-Note that the only mandatory parameters in this file are the 'Station' parameters in the first column, each standing for an observation stream's mountpoint or the 4-character station ID of a RINEX filename. The following shows further valid examples for records of a 'Coordinates file'.
+Note again that the only mandatory parameters in this file are the 'Station' parameters in the first column, each standing for an observation stream's mountpoint or the 4-character station ID of a RINEX filename. The following shows further valid examples for records of a 'Coordinates file'.
@@ -3266,12 +3280,13 @@
Depending on selected processing options you find 'GPS Time' stamps (yyyy-mm-dd_hh:mm:ss.sss) followed by
-with 'z' being the zenith distance to the involved satellite can be applied instead of the simple weight function 'P = 1'.
+with 'z' being the zenith distance to the involved satellite can be applied instead of the simple weight function 'P = 1' independent from satellite elevation angles.
@@ -3572,5 +3587,5 @@
-This so-called Quick-Start option allows the PPP solutions to rapidly converge after startup. It requires that the antenna remains unmoved on the known position throughout the defined period. A value of '60' seconds is likely to be an appropriate choice for 'Seeding'. Default is an empty option field, meaning that you do not want BNC to start in Quick-Start mode.
+This so-called Quick-Start option allows the PPP solutions to rapidly converge after startup. It requires that the antenna remains unmoved on the known position throughout the defined period. A value of '60' seconds is likely to be an appropriate choice for 'Seeding'. Default is an empty option field, meaning that you do not want BNC to start in Quick-Start mode.
You may need to create your own reference coordinate beforehand through running BNC for an hour in normal mode before applying the 'Seeding' option. Do not forget to introduce realistic North/East/Up sigmas under panel 'PPP (2)' corresponding to the coordinate's precision.
@@ -3578,5 +3593,5 @@
-'Seeding' has also a function for bridging gaps in PPP solutions from failures caused e.g. by longer lasting outages. Should the time span between two consecutive solutions exceed the limit of 60 seconds (maximum solution gap, hard-wired), the algorithm fixes the latest derived coordinate for a period of 'Seeding' seconds. This option avoids time-consuming reconvergences and makes especially sense for stationarily operated receivers where convergence can be enforced because a good approximation for the receiver position is known.
+'Seeding' has also a function for bridging gaps in PPP solutions from failures caused e.g. by longer lasting outages. Should the time span between two consecutive solutions exceed the limit of 60 seconds (maximum solution gap, hard-wired), the algorithm fixes the latest derived coordinate for a period of 'Seeding' seconds. This option avoids time-consuming reconvergences and makes especially sense for stationary operated receivers where convergence can be enforced because a good approximation for the receiver position is known.
@@ -3598,5 +3613,5 @@
-Note that a PPP dicplacements time series makes only sense for a stationarily operated receiver.
+Note that a PPP dicplacements time series makes only sense for a stationary operated receiver.
@@ -3653,9 +3668,11 @@
-BNC allows processing several orbit and clock correction streams in real-time to produce, encode, upload and save a combination of Broadcast Corrections from various providers. All corrections must refer to satellite Antenna Phase Centers (APC). It is so far only the satellite clock corrections which are combined while orbit corrections in the combination product as well as the product update rates are just taken over from one of the incoming Broadcast Correction streams. Combining only clock corrections using a fixed orbit reference imposes the potential to introduce some analysis inconsistencies. We may therefore eventually consider improvements on this approach. The clock combination can be based either on a plain 'Single-Epoch' or on a Kalman 'Filter' approach.
-
-
-In the Kalman Filter approach, satellite clocks estimated by individual Analyses Centers (ACs) are used as pseudo observations within the adjustment process. Each observation is modeled as a linear function (actually a simple sum) of three estimated parameters: AC specific offset, satellite specific offset common to all ACs, and the actual satellite clock correction, which represents the result of the combination. These three parameter types differ in their statistical properties. The satellite clock offsets are assumed to be static parameters while AC specific and satellite specific offsets are stochastic parameters with appropriate white noise.
- The solution is regularized by a set of minimal constraints. After a change of one of the three values 'SSR Provider ID', 'SSR Solution ID', or 'IOD SSR', the satellite clock offsets belonging to the corresponding analysis center are reset in the adjustment.
