8 ms·

There's no profitability from navigation? Starlink could charge a massive premium for high resolution GPS.

by axg11 4y ago

arsome 4y ago
But GPS is already so widely deployed and you can't really compete with free.
- ceejayoz 4y ago
  If someone starts taking out the 24 GPS satellites - a new anti-satellite weapon, or an interceptor satellite like the X-37 is speculated to be - being able to do it off Starlink's thousands as a backup would be extremely appealing to the US government. (After all, this is the same organization that's happy to pay out the nose to keep ULA alive to have redundant launch options.)
  - manquer 4y ago
    GPS satellites don’t sit in LEO . All ASAT weapons demonstrated so far by any country has been only for LEO based satellites.
    - ceejayoz 4y ago
      That would be why I said "new", yes. Given that we can get satellites to GEO, we can presumably get one that goes boom up there, should we be so inclined.
      - manquer 4y ago
        It is not that simple, the high orbits mean it is very very difficult for solid propellant based ICBM variants to reach with a meaningful payload, also given the orbits it is much easier to perform early detection and make evasive maneuvers. Also remember even if you did launch on liquid rockets, It is not easy to launch them in quick succession or with stealth. Liquid rockets needs a lot of time to load fuel, needs a ton of auxiliary equipment( cryogenic fuel storage at-least) and have limited shelf life once loaded which means they are limited to few known sites which you can quickly take offline after the first attack/launch. Solid rockets/ICBMs can be launched from variety of platforms some of them very mobile and also given their lower footprint - Silos and other sites can be hidden and missiles moved around to retain the strike capability. ASATs are primarily designed to target low flying spy sats[1], taking few key ones out can at the right time can potentially deliver few hours of advantage in a battle before alternative sats can be rerouted. Communication and navigation sats on the other hand are designed to operate even during normal times when few go offline without loss of operational capabilities . [1] Also this is much easier to justify domestically and globally than say communication ones even if they were dual use.
dahfizz 4y ago
The US military would come down on them pretty hard. We already have premium high resolution GPS. Its for military use only.
- pcl 4y ago
  I don’t think that’s true any more. IIRC, the high resolution codes were disclosed to the public in the late 90s / early 00s, and there have been no efforts to rotate them since. Extra precision can be achieved with fixed-point augmentation signals, which I believe is common at airports and construction sites. I would assume the at militaries similarly augment signals in theaters of war. But that’s different than some separate high-resolution mode. At this point, so many civilian services depend on the high-resolution data that I’d be pretty surprised to see GPS going back to a two-tier system. A citation for the above: “In May 2000, at the direction of President Bill Clinton, the U.S. government ended its use of Selective Availability in order to make GPS more responsive to civil and commercial users worldwide. “The United States has no intent to ever use Selective Availability again.” https://www.gps.gov/systems/gps/performance/accuracy/ https://www.gps.gov/systems/gps/performance/accuracy/
  - RegnisGnaw 4y ago
    There is already a 2 tier system. Clinton turned off "Selective Availability" but kept the P(Y) code for military only use. The P(Y) code now has been supplemented by an M code for military on the newer generation of GPS.
  - dhsysusbsjsi 4y ago
    The way GPS was designed to work originally is two sets of codes. Course Acquisition (CA) code which repeats at 300ms intervals with a deliberate bias was designed to bootstrap the receiver into locating its position in a 1-week Precise (P) long code. This bias was selectively worse in different regions and I think still can be changed in war zones. Happy to be educated further here! What the US government did was remove the bias from the CA code so it could be used for precise positioning. The military still uses P codes as well. I believe there is a small gain to be had but it’s due to frequencies. Since then there have been several more advances, mostly to broadcast local augmentation signals. Wide Area (WAAS) and Ground Bases (GBAS) are common in receivers. L5 is a new band to help solve multipath error in urban areas. Most receivers also have remote autonomous integrity monitoring, where it can predict its own area of probability (by using groupings of 4 in 5 satellites), and if it’s too large for the intended use case, alert the user. Also with 6 satellites it can calculate combinations of 5 satellite groupings to work out (and exclude) faulty satellites. This is Fault Detection & Exclusion (FDE). Mobile devices will also download their own separate high resolution almanac and ionospheric data over the internet which is superior to the low data rate GPS almanac. It can also use known cell locations to approximate its position. Combined, this enables rapid (hot) signal lock immediately onto the correct satellite code & Doppler shift frequency, which is why your mobile gets a fix in 3 seconds, versus your car which takes minutes.
stevehawk 4y ago
high resolution gps already exists. lookup WAAS
- NKosmatos 4y ago
  https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System "Currently, WAAS satellite coverage is only available in North America"
  - oritsnile 4y ago
    There is also the European version of this EGNOS, besides there also private Providers like TerraStar
- jrockway 4y ago
  WAAS is nice but dual-band receivers provide similar accuracy levels without needing to see that satellite. Ublox quotes on their ZED-F9P datasheet 1.5m accuracy for GPS+GLONASS+Galileo+BeiDou, increasing to 1m accuracy if using space-based augmentation (WAAS, EGNOSS, MSAS, GAGAN). Even without a SBAS, if you can do RTK, you can get 0.01m accuracy. (The corrections from a nearby reference station are even better than what you can get from a satellite.) RTK is probably more available than people think. My state offers a public network of continuously-operating reference stations; you can sign up for a free account and then do whatever RTK madness you desire. https://cors.dot.ny.gov/ https://cors.dot.ny.gov/ if you happen to be in New York. (I realize now that I really wanted to reply to the person complaining about not being in North America, but oh well, maybe they'll find this.)
  - mindslight 4y ago
    But the state-run reference stations are generally too far away from you to get that sweet sweet 1cm accuracy... It's amazing what you can do with consumer-priced gear these days. I set up a Sparkfun ZED-F9P breakout board as a fixed beacon on my roof, and then their "RTK Facet" as the rover to do precise measurements to create a map. I could have done the basic thing I needed to by hiring a surveyor or eyeballing things with a tape measure, but this is much more general. The GNSS software world seems to be a mess though, ripe for a paradigm shift. For example, QGIS seems to be based on flat projections with transformations rather than 3d-native - from what I can tell, QGIS seems to consider the "degree" to be a unit of length measurement! This leads to ridiculous things like being able to accidentally measure a nonsensical "cartesian" distance between two points that differs from the actual distance by a factor dependent on latitude. I've still got to tidy up my own pipeline that lets me do things like turn N (point, distance) samples into a single point. I would have thought that type of operation would be common, but thinking about how surveyors work I guess they're usually locating points optically, rather than trying to position a GPS receiver at the point to be measured.
KaiserPro 4y ago
> Starlink could charge a massive premium for high resolution GPS. but then they'd have to make it reliable. We are also not sure how much more (if at all) accurate it is. sure the bandwidth of the downlink is much higher, and louder than GPS, but the accuracy of the clocks on the satellites is much less. More importantly they are not characterised, so we arn't sure how much they drift due to temperature (both from sun and other effects.) depending on the navigation type, visual positioning might be better/faster/more accurate. For "military" purposes, silent autonomous navigation without radio sensors is pretty appealing. Using satellite imagery, its perfectly possible to make an accurate, robust visual navigation system for urban areas, "VPS"s are far quicker and more accurate, but require network access to work practically.

