It really depends on how you use FIND - in active mode you only need a computer or a Android smartphone. For passive mode you need some small computers and WiFi cards.
- gricardo99 9y ago

mlevental 9y ago

pretty neat. how robust are the fingerprints across devices i wonder and whether this has been experimented in with strong multipath effects (thereby confounding fingerprinting). edit: another interesting thing is that this is basically context sensitive hashing of tuples being done using ml classification techinques

qrv3w 9y ago
> how robust are the fingerprints across devices I use this system to track phones and two different computers in my home without a problem, even though I learned only one device. The RSSI values are pretty well normalized so it works well. > strong multipath effects The signals need not be normally distributed to be effective. Because this is classification it doesn't matter if the distribution of signal levels is multimodal (i.e. it is composed of multiple signal values through multiple paths), as long as the distribution of signals are different from location to location.

bastijn 9y ago

Our (used to) lighting division is selling a product where we use our LED-lights to track phones indoor. Always thought it one of the coolest applications of our tech. Using the fact that we can control LED frequencies invisible to the human eye but visible to a phones camera to pinpoint devices and provide indoor navigation [0]. Accuracy was tested to be 30cm (when combined with a few other factors). [0] http://www.lighting.philips.com/main/systems/lighting-systems/indoor-positioning# http://www.lighting.philips.com/main/systems/lighting-system...

arianvanp 9y ago
Roosendaal by any chance? I remember visiting the lighting r&d department with school when I was young. Was one of the things that inspired me to go into tech! They demolished the entire factory now ...
- bastijn 9y ago
  Not exactly sure where it was developed (I am working in the heathcare division). Today most of it is in Eindhoven. I would guess the R&D divisions in Eindhoven developed it but that is pure speculation.
  - bradknowles 9y ago
    ASML is in Eindhoven. I worked there for about a year, and they used to be a part of the Philips R&D group. So, that makes total sense.
alanning 9y ago
That is a very interesting approach to indoor positioning. The idea of just installing a light bulb seems very cost-effective. When you say, “used to” did you mean that the product was discontinued and/or isn’t available for purchase anymore? Or perhaps Philips sold the technology? I’d like to learn more, will use the Contact Us form on the page you linked but if there’s someone you could recommend that would be much appreciated.

trashcan 9y ago

Every URL I am trying on https://cloud.internalpositioning.com https://cloud.internalpositioning.com is reporting 502 bad gateway. Is the hosted service currently down?

qrv3w 9y ago
It was, should be back up now.

pimlottc 9y ago

Is there a more product-orientated page describing what this system is actually capable of?

hyder_m29 9y ago
https://www.internalpositioning.com/doc/overview.md https://www.internalpositioning.com/doc/overview.md

dimatura 9y ago

Does it do filtering over time?

qrv3w 9y ago
What do you mean by filtering?

nielsole 9y ago

Just be aware that the public server in the app has no access control. Your location will be published. You probably really want to set up a private server to use this in practice or even try it out. Otherwise looks promising. A nice addition to my home setup

qrv3w 9y ago
Thanks. I will add something across the system to highlight this. I want to encourage folks to run their own server [1] and use public cloud just for playing. [1]: https://www.internalpositioning.com/doc/server_setup.md https://www.internalpositioning.com/doc/server_setup.md Edit: For those who finished playing and now want to delete their data from the public server, I just added a DELETE endpoint: https://github.com/schollz/find3/blob/master/doc/api.md#delete-all-data--delete https://github.com/schollz/find3/blob/master/doc/api.md#dele...

toolbox 9y ago

Hey, I remember this project! I had the chance to give a bit of advice to the creator, Zach Scholl while I was working at Duke's Co-Lab [1]. It was cool then, and looks like it's only improved in robustness since (and it sounds like HN has plenty of ideas for PRs). Although I no longer work/learn at the Co-Lab I'd love to plug the value of these sorts of programs at schools. They give encouragement with money and publicity, and most importantly, tools (VMs/APIs) and advice ("why won't this compile?"/"where do we start?"). I had a chance to see and help with a lot of projects that wouldn't have otherwise been possible to get built. Hopefully it helped a few people get into hacking that wouldn't have otherwise too! [1]: colab.duke.edu

qrv3w 9y ago
Thanks! Yeah I think I would've never gotten the idea out of my idea without the support from Co-Lab.

sylwester 9y ago

I have created a find3 beacon/client for the cheap ESP8266/ESP32 microcontrollers yesterday and released it to the public. https://github.com/DatanoiseTV/esp-find3-client https://github.com/DatanoiseTV/esp-find3-client The ESP8266 uses WiFi and submits the BSSIDs and their RSSI to the server. The ESP32 version uses BLE probes additionally, which potentially improves accuracy. Any feedback is welcome. This is an early hack.

janOsch 9y ago

Can you integrate it with bluetooth beacons?

qrv3w 9y ago
Yes, the scanners available for Android and a computer both will scan for Bluetooth devices and use those for positioning as well.

kypro 9y ago

I wonder if the NSA has access to this kind of data at all. Theoretically if you could put a backdoor in iOS or Android you could create a nation-wide Wifi map to track people/devices with.

Ajedi32 9y ago
Google (and probably other companies) already uses WiFi data to supplement GPS: https://support.google.com/accounts/answer/6179507?hl=en https://support.google.com/accounts/answer/6179507?hl=en > To estimate location, it uses sources like Wi-Fi, mobile networks, and sensors.
- sylwester 9y ago
  Just check out https://developers.google.com/maps/documentation/geolocation/intro#wifi_access_point_object https://developers.google.com/maps/documentation/geolocation... Feeding it with BSSIDs and RSSI, it gives you a precise response with GPS coordinates.
- helb 9y ago
  There's also Mozilla Location Service – https://location.services.mozilla.com/ https://location.services.mozilla.com/ > […] an open service which lets devices determine their location based on network infrastructure like Bluetooth beacons, cell towers and WiFi access points

tyldum 9y ago

Really cool idea, and it works really well. Was able to do very precise positioning in my house, even within a single room if given multiple references. Ultimately it drained the phone battery too much to be of actual use for me in my smarthome.

qrv3w 9y ago
Can you provide some more details about the battery drainage? Namely, what kind of phone, how much battery usage you noticed? I've tested things with my Pixel2 and I get about 1-2%/hour battery usage.