+BNC allows processing several orbit and clock correction streams in real-time to produce, encode, upload and save a combination of Broadcast Corrections from various providers. All corrections must refer to satellite Antenna Phase Centers (APC). It is so far only the satellite clock corrections which are combined by BNC while orbit corrections in the combination product as well as product update rates are just taken over from one of the incoming Broadcast Correction streams. Combining only clock corrections using a fixed orbit reference imposes the potential to introduce some analysis inconsistencies. We may therefore eventually consider improvements on this approach. The clock combination can be based either on a plain 'Single-Epoch' or on a Kalman 'Filter' approach.
+
+
+In the Kalman Filter approach, satellite clocks estimated by individual Analyses Centers (ACs) are used as pseudo observations within the adjustment process. Each observation is modeled as a linear function (actually a simple sum) of three estimated parameters: AC specific offset, satellite specific offset common to all ACs, and the actual satellite clock correction, which represents the result of the combination. These three parameter types differ in their statistical properties. The satellite clock offsets are assumed to be static parameters while AC specific and satellite specific offsets are stochastic parameters affected by white noise.
+
+
+The solution is regularized by a set of minimal constraints. In case of a change of the 'SSR Provider ID', 'SSR Solution ID', or 'IOD SSR' (see section 'Upload Corrections'), the satellite clock offsets belonging to the corresponding analysis center are reset in the adjustment.
@@ -3665,5 +3682,5 @@
In view of IGS real-time products, the 'Combine Corrections' functionality has been integrated in BNC (Weber and Mervart 2010) because
-- The software with its Graphic User Interface and wide range of supported Operating Systems represents a perfect platform to process many Broadcast Correction streams in parallel;
+- The software with its Graphic User Interface and range of supported Operating Systems represents a perfect platform to process many Broadcast Correction streams in parallel;
- Outages of single AC product streams can be mitigated through merging several incoming streams into a combined product;
- Generating a combination product from several AC products allows detecting and rejecting outliers;
@@ -3671,5 +3688,5 @@
- An individual AC could prefer to disseminate a stream combined from primary and backup IT resources to reduce outages;
- It enables a BNC PPP user to follow his own preference in combining streams from individual ACs for Precise Point Positioning;
-- It allows an instantaneous quality control of the combination process not only in the time domain but also in the space domain; this can be done through direct application of the combined stream in a PPP solution even without prior upload to an Ntrip Broadcaster;
+- It allows an instantaneous quality control of the combination process not only in the time domain but also in the space domain; this can be done by direct application of the combined stream in a PPP solution even without prior upload to an Ntrip Broadcaster;
- It provides the means to output SP3 and Clock RINEX files containing precise orbit and clock information for further processing using other tools than BNC.
@@ -3705,38 +3722,33 @@
-Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections' mountpoint in the PPP (1) panel.
-
-
-
-
-Hit the 'Add Row' button, double click on the 'Mountpoint' field, enter a Broadcast Correction mountpoint from the 'Streams' section and hit Enter. Then double click on the 'AC Name' field to enter your choice of an abbreviation for the Analysis Center (AC) providing the Antenna Phase Center (APC) related stream. Finally, double click on the 'Weight' field to enter a weight to be applied to this stream in the combination.
-
-
-The sequence of entries in the 'Combine Corrections' table is not of importance. Note that the orbit information in the final combination stream is just copied from one of the incoming streams. The stream used for providing the orbits may vary over time: if the orbit-providing stream has an outage then BNC switches to the next remaining stream for getting hold of the orbit information.
-
-It is possible to specify only one Broadcast Ephemeris correction stream in the 'Combine Corrections' table. Instead of combining corrections from several sources, BNC will then merge the single corrections stream with Broadcast Ephemeris to save results in SP3 and/or Clock RINEX format when specified accordingly under the 'Upload Corrections' panel. Note that in such a BNC application you must not pull more than one Broadcast Ephemeris correction stream even if a second stream would provide the same corrections from a backup caster.
-
-
-Default is an empty 'Combine Corrections' table meaning that you do not want BNC to combine orbit and clock correction streams.
-
-
-
-
-Hit 'Add Row' button to add another row to the 'Combine Corrections' table or hit the 'Delete' button to delete the highlighted row(s).
-
-
-
-The following screenshots describe an example setup of BNC when combining Broadcast Correction streams and uploading them to an Ntrip Broadcaster. Note that this application requires specifying options under panels 'Combine Corrections' and 'Upload Corrections'. The example uses the combination product to simultaneously carry out an 'INTERNAL' PPP solution, which allows monitoring the quality of the combination product in the space domain.