There's no profitability from navigation? Starlink could charge a massive premium for high resolution GPS.

by axg11 4y ago

There's no profitability from navigation? Starlink could charge a massive premium for high resolution GPS.

arsome 4y ago

But GPS is already so widely deployed and you can't really compete with free.

ceejayoz 4y ago
If someone starts taking out the 24 GPS satellites - a new anti-satellite weapon, or an interceptor satellite like the X-37 is speculated to be - being able to do it off Starlink's thousands as a backup would be extremely appealing to the US government. (After all, this is the same organization that's happy to pay out the nose to keep ULA alive to have redundant launch options.)
- manquer 4y ago
  GPS satellites don’t sit in LEO . All ASAT weapons demonstrated so far by any country has been only for LEO based satellites.
  - ceejayoz 4y ago
    That would be why I said "new", yes. Given that we can get satellites to GEO, we can presumably get one that goes boom up there, should we be so inclined.
    - manquer 4y ago
      It is not that simple, the high orbits mean it is very very difficult for solid propellant based ICBM variants to reach with a meaningful payload, also given the orbits it is much easier to perform early detection and make evasive maneuvers. Also remember even if you did launch on liquid rockets, It is not easy to launch them in quick succession or with stealth. Liquid rockets needs a lot of time to load fuel, needs a ton of auxiliary equipment( cryogenic fuel storage at-least) and have limited shelf life once loaded which means they are limited to few known sites which you can quickly take offline after the first attack/launch. Solid rockets/ICBMs can be launched from variety of platforms some of them very mobile and also given their lower footprint - Silos and other sites can be hidden and missiles moved around to retain the strike capability. ASATs are primarily designed to target low flying spy sats[1], taking few key ones out can at the right time can potentially deliver few hours of advantage in a battle before alternative sats can be rerouted. Communication and navigation sats on the other hand are designed to operate even during normal times when few go offline without loss of operational capabilities . [1] Also this is much easier to justify domestically and globally than say communication ones even if they were dual use.

dahfizz 4y ago

The US military would come down on them pretty hard. We already have premium high resolution GPS. Its for military use only.

