8 ms·
Homemade GPS Receiver
- Quanticles 11y agoIf anyone is interested in GPS, we're looking for a software engineer ready to learn about it. (Full Time, Austin)
- shubb 11y agoTotally off topic but I'm seeing a lot of hiring going on in Texas. What is going on down there?
- natebleker 11y agoTax incentives, lower cost of living, and pro business local governments are driving larger companies to relocate headquarters or major research ops to Texas en-mass.
- toomuchtodo 11y agoPlease don't take this the wrong way, but Texas is a pretty terrible place to live: http://pastebin.com/Vt6vNgeS http://pastebin.com/Vt6vNgeS http://web.archive.org/web/20150401050939/https://www.texastribune.org/2011/02/14/texas-is-on-the-brink-legislative-study-group-says/ http://web.archive.org/web/20150401050939/https://www.texast...
- bryondowd 11y agoSounds like a great place to live, if you're privileged and don't care about the environment or the poor.
- CONTRARlAN 11y agoOr, perhaps you move there because you care about the environment or the poor, and that's how change happens.
- toomuchtodo 11y agoGonna need a whole lot more people to move there before any change occurs.
- pkaye 11y agoWell you need some way to pay for the tax subsidies.
- CONTRARlAN 11y agoAre those environmental stats per capita or area? I ask only because it's by far the largest state in the CONUS, which makes me wonder if that doesn't play a contributing role.
- sizzzzlerz 11y agoNot to mention a crazy governor who believes military exercises are a prelude to Obama taking over his state.
- Quanticles 11y agoIt's a big tech hub outside of silicon valley that's arguably more fun and undeniably less expensive
- Xeoncross 11y agoRight after CA, Texas is the highest GDP state. It's also has beautiful clouds and sunsets.
- amyjess 11y agoTexas has always had a huge tech industry presence, particularly the telecom industry: http://en.wikipedia.org/wiki/Telecom_Corridor http://en.wikipedia.org/wiki/Telecom_Corridor (and there's also a lot of tech industry here outside the Corridor proper, too) Personally, I love living and working in the suburbs of Dallas, and I wouldn't want to live anywhere else.
- deleted 11y ago[deleted]
- teekert 11y agoGoogle Fiber? (In Austin at least)
- jhayward 11y agoThe Texas economy has, until a few months ago, been booming due to shale oil & gas development. Add in no income tax and warm weather with young folks doing sporty things and it's fairly attractive. Austin has a somewhat robust semiconductor focus, with Freescale, AMD, Intel, and Apple present. Some low-power IOT type tech including Silicon Labs (Energy Micro), and Ambiq in addition to afore-mentioned Freescale. There are a few DOD/spook type shops, and some financial techs, such as Visa, Paypal, Netspend, etc.
- knodi123 11y agoThat sounds interesting, can you post more details? Experience, compensation, requirements, description, etc?
- Quanticles 11y agoIsocline - Austin, TX - Software Engineer for High Performance Computing and Modeling We are looking for two people - one interested in neural networks and one interested in GPS. We are developing microchips that yield a 10-1000x improvement in performance & energy-efficiency compared to digital ASICs, GPUs, and FPGAs. We are a bootstrapped company and are fully funded through mid 2016. Patents pending. C++ experience is required! $70K – $150K Salary 0.5% – 1.2% Equity Full Job Description: https://angel.co/isocline/jobs/38767-software-engineer https://angel.co/isocline/jobs/38767-software-engineer Company website: http://isoclineengineering.com/ http://isoclineengineering.com/
- hobolord 11y agoUS citizens only? (since it's a defense company)
- jkot 11y agoI would be bit careful. GPS is military technology and commercial versions must have limitations, to be non-usable in rockets (max speed, max altitude...).
- tyho 11y agoSays the USA, thankfully the author is not based there. That being said, the USA does seem to think many of its laws apply all over the globe.
- ape4 11y agoHe might want to visit the USA some time.