-
-
-
+The following screenshot shows an example setup of BNC when combining Broadcast Correction streams CLK11, CLK21, CLK91, and CLK80.
+
+
Figure 28: BNC combining Broadcast Correction streams
-
-Figure 29: BNC uploading the combined Broadcast Correction stream
-
+
+Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections stream' in the PPP (1) panel. The following example combines correction streams IGS01 and IGS02 and simultaneously carries out a PPP solution with observations from stream FFMJ1 to allow monitoring the quality of the combination product in the space domain.
+
-Figure 30: 'INTERNAL' PPP with BNC using combined Broadcast Correction stream
+Figure 29: 'INTERNAL' PPP with BNC using a combination of Broadcast Corrections
+
+
+
+Hit the 'Add Row' button, double click on the 'Mountpoint' field, enter a Broadcast Correction mountpoint from the 'Streams' section and hit Enter. Then double click on the 'AC Name' field to enter your choice of an abbreviation for the Analysis Center (AC) providing the Antenna Phase Center (APC) related correction stream. Finally, double click on the 'Weight' field to enter a weight to be applied to this stream in the combination.
+
+
+The sequence of entries in the 'Combine Corrections' table is not of importance. Note that the orbit information in the final combination stream is just copied from one of the incoming streams. The stream used for providing the orbits may vary over time: if the orbit-providing stream has an outage then BNC switches to the next remaining stream for getting hold of the orbit information.
+
+It is possible to specify only one Broadcast Ephemeris correction stream in the 'Combine Corrections' table. Instead of combining corrections from several sources, BNC will then merge the single corrections stream with Broadcast Ephemeris to allow saving results in SP3 and/or Clock RINEX format when specified accordingly under the 'Upload Corrections' panel. Note that in such a BNC application you must not pull more than one Broadcast Ephemeris correction stream even if a second stream would provide the same corrections from a backup caster.
+
+
+Default is an empty 'Combine Corrections' table, meaning that you do not want BNC to combine orbit and clock correction streams.
+
+
+
+
+Hit 'Add Row' button to add another row to the 'Combine Corrections' table or hit the 'Delete' button to delete the highlighted row(s).
+
@@ -3761,5 +3773,5 @@
-BNC can upload streams carrying orbit and clock corrections to Broadcast Ephemeris in radial, along-track and cross-track components if they are
+BNC can upload streams carrying orbit and clock corrections to Broadcast Ephemeris in radial, along-track and out-of-plane components if they are
-
either generated by BNC as a combination of several individual Broadcast Correction streams coming from an number of real-time Analysis Centers (ACs), see section 'Combine Corrections',
@@ -3776,5 +3788,5 @@
- Calculate XYZ coordinates from Broadcast Ephemeris orbits.
- Calculate differences dX,dY,dZ between Broadcast Ephemeris and IGS08 orbits.
-- Transform these differences into radial, along-track and cross-track corrections to Broadcast Ephemeris orbits.
+- Transform these differences into radial, along-track and out-of-plane corrections to Broadcast Ephemeris orbits.
- Calculate corrections to Broadcast Ephemeris clocks as differences between Broadcast Ephemeris clocks and IGS08 clocks.
- Encode Broadcast Ephemeris orbit and clock corrections in RTCM Version 3 format.
@@ -3873,5 +3885,9 @@
-When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt = -2 (R * V) / c^2 where R *V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
+When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as
+
+ dt = -2 (R * V) / c2
+
+where R *V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
@@ -4070,5 +4086,5 @@
-Figure 31: Setting BNC's Custom Transformation Parameters window, example for 'ITRF2008->GDA94'
+Figure 30: Setting BNC's Custom Transformation Parameters window, example for 'ITRF2008->GDA94'
@@ -4117,13 +4133,23 @@
-
+
+
+When applying Broadcast Ephemeris corrections in a PPP algorithm or in a combination of several correction streams, it is important for the client software to receive information on the continuity of discontinuity of the stream contents. Here you can specify three ID's to describe the contents of your Broadcast Ephemeris correction stream when it is uploaded.
+
+- A 'SSR Provider ID' is issued by RTCM SC-104 on request to identify a SSR service (see e.g. http://software.rtcm-ntrip.org/wiki/SSRProvider). This ID is globally unique. Values vary in the range of 0-65535. Values in the range of 0-255 are reserved for experimental services.
