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Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic

211 points by ChopSticksPlz 2y ago

oliver_jack 2y ago
[flagged]
fellerts 2y ago
Fun project! Did you look into NTN (Non-Terrestrial Networks) capable modules as an alternative to Iridium? I haven't played with NTN myself, but it seems modules such as SIM7070G-HP-S support LTE-M/NB-IoT as well as NTN networks, and could in theory serve the purpose of your Iridium tranceiver as well as your LTE module. This technology hasn't matured yet, and I suspect the roaming tarriffs are expensive, but I don't know how it compares to Iridium.
- lxgr 2y ago
  NTN seems to be only offered by geostationary satellite operators at this point, which unfortunately puts the use case from TFA out of coverage. See for example Inmarsat's coverage: https://www.inmarsat.com/content/dam/inmarsat/corporate/core-assets/coverage-maps/document/ELERA_BGAN_and_BGAN_M2M_coverage.pdf https://www.inmarsat.com/content/dam/inmarsat/corporate/core... I'm not even sure if Skylo is live with Inmarsat at this point, or if there are any other NTN providers covering oceans.
keepamovin 2y ago
This is so cool! Thanks for sharing and creating something like this :) BTW do you use Iridium handsets? Do you have recommendations?
- lxgr 2y ago
  OP is using Iridium SBD according to the article, specifically this modem: https://www.groundcontrol.com/product/rockblock-9603-compact-plug-and-play-satellite-transmitter/ https://www.groundcontrol.com/product/rockblock-9603-compact...
  - keepamovin 2y ago
    Oh ok, I mean I got they were using some special build for the project. But based on them saying "I often go all around the world" (to the effect of that), seemed they'd probably be using handsets, outside of the article.
KMnO4 2y ago
For anyone else wondering, the satellite transceiver is a RockBoard, which charges: - $302 for the hardware - $17/month for a “line fee” - $0.20/message (50 characters) Would be nice if there was an actually affordable, programmable Iridium device.
- causal 2y ago
  I've been wondering how Iridium costs are tallied. Recently had two calls with an Iridium phone, one sent and one received, about 1 minute each. T-Mobile charged me $50 for those. I found it very odd - it seemed like Iridium was somehow passing the call fees onto me, but I can't be sure because the T-Mobile rep I chatted with was unable to comprehend the situation (I suspect I was talking to an LLM, but it ultimately gave me a $30 rebate at least).
  - slaucon 2y ago
    I’ve had to make and pay for an unfortunate number of Iridium calls. They can be crazy expensive depending on carrier, who all bill them as a call to an international line in the country of “Satellite”. Usually you pay your carrier’s fee for outgoing and it’s cheaper/free to receive the calls. It seems like cell carriers always charge more per minute for satellite calls than any satellite provider does, so I’m guessing they just set their rates conservatively to always make a profit on their end. And the demand for satellite calls seems like it would be pretty inelastic.
    - 0xffff2 2y ago
      I've always assumed that answering a phone call would be free for me (excepting the dawn of cell phones when they had a limited number of minutes per month). If answering a sat-phone call is "cheaper" rather than free, does anything warn me that I'm incurring extra charges?
      - LeoPanthera 2y ago
        Paying to receive a call seems to a mostly American phenomenon. In most (all?) of Europe, receiving calls is always free, no matter where or how they originate.
tylergetsay 2y ago
saveitforparts on youtube recently setup an old satellite terminal and went through the pricing of doing so, its expensive. https://www.youtube.com/watch?v=yzTPZLtmSOM&t=664s https://www.youtube.com/watch?v=yzTPZLtmSOM&t=664s
polishdude20 2y ago
>The ultimate motivator for building this project was the opportunity to join the crew of the S/Y Southern Star yacht, which sails in the Arctic. Anyone know how he got this opportunity? I'd love to join something like this if all I had to do was make a cool Iridium transmitter!
amlozano 2y ago
This is a very cool project, happy to see the costs of this stuff coming down a little bit. When I was an intern 15 years ago I worked on a software library for this https://www.embeddedts.com/products/TS-IRIDIUM https://www.embeddedts.com/products/TS-IRIDIUM Board that does a similar thing (though you would need to stack on a cellular board if you wanted cell modems). We used them to help Arizona Department of Transportation collect traffic data in remote locations. We had big plans at that company to make a much smaller, much cheaper 9602 transceiver replacement, but the company got bought out before that could launch.
thunder-blue-3 2y ago
Hearing about Iridium reminded me of how excited I was to take on a job managing 5 engineers for them, until they offered me a base salary of $135,000 in Phoenix. They work on incredibly cool technology—I'm bummed I had to pass it up to work for some garbage web-focused tech company becayse Iridium pays pennies on the dollar to their engineering department.