- ceequof 11y agoIncorrect. The relevant agreement is the Missile Technology Control Regime, an informal partnership between 34 countries. http://en.wikipedia.org/wiki/Missile_Technology_Control_Regime http://en.wikipedia.org/wiki/Missile_Technology_Control_Regi... Unlocked GPS receivers are classified as dual-use missile-related components under category II, item 11, section A.3: http://www.mtcr.info/english/MTCR-April2011-Technical-Annex.pdf http://www.mtcr.info/english/MTCR-April2011-Technical-Annex.... b. Designed or modified for airborne applications and having any of the following: 1. Capable of providing navigation information at speeds in excess of 600 m/s; 2. Employing decryption, designed or modified for military or governmental services, to gain access to GNSS secure signal/data; or 3. Being specially designed to employ anti-jam features (e.g. null steering antenna or electronically steerable antenna) to function in an environment of active or passive countermeasures.
- tyho 11y agoHuh, I should have checked that first. How well do you think you could argue that since the treaty did not specify what reference frame you were supposed to use to calculate the 600 m/s limit, you decided to use the reference frame of the receiver and therefore no limit is required because the speed is always 0? I would have thought GPS people most of all would have understood this problem \s.
- vinhboy 11y agoA while back I was interested in building a DIY GPS after watching Lost. I day-dreamed about being stranded somewhere remote and building myself a GPS out of spare parts like MacGyver or something. After finding this article, I realized that would be an impossible task without an engineering degree. Has anyone found a more "For Dummies" version of this?
- krapht 11y agoI don't know if "For Dummies" is possible for building a GPS system from first principles. If you want to really learn by building, I recommend "Fundamentals of GPS Receivers: A Hardware Approach" by Dan Doberstein, and building the analog GPS system described in the first few chapters. If you simply want to play with GPS, I'm sure there are many breakout modules from Adafruit et al.
- contingencies 11y agoGPS system from first principles. To be fair, that would probably be navigation by naturally observable indicators such as the rising or setting sun, shadows over the day, locally / seasonally reliable stars for your area, and knowledge of local fauna/wave patterns. After getting interested in sailing again (after 20 years) last year through multihull vessels, I started reading about the evolution of multihulls in the Pacific and then began looking at traditional navigation techniques. Following that, I was wondering for fun whether it would be possible to plot one's position given a rough time, rough position guestimate, and perfectly measured horizonal inclination, lens property and visible to 'the naked eye' star positions (ie. visible to the naked CCD at evening time = high ISO, noise and short shutter speed to failitate clarity in rough seas). My conclusion was yes, it's possible, with sub-GPS accuracy but accuracy which would be good enough to get you reliably between certain locations in certain seasons even on a sailboat. I was surprised to read that some ICBMs allegedly used astronomy and pre-loaded landform navigation to avoid issues with jamming, and that fat databases of precise naked-eye type visible star locations are widely available, indeed so is software for reducing them to identities from an image input.
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- bainsfather 11y ago"The best fix so far was ±1 metres at a very open location using 12 satellites; but accuracy is typically ±5 metres in poorer locations with fewer satellites." That seems very good accuracy. The off-the-shelf GPS I have (https://www.adafruit.com/products/746 https://www.adafruit.com/products/746) is always >= ±5m, even with 360 degree view of the sky. (the specs for my GPS claim < 3 meters, and also say "(all GPS technology has about 3m accuracy)").
- CONTRARlAN 11y agoCommercial-grade technology has about 3m accuracy, but different methods can yield down to 10cm accuracy: https://en.wikipedia.org/wiki/Global_Positioning_System#Precise_monitoring https://en.wikipedia.org/wiki/Global_Positioning_System#Prec... And then there's a whole segment of survey-grade equipment that can get within a centimeter or two: http://water.usgs.gov/osw/gps/ http://water.usgs.gov/osw/gps/
- jhayward 11y agoThat MediaTek chip is capable of better. Do you have WAAS (SBAS) enabled? 5m is about what you'd expect without the improved orbit/clock/ionosphere corrections. It also pays off to use a good antenna, or at least put a ground plane beneath a mediocre one to block multipath reflections from the surrounding ground objects.
- bainsfather 11y agoI just used the default settings. Didn't know about WAAS - thanks for pointing me to it. From reading some forum posts, it seems you have to explicitly enable WAAS - I'll give that a try and see how much it helps.
- jevinskie 11y agoThe author got a lot further than my attempt! [0] I was attempting to make a Python-based GPS signal generator for later use in testing a pure VHDL/FPGA (no embedded CPU) receiver. [0]: https://github.com/jevinskie/jevps https://github.com/jevinskie/jevps