Class Grs
GNSS Range Residuals
Inherited Members
Namespace: NmeaParser.Messages
Assembly: NmeaParser.dll
Syntax
[NmeaMessageType("--GRS")]
public class Grs : NmeaMessage, IEquatable<NmeaMessage>, ITimestampedMessageRemarks
This sentence is used to support Receiver Autonomous Integrity Monitoring (RAIM). Range residuals can be computed in two ways for this process. The basic measurement integration cycle of most navigation filters generates a set of residuals and uses these to update the position state of the receiver.
These residuals can be reported with GRS, but because of the fact that these were used to generate the navigation solution they should be recomputed using the new solution in order to reflect the residuals for the position solution in the GGA or GNS sentence.
The MODE field should indicate which computation method was used. An integrity process that uses these range residuals would also require GGA or GNS, GSA, and GSV sentences to be sent.
If only GPS, or GLONASS, or Galileo, or BDS, or QZSS, or NavIC (IRNSS)is used for the reported position solution, the talker ID is GP, GL, GA, GB, GQ, GI respectively and the range residuals pertain to the individual system.
If GPS, GLONASS, Galileo, BDS, QZSS, NavIC (IRNSS) are combined to obtain the position solution multiple GRS sentences are produced, one with the GPS satellites, another with the GLONASS satellites, etc. Each of these GRS sentences shall have talker ID “GN”, to indicate that the satellites are used in a combined solution. The GNSS System ID data field identifies the specific satellite system. It is important to distinguish the residuals from those that would be produced by a GPS-only, GLONASS-only, etc. position solution. In general, the residuals for a combined solution will be different from the residual for a GPS-only, GLONASS-only, etc. solution.
When multiple GRS sentences are necessary, use of the NMEA TAG Block structure (§ 7) and the TAG Block Sentence-grouping Parameter (§ 7.9.3) reliably links the related sentences together over any transport medium.
When GRS sentences are provided with related GSA and/or GSV sentences, use of the NMEA TAG Block structure (§ 7) and the TAG Block Sentence-grouping Parameter (§ 7.9.3) reliably links the related (different sentence formatters) sentences together over any transport medium.
Constructors
| Name | Description |
|---|---|
| Grs(string, string[]) | Initializes a new instance of the Gbs class. |
Properties
| Name | Description |
|---|---|
| FixTime | UTC time of the GGA or GNS fix associated with this sentence |
| Mode | Residual calculation mode |
| Residuals | Range residuals in meters for satellites used in the navigation solution |
Applies
| Target | Versions |
|---|---|
| .NET Standard 2.0 | main, v3.0, v2.2, v2.1 |
| .NET | main, v3.0 |
| .NET Windows | main, v3.0 |
| .NET Android | main, v3.0 |
| .NET iOS | main, v3.0 |
| .NET Framework | main, v3.0, v2.2, v2.1 |
| UWP | main, v3.0, v2.2, v2.1 |
| Xamarin.Android | v2.2, v2.1 |
| Xamarin.iOS | v2.2, v2.1 |