- 0xffff2 2y ago
  Is it just me, or does the wording of this comment imply that you passed up the Iridium job to work somewhere else that underpays their engineers? Seems like you meant to imply the opposite.
  - supportengineer 2y ago
    I think it's clear he has to work for the "garbage" company because it paid more than Iridium did
  - barkerja 2y ago
    The opposite. Op would have preferred to work at Iridium, if only they offered higher pay compared to where they are currently.
  - thunder-blue-3 2y ago
    yeah I meant Iridium pays pennies on the dollar -
- deleted 2y ago
  [deleted]
- diggan 2y ago
  > until they offered me a base salary of $135,000 in Phoenix It's crazy to me that $11,250/month could be considered low for a comfy job like engineering manager, especially if the work is interesting. The cost of living in Phoenix must be through the roof?
  - 2y ago
thadt 2y ago
Ah, that's cool. We built a similar system using Iridium SBD and LTE for controlling drones a few years back. SBD isn't the fastest comms around, and it can get rough if you don't have clear sky view, but it works pretty much everywhere, with a small antenna. If you don't have line of sight or LTE, it's a solid fallback.
- tbone902 2y ago
  [dead]
  - thadt 2y ago
    Their constellation wasn't deployed when we were building it. Also this would have been a non-starter: > Swarm is easy to use and lower cost, but the latency for message delivery is significantly longer, potentially several hours.
lormayna 2y ago
Why not trying using something like WSPR? It really depends from the propagation conditions, but it would be interesting IMHO
xadren 2y ago
Very cool project! The company I work for is building a similar sat/cell GPS tracker for civil aviation. In fact we're using the same GPS and Iridium modules. The costs for satellite SBD messages is definitely eye-watering though. Our device transmits position data every 2 minutes while relying on satellite connections, which we definitely notice the costs of during development. We'd like to look at other providers, but for various reasons (excluding costs) they end up being less ideal than Iridium.
LeoPanthera 2y ago
If you have an amateur radio license, a small HF transmitter would probably successfully send a signal to a receiver on land most of the time, and of course wouldn't cost anything. HF propagation does vary over time, but you could send a signal far more often to make up for it.
jviotti 2y ago
Great stuff! I'm starting to work a lot on the satellite space (https://www.sourcemeta.com https://www.sourcemeta.com), building a binary serialization format around JSON called JSON BinPack (https://jsonbinpack.sourcemeta.com https://jsonbinpack.sourcemeta.com) that is extremely space-efficient to pack more documents in the same Iridium uplink/downlink operation (up to 74% more compact than Protocol Buffers. See reproducible benchmark here: https://arxiv.org/abs/2211.12799 https://arxiv.org/abs/2211.12799). It is still a heavy work in progress, but if anybody here is suffering from expensive Iridium bills, I would love to connect and discuss to make sure JSON BinPack is built the right way!
- thadt 2y ago
  Hey Juan, this looks promising - using a pre-shared schema would allow you to reduce payload sizes in the same way using pre-shared dictionaries makes compression more efficient (such as with zstd or brotli). Having worked on exactly this space in the past (sending and receiving messages from a microcontroller that eventually go through an Iridium SBD modem), some feedback: After spending a few minutes poking around your landing page, I'm not sure how JSON BinPack works. I see a JSON Schema, a JSON document and then a payload, but I'd be interested in the low level details of how I get from a schema to a payload. When I'm on a microcontroller, I'm going to care quite a bit about the code that has to run to make that, and also the code that's receiving it. Is this something I could hand-jam on the micro, and then decode with a nice schema on the receiving side? Understanding the path from code and data to serialized payload would be important to me. One thing that was nice about using ProtocolBuffers for this was that I had libraries at hand to encode/decode messages in several different languages (which were used) - what is the roadmap or current language support? I can understand how ProtocolBuffers handles schema evolution, but I'm still not sure how JSON Schema evolution would work with JSON BinPack. An example would move mountains. Finally, if I were digging into this and found it had switched from Apache to AGPL, and required a commercial license, it would be a hard sell vs all the permissively licensed alternatives. At the end of the day, Iridium SBD messages are like 270 bytes and even hand rolling a binary format is pretty manageable. I think I could swing budget for support, consulting, maintenance or some other service. But if I were evaluating this back when I needed a serialization format, and ran into AGPL, I would bounce almost immediately.
allendave6945 2y ago
[flagged]