pcl 4y ago
I don’t think that’s true any more. IIRC, the high resolution codes were disclosed to the public in the late 90s / early 00s, and there have been no efforts to rotate them since. Extra precision can be achieved with fixed-point augmentation signals, which I believe is common at airports and construction sites. I would assume the at militaries similarly augment signals in theaters of war. But that’s different than some separate high-resolution mode. At this point, so many civilian services depend on the high-resolution data that I’d be pretty surprised to see GPS going back to a two-tier system. A citation for the above: “In May 2000, at the direction of President Bill Clinton, the U.S. government ended its use of Selective Availability in order to make GPS more responsive to civil and commercial users worldwide. “The United States has no intent to ever use Selective Availability again.” https://www.gps.gov/systems/gps/performance/accuracy/ https://www.gps.gov/systems/gps/performance/accuracy/
- RegnisGnaw 4y ago
  There is already a 2 tier system. Clinton turned off "Selective Availability" but kept the P(Y) code for military only use. The P(Y) code now has been supplemented by an M code for military on the newer generation of GPS.
- dhsysusbsjsi 4y ago
  The way GPS was designed to work originally is two sets of codes. Course Acquisition (CA) code which repeats at 300ms intervals with a deliberate bias was designed to bootstrap the receiver into locating its position in a 1-week Precise (P) long code. This bias was selectively worse in different regions and I think still can be changed in war zones. Happy to be educated further here! What the US government did was remove the bias from the CA code so it could be used for precise positioning. The military still uses P codes as well. I believe there is a small gain to be had but it’s due to frequencies. Since then there have been several more advances, mostly to broadcast local augmentation signals. Wide Area (WAAS) and Ground Bases (GBAS) are common in receivers. L5 is a new band to help solve multipath error in urban areas. Most receivers also have remote autonomous integrity monitoring, where it can predict its own area of probability (by using groupings of 4 in 5 satellites), and if it’s too large for the intended use case, alert the user. Also with 6 satellites it can calculate combinations of 5 satellite groupings to work out (and exclude) faulty satellites. This is Fault Detection & Exclusion (FDE). Mobile devices will also download their own separate high resolution almanac and ionospheric data over the internet which is superior to the low data rate GPS almanac. It can also use known cell locations to approximate its position. Combined, this enables rapid (hot) signal lock immediately onto the correct satellite code & Doppler shift frequency, which is why your mobile gets a fix in 3 seconds, versus your car which takes minutes.

stevehawk 4y ago

high resolution gps already exists. lookup WAAS

NKosmatos 4y ago
https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System "Currently, WAAS satellite coverage is only available in North America"
- oritsnile 4y ago
  There is also the European version of this EGNOS, besides there also private Providers like TerraStar
jrockway 4y ago
WAAS is nice but dual-band receivers provide similar accuracy levels without needing to see that satellite. Ublox quotes on their ZED-F9P datasheet 1.5m accuracy for GPS+GLONASS+Galileo+BeiDou, increasing to 1m accuracy if using space-based augmentation (WAAS, EGNOSS, MSAS, GAGAN). Even without a SBAS, if you can do RTK, you can get 0.01m accuracy. (The corrections from a nearby reference station are even better than what you can get from a satellite.) RTK is probably more available than people think. My state offers a public network of continuously-operating reference stations; you can sign up for a free account and then do whatever RTK madness you desire. https://cors.dot.ny.gov/ https://cors.dot.ny.gov/ if you happen to be in New York. (I realize now that I really wanted to reply to the person complaining about not being in North America, but oh well, maybe they'll find this.)
- mindslight 4y ago
  But the state-run reference stations are generally too far away from you to get that sweet sweet 1cm accuracy... It's amazing what you can do with consumer-priced gear these days. I set up a Sparkfun ZED-F9P breakout board as a fixed beacon on my roof, and then their "RTK Facet" as the rover to do precise measurements to create a map. I could have done the basic thing I needed to by hiring a surveyor or eyeballing things with a tape measure, but this is much more general. The GNSS software world seems to be a mess though, ripe for a paradigm shift. For example, QGIS seems to be based on flat projections with transformations rather than 3d-native - from what I can tell, QGIS seems to consider the "degree" to be a unit of length measurement! This leads to ridiculous things like being able to accidentally measure a nonsensical "cartesian" distance between two points that differs from the actual distance by a factor dependent on latitude. I've still got to tidy up my own pipeline that lets me do things like turn N (point, distance) samples into a single point. I would have thought that type of operation would be common, but thinking about how surveyors work I guess they're usually locating points optically, rather than trying to position a GPS receiver at the point to be measured.

KaiserPro 4y ago

> Starlink could charge a massive premium for high resolution GPS. but then they'd have to make it reliable. We are also not sure how much more (if at all) accurate it is. sure the bandwidth of the downlink is much higher, and louder than GPS, but the accuracy of the clocks on the satellites is much less. More importantly they are not characterised, so we arn't sure how much they drift due to temperature (both from sun and other effects.) depending on the navigation type, visual positioning might be better/faster/more accurate. For "military" purposes, silent autonomous navigation without radio sensors is pretty appealing. Using satellite imagery, its perfectly possible to make an accurate, robust visual navigation system for urban areas, "VPS"s are far quicker and more accurate, but require network access to work practically.