+- A provider may generate several Broadcast Ephemeris correction streams with different contents. The 'SSR Solution ID' indicates different SSR services of one SSR provider. Values vary in the range of 0-15.
+- A change of the 'IOD SSR' is used to indicate a change in the SSR generating configuration, which may be relevant for the rover. Values vary in the range of 0-15.
+
+
+
+
Select the length of Clock RINEX files and SP3 Orbit files. The default value is 1 day.
-
+
BNC requires an orbit corrections sampling interval for the stream to be uploaded and sampling intervals for SP3 and Clock RINEX files. The outgoing stream's clock correction sampling interval follows that of incoming corrections and is therefore nothing to be specified here.
-
+
Select the stream's orbit correction sampling interval in seconds. A value of 60 sec may be appropriate.
A value of zero '0' tells BNC to upload all orbit correction samples coming in from the real-time GNSS engine along with the clock correction samples to produce combined orbit and clock corrections to Broadcast Ephemeris (1060 for GPS, 1066 for GLONASS).
@@ -4156,23 +4182,28 @@
Note that only when specifying a value of zero '0' (default) for 'Sampling Orb', BNC produces combined orbit and clock correction messages.
-
+
Select the SP3 orbit file sampling interval in minutes. A value of 15 min may be appropriate. A value of zero '0' tells BNC to store all available samples into SP3 orbit files.
-
+
Select the Clock RINEX file sampling interval in seconds. A value of 10 sec may be appropriate. A value of zero '0' tells BNC to store all available samples into Clock RINEX files.
-
+
Hit 'Custom Trafo' to specify your own 14 parameter Helmert Transformation instead of selecting a predefined transformation through 'System' button.
-
-The following screenshot shows the encoding and uploading of a stream of precise orbits and clocks coming from a real-time engine in 'RTNET' ASCII format. The stream is uploaded to Ntrip Broadcaster 'products.igs-ip.net'. It is referred to APC and IGS08. Uploaded data are locally saved in SP3 and Clock RINEX format. The SSR Provider ID is set to 3. The SSR Solution ID and the Issue of Data SSR are set to 1. Required Broadcast Ephemeris are received via stream 'RTCM3EPH'.
+
+
+IGS provides a file containing absolute phase center variations for GNSS satellite and receiver antennas in ANTEX format. Entering the full path to such an ANTEX file is required here for referring the SP3 file content to the satellite's Center of Mass (CoM). If you do not specify an ANTEX file, the SP3 file will contain orbit information which is referred to Antenna Phase Center (APC) instead of CoM.
+
+
+The following screenshot shows the encoding and uploading of a stream of precise orbits and clocks coming from a real-time network engine in 'RTNET' ASCII format. The stream is uploaded to Ntrip Broadcaster 'products.igs-ip.net'. It is referred to APC and IGS08. Uploaded data are locally saved in SP3 and Clock RINEX format. The SSR Provider ID is set to 3. The SSR Solution ID and the Issue of Data SSR are set to 1. Required Broadcast Ephemeris are received via stream 'RTCM3EPH'.
-Figure 32: BNC producing Broadcast Corrections from incoming precise orbits and clocks and uploading them to an Ntrip Broadcaster
-
-
-
-IGS provides a file containing absolute phase center variations for GNSS satellite and receiver antennas in ANTEX format. Entering the full path to such an ANTEX file is required here for referring the SP3 file content to the satellite's Center of Mass (CoM). If you do not specify an ANTEX file, the SP3 file will contain orbit information which is referred to Antenna Phase Center (APC) instead of CoM.
-
+Figure 31: BNC producing Broadcast Corrections from incoming precise orbits and clocks and uploading them to an Ntrip Broadcaster
+
+The following screenshot shows the encoding and uploading of several Broadcast Ephemeris correction streams combined from streams CLK11, CLK21, CLK80, and CLK91. Combined streams are uploaded to different Ntrip Broadcasters and referred to different reference systems. One of the uploaded streams is locally saved in SP3 and Clock RINEX format. Different SSR Provider IDs, SSR Solution IDs and Issue of Data IDs are specified. Required Broadcast Ephemeris are received via stream 'RTCM3EPH'.
+
+
+Figure 32: BNC uploading a combined Broadcast Correction stream
+