211 points by ChopSticksPlz 2y ago

[flagged]

Fun project! Did you look into NTN (Non-Terrestrial Networks) capable modules as an alternative to Iridium? I haven't played with NTN myself, but it seems modules such as SIM7070G-HP-S support LTE-M/NB-IoT as well as NTN networks, and could in theory serve the purpose of your Iridium tranceiver as well as your LTE module. This technology hasn't matured yet, and I suspect the roaming tarriffs are expensive, but I don't know how it compares to Iridium.

lxgr 2y ago
NTN seems to be only offered by geostationary satellite operators at this point, which unfortunately puts the use case from TFA out of coverage. See for example Inmarsat's coverage: https://www.inmarsat.com/content/dam/inmarsat/corporate/core-assets/coverage-maps/document/ELERA_BGAN_and_BGAN_M2M_coverage.pdf https://www.inmarsat.com/content/dam/inmarsat/corporate/core... I'm not even sure if Skylo is live with Inmarsat at this point, or if there are any other NTN providers covering oceans.

keepamovin 2y ago

This is so cool! Thanks for sharing and creating something like this :) BTW do you use Iridium handsets? Do you have recommendations?

lxgr 2y ago
OP is using Iridium SBD according to the article, specifically this modem: https://www.groundcontrol.com/product/rockblock-9603-compact-plug-and-play-satellite-transmitter/ https://www.groundcontrol.com/product/rockblock-9603-compact...
- keepamovin 2y ago
  Oh ok, I mean I got they were using some special build for the project. But based on them saying "I often go all around the world" (to the effect of that), seemed they'd probably be using handsets, outside of the article.

KMnO4 2y ago

For anyone else wondering, the satellite transceiver is a RockBoard, which charges: - $302 for the hardware - $17/month for a “line fee” - $0.20/message (50 characters) Would be nice if there was an actually affordable, programmable Iridium device.

causal 2y ago
I've been wondering how Iridium costs are tallied. Recently had two calls with an Iridium phone, one sent and one received, about 1 minute each. T-Mobile charged me $50 for those. I found it very odd - it seemed like Iridium was somehow passing the call fees onto me, but I can't be sure because the T-Mobile rep I chatted with was unable to comprehend the situation (I suspect I was talking to an LLM, but it ultimately gave me a $30 rebate at least).
- slaucon 2y ago
  I’ve had to make and pay for an unfortunate number of Iridium calls. They can be crazy expensive depending on carrier, who all bill them as a call to an international line in the country of “Satellite”. Usually you pay your carrier’s fee for outgoing and it’s cheaper/free to receive the calls. It seems like cell carriers always charge more per minute for satellite calls than any satellite provider does, so I’m guessing they just set their rates conservatively to always make a profit on their end. And the demand for satellite calls seems like it would be pretty inelastic.
  - 0xffff2 2y ago
    I've always assumed that answering a phone call would be free for me (excepting the dawn of cell phones when they had a limited number of minutes per month). If answering a sat-phone call is "cheaper" rather than free, does anything warn me that I'm incurring extra charges?
    - LeoPanthera 2y ago
      Paying to receive a call seems to a mostly American phenomenon. In most (all?) of Europe, receiving calls is always free, no matter where or how they originate.

tylergetsay 2y ago

saveitforparts on youtube recently setup an old satellite terminal and went through the pricing of doing so, its expensive. https://www.youtube.com/watch?v=yzTPZLtmSOM&t=664s https://www.youtube.com/watch?v=yzTPZLtmSOM&t=664s

polishdude20 2y ago

>The ultimate motivator for building this project was the opportunity to join the crew of the S/Y Southern Star yacht, which sails in the Arctic. Anyone know how he got this opportunity? I'd love to join something like this if all I had to do was make a cool Iridium transmitter!

amlozano 2y ago

This is a very cool project, happy to see the costs of this stuff coming down a little bit. When I was an intern 15 years ago I worked on a software library for this https://www.embeddedts.com/products/TS-IRIDIUM https://www.embeddedts.com/products/TS-IRIDIUM Board that does a similar thing (though you would need to stack on a cellular board if you wanted cell modems). We used them to help Arizona Department of Transportation collect traffic data in remote locations. We had big plans at that company to make a much smaller, much cheaper 9602 transceiver replacement, but the company got bought out before that could launch.

thunder-blue-3 2y ago

Hearing about Iridium reminded me of how excited I was to take on a job managing 5 engineers for them, until they offered me a base salary of $135,000 in Phoenix. They work on incredibly cool technology—I'm bummed I had to pass it up to work for some garbage web-focused tech company becayse Iridium pays pennies on the dollar to their engineering department.

