4 ms·

Remembering how ”easy” it is to navigate with such an arrow in GTA, I would expect this to fail in unimaginable ways. It could point at a river instead of the

Remembering how ”easy” it is to navigate with such an arrow in GTA, I would expect this to fail in unimaginable ways. It could point at a river instead of the bridge over it. It could point at an airport instead of the route around it. It could point at a cul-de-sac, a dangerous neighborhood, a construction site, etc.

scotty79 10mo ago
That depends on the implementation. It could use GPS and map to trace walkable path to destination and point the needle in the direction that you need to move towards to follow the path.
- simulator5g 10mo ago
  Except this doesn’t work on smartphones. Have you ever tried using GPS? It doesn’t understand what direction you’re facing unless you’re steadily moving forward.
  - scotty79 10mo ago
    It's because maps apps don't trust builtin compass. Which is reasonable since it fairly often loses calibration.
  - estimator7292 10mo ago
    That's because GPS is not directional. It's a positioning system. Direction can only be inferred as the difference between locations. GPS fundamentally has no way of determining your direction. It was never designed for anything other than giving you a single fixed 3D location on the Earth's surface.
    - robocat 10mo ago
      Rubbish: from first principles it is obvious that direction can be calculated. You are correct for phones, which have omnidirectional antennas that can't calculate direction (also built up areas with multipath would make direction finding difficult). Marine navigation systems are the most familiar example. Many boat GPS units advertise “GPS compass” or “true heading at zero speed.” . The antennas contain two GNSS elements, fixed a known distance apart, and the direction is found using phase comparison: they look at the tiny difference in arrival time of the same satellite signal at the two separate antennas. Either (a) don't answer if you don't know what you are talking about or better (b) double check your "facts" (using Google or AI) before answering.
      - scotty79 10mo ago
        You just basically confirmed what the previous commenter said. GPS is not directional. You need two of them placed some significant distance apart (think ship length, not smartphone length). When you have two points determined with high enough precision you obviously have a direction and even orientation. Your comment could have been just that. Useful information many people could find interesting. Instead you decided to sprinkle it with bile.
        robocat 10mo ago
        You are doubling down - I do find your misinformation to be interesting. Have a look at images of the antennas: https://duckduckgo.com/?q=%22GPS+compass%22+antenna&ia=images&iax=images https://duckduckgo.com/?q=%22GPS+compass%22+antenna&ia=image... I do apologize for liking brutal facts - I am an engineer type. I clicked the Furuno antenna since it looked sexy - blurb: SC-130 features a Tri-sensor antenna that provides a high system accuracy for the heading of your vessel [for Autopilot, berthing etcetera.]. 0.25°rms Fist principles: I think wavelength of L1 GPS frequency is about 0.2m - the same order as smartphone length. A ship length baseline using phase would need precise engineering and would not work for satellites absolutely perpendicular to the ship (making it less ideal). Calculating phase difference only needs a single satellite visible, so I would guess directionality can be precise in built up areas even where location is harder to fix. although I'm assuming multipath can be filtered out.
        scotty79 10mo ago
        SC-130 has distance between the antennas on the order of 1 meter and has three of them (which probably let's them be closer than in two antenna unit). If you test phase shift to one satelite you might get good accurancy for some directions and no accurancy at all for the orthogonal directions. So maybe not ship-length but still 1 meter sized device is way too large to put under the hood of a car let wlon in a smartphone. Again, GPS has no provisions for orientation detection. You can hack it with few antennas significantly spaced apart (thank you again for pointing out those solutions). I think it might be easier to detect location with GPS and orientation by testing phase shift to the closest cell tower (when on land). There's nothing in GPS system thst helps with determining orientation. And you still can't drop arrogance which gets tiresome.

scotty79 10mo ago

That depends on the implementation. It could use GPS and map to trace walkable path to destination and point the needle in the direction that you need to move towards to follow the path.

simulator5g 10mo ago
Except this doesn’t work on smartphones. Have you ever tried using GPS? It doesn’t understand what direction you’re facing unless you’re steadily moving forward.
- scotty79 10mo ago
  It's because maps apps don't trust builtin compass. Which is reasonable since it fairly often loses calibration.
- estimator7292 10mo ago
  That's because GPS is not directional. It's a positioning system. Direction can only be inferred as the difference between locations. GPS fundamentally has no way of determining your direction. It was never designed for anything other than giving you a single fixed 3D location on the Earth's surface.
  - robocat 10mo ago
    Rubbish: from first principles it is obvious that direction can be calculated. You are correct for phones, which have omnidirectional antennas that can't calculate direction (also built up areas with multipath would make direction finding difficult). Marine navigation systems are the most familiar example. Many boat GPS units advertise “GPS compass” or “true heading at zero speed.” . The antennas contain two GNSS elements, fixed a known distance apart, and the direction is found using phase comparison: they look at the tiny difference in arrival time of the same satellite signal at the two separate antennas. Either (a) don't answer if you don't know what you are talking about or better (b) double check your "facts" (using Google or AI) before answering.
    - scotty79 10mo ago
      You just basically confirmed what the previous commenter said. GPS is not directional. You need two of them placed some significant distance apart (think ship length, not smartphone length). When you have two points determined with high enough precision you obviously have a direction and even orientation. Your comment could have been just that. Useful information many people could find interesting. Instead you decided to sprinkle it with bile.
      - robocat 10mo ago
        You are doubling down - I do find your misinformation to be interesting. Have a look at images of the antennas: https://duckduckgo.com/?q=%22GPS+compass%22+antenna&ia=images&iax=images https://duckduckgo.com/?q=%22GPS+compass%22+antenna&ia=image... I do apologize for liking brutal facts - I am an engineer type. I clicked the Furuno antenna since it looked sexy - blurb: SC-130 features a Tri-sensor antenna that provides a high system accuracy for the heading of your vessel [for Autopilot, berthing etcetera.]. 0.25°rms Fist principles: I think wavelength of L1 GPS frequency is about 0.2m - the same order as smartphone length. A ship length baseline using phase would need precise engineering and would not work for satellites absolutely perpendicular to the ship (making it less ideal). Calculating phase difference only needs a single satellite visible, so I would guess directionality can be precise in built up areas even where location is harder to fix. although I'm assuming multipath can be filtered out.
        scotty79 10mo ago
        SC-130 has distance between the antennas on the order of 1 meter and has three of them (which probably let's them be closer than in two antenna unit). If you test phase shift to one satelite you might get good accurancy for some directions and no accurancy at all for the orthogonal directions. So maybe not ship-length but still 1 meter sized device is way too large to put under the hood of a car let wlon in a smartphone. Again, GPS has no provisions for orientation detection. You can hack it with few antennas significantly spaced apart (thank you again for pointing out those solutions). I think it might be easier to detect location with GPS and orientation by testing phase shift to the closest cell tower (when on land). There's nothing in GPS system thst helps with determining orientation. And you still can't drop arrogance which gets tiresome.