Several optional external datasets may be of interest. They provide corrections to main sources of errors that affect satellite signal measurements, such as orbit/clock errors and atmospheric delays, enabling high accuracy computation. They are used in conventional GNSS algorithms such as PPP (Precise Point Positioning) and RTK (Real Time Kinematic), which are able to produce centimeter-level positions for receivers with high quality antennas.
\nPPP utilizes precisely surveyed models to compensate errors in satellite orbit, clock, signal biases, ionospheric delay, tropospheric delay, etc. These models are sometimes referred to as State Space Representation (SSR) corrections. SSRs are available in but not limited to the following sources:
\nSwiftNav Skylark Corrections Service
\n-- Format: JSON converted from SwiftNav Binary Protocol (SBP, converters).
IGS Products: (need to register and then download from HTTPS)
\n-- Precise satellite orbit: Source, Format-SP3, Parser in C
\n-- Precise satellite clock: Source, Format-CLK, Parser in C
\n-- Precise ionosphere model: Source, Format-IONEX, Parser in C
\n-- Precise troposphere model: Source, Format-SINEX_TRO
RTK utilizes GNSS measurements from a nearby GNSS receiver (i.e. reference or base station). Because the rover (i.e. phone) and the reference station are measuring signals that are experiencing the same source of errors, RTK will subtract their measurements to cancel the common errors. The measurements from nearby reference stations are sometimes referred to as Observation Space Representation (OSR). Relevant OSR products can be found at:
\n-- Verizon Hyper Precise Location Service
\n-- SwiftNav Skylark Corrections Service
\n-- CORS
\n-- UNAVCO.
OSR is in the format of RINEX observation file. A RINEX parser can be found in RTKLIB (Windows binary, C source code).
\nThanks to @gymf123 for this information!
", "messages": [ { "id": "1304511", "postDate": "05/12/2021 17:00:22", "content": "Several optional external datasets may be of interest. They provide corrections to main sources of errors that affect satellite signal measurements, such as orbit/clock errors and atmospheric delays, enabling high accuracy computation. They are used in conventional GNSS algorithms such as PPP (Precise Point Positioning) and RTK (Real Time Kinematic), which are able to produce centimeter-level positions for receivers with high quality antennas.
\nPPP utilizes precisely surveyed models to compensate errors in satellite orbit, clock, signal biases, ionospheric delay, tropospheric delay, etc. These models are sometimes referred to as State Space Representation (SSR) corrections. SSRs are available in but not limited to the following sources:
\nSwiftNav Skylark Corrections Service
\n-- Format: JSON converted from SwiftNav Binary Protocol (SBP, converters).
IGS Products: (need to register and then download from HTTPS)
\n-- Precise satellite orbit: Source, Format-SP3, Parser in C
\n-- Precise satellite clock: Source, Format-CLK, Parser in C
\n-- Precise ionosphere model: Source, Format-IONEX, Parser in C
\n-- Precise troposphere model: Source, Format-SINEX_TRO
RTK utilizes GNSS measurements from a nearby GNSS receiver (i.e. reference or base station). Because the rover (i.e. phone) and the reference station are measuring signals that are experiencing the same source of errors, RTK will subtract their measurements to cancel the common errors. The measurements from nearby reference stations are sometimes referred to as Observation Space Representation (OSR). Relevant OSR products can be found at:
\n-- Verizon Hyper Precise Location Service
\n-- SwiftNav Skylark Corrections Service
\n-- CORS
\n-- UNAVCO.
OSR is in the format of RINEX observation file. A RINEX parser can be found in RTKLIB (Windows binary, C source code).
\nThanks to @gymf123 for this information!
", "rawMarkdown": "Several optional external datasets may be of interest. They provide corrections to main sources of errors that affect satellite signal measurements, such as orbit/clock errors and atmospheric delays, enabling high accuracy computation. They are used in conventional GNSS algorithms such as PPP (Precise Point Positioning) and RTK (Real Time Kinematic), which are able to produce centimeter-level positions for receivers with high quality antennas.\n\n**PPP** utilizes precisely surveyed models to compensate errors in satellite orbit, clock, signal biases, ionospheric delay, tropospheric delay, etc. These models are sometimes referred to as State Space Representation (SSR) corrections. SSRs are available in but not limited to the following sources:\n\n- [SwiftNav Skylark Corrections Service](https://www.swiftnav.com/google-smartphone-decimeter-challenge)\n -- Format: JSON converted from SwiftNav Binary Protocol ([SBP](https://www.swiftnav.com/latest/sbp-specification), [converters](https://github.com/swift-nav/libsbp)).\n\n\n- [IGS](https://www.igs.org/data-products-overview/) Products: (need to register and then download from HTTPS)\n -- Precise satellite orbit: [Source](https://www.igs.org/products/#precise_orbits), [Format-SP3](https://files.igs.org/pub/data/format/sp3c.txt), [Parser in C](https://github.com/tomojitakasu/RTKLIB/blob/71db0ffa0d9735697c6adfd06fdf766d0e5ce807/src/preceph.c)\n -- Precise satellite clock: [Source](https://www.igs.org/products/#clock_products), [Format-CLK](https://files.igs.org/pub/data/format/rinex_clock304.txt), [Parser in C](https://github.com/tomojitakasu/RTKLIB/blob/71db0ffa0d9735697c6adfd06fdf766d0e5ce807/src/rinex.c#L1338)\n -- Precise ionosphere model: [Source](https://www.igs.org/products/#ionospheric_products), [Format-IONEX](https://files.igs.org/pub/data/format/ionex1.pdf), [Parser in C](https://github.com/tomojitakasu/RTKLIB/blob/71db0ffa0d9735697c6adfd06fdf766d0e5ce807/src/ionex.c)\n -- Precise troposphere model: [Source](https://www.igs.org/products/#tropospheric_products), [Format-SINEX_TRO](https://files.igs.org/pub/data/format/sinex_tropo.txt)\n\n**RTK** utilizes GNSS measurements from a nearby GNSS receiver (i.e. reference or base station). Because the rover (i.e. phone) and the reference station are measuring signals that are experiencing the same source of errors, RTK will subtract their measurements to cancel the common errors. The measurements from nearby reference stations are sometimes referred to as Observation Space Representation (OSR). Relevant OSR products can be found at:\n\n-- [Verizon Hyper Precise Location Service](https://webscope.sandbox.yahoo.com/catalog.php?datatype=s&did=88)\n-- [SwiftNav Skylark Corrections Service](https://www.swiftnav.com/google-smartphone-decimeter-challenge)\n-- [CORS](https://geodesy.noaa.gov/CORS_Map/)\n-- [UNAVCO](https://www.unavco.org/instrumentation/networks/map/map.html#!/).\n\nOSR is in the format of RINEX observation file. A RINEX parser can be found in RTKLIB ([Windows binary](https://github.com/tomojitakasu/RTKLIB_bin/blob/rtklib_2.4.3/bin/rtkconv.exe), [C source code](https://github.com/tomojitakasu/RTKLIB/blob/rtklib_2.4.3/src/rinex.c)).\n\n\n\nThanks to @gymf123 for this information!", "votes": null }, { "id": "1342533", "postDate": "06/09/2021 14:34:27", "content": "@sohier is openstreetmap.org allowed as external data?
\nThank you!
@sohier is openstreetmap.org allowed as external data?
\nThank you!