0xffff2 2y ago
Is it just me, or does the wording of this comment imply that you passed up the Iridium job to work somewhere else that underpays their engineers? Seems like you meant to imply the opposite.
- supportengineer 2y ago
  I think it's clear he has to work for the "garbage" company because it paid more than Iridium did
- barkerja 2y ago
  The opposite. Op would have preferred to work at Iridium, if only they offered higher pay compared to where they are currently.
- thunder-blue-3 2y ago
  yeah I meant Iridium pays pennies on the dollar -
deleted 2y ago
[deleted]
diggan 2y ago
> until they offered me a base salary of $135,000 in Phoenix It's crazy to me that $11,250/month could be considered low for a comfy job like engineering manager, especially if the work is interesting. The cost of living in Phoenix must be through the roof?
- 2y ago

thadt 2y ago

Ah, that's cool. We built a similar system using Iridium SBD and LTE for controlling drones a few years back. SBD isn't the fastest comms around, and it can get rough if you don't have clear sky view, but it works pretty much everywhere, with a small antenna. If you don't have line of sight or LTE, it's a solid fallback.

tbone902 2y ago
[dead]
- thadt 2y ago
  Their constellation wasn't deployed when we were building it. Also this would have been a non-starter: > Swarm is easy to use and lower cost, but the latency for message delivery is significantly longer, potentially several hours.

lormayna 2y ago

Why not trying using something like WSPR? It really depends from the propagation conditions, but it would be interesting IMHO

xadren 2y ago

Very cool project! The company I work for is building a similar sat/cell GPS tracker for civil aviation. In fact we're using the same GPS and Iridium modules. The costs for satellite SBD messages is definitely eye-watering though. Our device transmits position data every 2 minutes while relying on satellite connections, which we definitely notice the costs of during development. We'd like to look at other providers, but for various reasons (excluding costs) they end up being less ideal than Iridium.

LeoPanthera 2y ago

If you have an amateur radio license, a small HF transmitter would probably successfully send a signal to a receiver on land most of the time, and of course wouldn't cost anything. HF propagation does vary over time, but you could send a signal far more often to make up for it.

jviotti 2y ago

Great stuff! I'm starting to work a lot on the satellite space (https://www.sourcemeta.com https://www.sourcemeta.com), building a binary serialization format around JSON called JSON BinPack (https://jsonbinpack.sourcemeta.com https://jsonbinpack.sourcemeta.com) that is extremely space-efficient to pack more documents in the same Iridium uplink/downlink operation (up to 74% more compact than Protocol Buffers. See reproducible benchmark here: https://arxiv.org/abs/2211.12799 https://arxiv.org/abs/2211.12799). It is still a heavy work in progress, but if anybody here is suffering from expensive Iridium bills, I would love to connect and discuss to make sure JSON BinPack is built the right way!

thadt 2y ago
Hey Juan, this looks promising - using a pre-shared schema would allow you to reduce payload sizes in the same way using pre-shared dictionaries makes compression more efficient (such as with zstd or brotli). Having worked on exactly this space in the past (sending and receiving messages from a microcontroller that eventually go through an Iridium SBD modem), some feedback: After spending a few minutes poking around your landing page, I'm not sure how JSON BinPack works. I see a JSON Schema, a JSON document and then a payload, but I'd be interested in the low level details of how I get from a schema to a payload. When I'm on a microcontroller, I'm going to care quite a bit about the code that has to run to make that, and also the code that's receiving it. Is this something I could hand-jam on the micro, and then decode with a nice schema on the receiving side? Understanding the path from code and data to serialized payload would be important to me. One thing that was nice about using ProtocolBuffers for this was that I had libraries at hand to encode/decode messages in several different languages (which were used) - what is the roadmap or current language support? I can understand how ProtocolBuffers handles schema evolution, but I'm still not sure how JSON Schema evolution would work with JSON BinPack. An example would move mountains. Finally, if I were digging into this and found it had switched from Apache to AGPL, and required a commercial license, it would be a hard sell vs all the permissively licensed alternatives. At the end of the day, Iridium SBD messages are like 270 bytes and even hand rolling a binary format is pretty manageable. I think I could swing budget for support, consulting, maintenance or some other service. But if I were evaluating this back when I needed a serialization format, and ran into AGPL, I would bounce almost immediately.

allendave6945 2y ago

[flagged]