The following abbreviations are used throughout this manual: R&S®SMBV100B is abbreviated as R&S SMBVB, R&S®WinIQSIM2
is abbreviated as R&S WinIQSIM2; the license types 02/03/07/11/12/13/16 are abbreviated as xx.
TM
ContentsSatellite Navigation
Contents
1Welcome to the GNSS options............................................................. 9
The R&S SMBV100B-K44/-K66/-K94/-K97/-K98/-K106/-K107/-K108/-K109/-K122/K132/-K133/-K134/-K135/-K136/-K137 are firmware applications that add functionality
to generate signals in accordance with GPS, Galileo, GLONASS, NavIC, QZSS and
COMPASS/BeiDou navigation systems and SBAS augmentation systems.
This user manual contains a description of the functionality that the application provides, including remote control operation.
All functions not discussed in this manual are the same as in the base unit and are
described in the R&S SMBV100B user manual. The latest version is available at:
www.rohde-schwarz.com/manual/SMBV100B
Installation
You can find detailed installation instructions in the delivery of the option or in the
R&S SMBV100B service manual.
●Notes on screenshots............................................................................................. 13
1.1Key features
The global navigation satellite system (GNSS) solution for the R&S SMBV100B is suitable for R&D lab tests or production tests. Supported are all possible scenarios, from
simple setups with individual satellites all the way to flexible scenarios generated in
real time.
Real-time scenarios offer simulation of up to several hundred satellites for navigation
systems GPS, Galileo, GLONASS, BeiDou, NavIC and QZSS depending on the installed options.
Key features
The GNSS options key features are:
●
Support of multiple GNSS and regional navigation satellite systems (RNSS) and
signals including mixed constellations (Table 1-1)
●
Support of satellite-based augmentation systems (SBAS) and signals including
mixed constellations (Table 1-2)
●
Configuring the state of a particular signal component individually
●
Real-time simulation of realistic mixed constellations and unlimited simulation time
●
Flexible scenario generation including moving scenarios, dynamic power control
and atmospheric modeling
9User Manual 1178.9403.02 ─ 07
Welcome to the GNSS optionsSatellite Navigation
Key features
●
Configuration of realistic user environments, including obscuration and multipath,
antenna characteristics and vehicle attitude
●
Navigation test mode for satellite constellation simulation, position fixing and time
to first fix (TTFF) testing
●
Tracking test mode for signal acquisition and tracking tests
●
Single satellite per system test mode for production tests
●
Simulation of orbit perturbations and pseudorange errors
●
Support of ranging, correction and integrity services for SBAS
●
Configuration suitable for basic receiver testing using signals with zero, constant or
varying Doppler profiles
●
Common configuration of multi-frequency GNSS scenarios
●
Support of assisted GNSS test scenarios, including generation of assistance data
for GPS, Galileo, GLONASS and BeiDou
●
Logging of user motion and satellite-related parameters
●
Real-time external trajectory feed for hardware in the loop (HIL) applications
●
High signal dynamics, simulation of spinning vehicles to support aerospace and
defense applications
Table 1-1: Supported GNSS/RNSS, frequency bands and signals
GNSS/RNSSL1 bandL2 bandL5 band
GPSC/A, PC/A, P, L2CL5
GalileoE1E6E5a, E5b
GLONASSC/AC/A-
BeiDouB1I, B1CB3IB2I, B2a
QZSSC/AL2CL5
NavIC--SPS
Table 1-2: Supported SBAS, frequency bands and signals
SBASL1 bandL2 bandL5 band
EGNOSC/A-
WAASC/A-
MSASC/A--
GAGANC/A--
1)
SBAS "Exp L5" signals are for experimental use only and do not comply with SBAS
Exp L5
Exp L5
1)
1)
interface control document (ICD) specifications, see also Table 2-10.
10User Manual 1178.9403.02 ─ 07
1.2Accessing the GNSS dialog
To open the dialog with GNSS settings
► In the block diagram of the R&S SMBV100B, select "Baseband > GNSS".
A dialog box opens that displays the provided general settings.
The signal generation is not started immediately. To start signal generation with the
default settings, select "State > On".
1.3What's new
This manual describes firmware version FW 5.00.044.xx and later of the
R&S®SMBV100B.
Compared to the previous version, it provides the new features listed below:
●
Real-time kinematics (RTK) simulation of one GNSS receiver and up to two RTK
reference stations, see Chapter 11, "Real-time kinematics", on page 150.
●
GPS L1C signal generation, see "Signals"on page 66.
●
Additional file extensions added for RINEX 3.x navigation file format, see
Table 15-2.
●
Additional file extensions for satellites constellation files, see Table 20-1.
●
Antenna position top view and side view added, see "To add an antenna and dis-
play the antenna pattern on a 3D view"on page 117.
Welcome to the GNSS optionsSatellite Navigation
Documentation overview
1.4Documentation overview
This section provides an overview of the R&S SMBV100B user documentation. Unless
specified otherwise, you find the documents on the R&S SMBV100B product page at:
www.rohde-schwarz.com/manual/smbv100b
1.4.1Getting started manual
Introduces the R&S SMBV100B and describes how to set up and start working with the
product. Includes basic operations, typical measurement examples, and general information, e.g. safety instructions, etc. A printed version is delivered with the instrument.
11User Manual 1178.9403.02 ─ 07
1.4.2User manuals and help
Separate manuals for the base unit and the software options are provided for download:
●
Base unit manual
Contains the description of all instrument modes and functions. It also provides an
introduction to remote control, a complete description of the remote control commands with programming examples, and information on maintenance, instrument
interfaces and error messages. Includes the contents of the getting started manual.
●
Software option manual
Contains the description of the specific functions of an option. Basic information on
operating the R&S SMBV100B is not included.
The contents of the user manuals are available as help in the R&S SMBV100B. The
help offers quick, context-sensitive access to the complete information for the base unit
and the software options.
All user manuals are also available for download or for immediate display on the Internet.
Welcome to the GNSS optionsSatellite Navigation
Documentation overview
1.4.3Service manual
Describes the performance test for checking compliance with rated specifications, firmware update, troubleshooting, adjustments, installing options and maintenance.
The service manual is available for registered users on the global Rohde & Schwarz
information system (GLORIS):
https://gloris.rohde-schwarz.com
1.4.4Instrument security procedures
Deals with security issues when working with the R&S SMBV100B in secure areas. It
is available for download on the Internet.
1.4.5Printed safety instructions
Provides safety information in many languages. The printed document is delivered with
the product.
1.4.6Data sheets and brochures
The data sheet contains the technical specifications of the R&S SMBV100B. It also
lists the options and their order numbers and optional accessories.
The brochure provides an overview of the instrument and deals with the specific characteristics.
12User Manual 1178.9403.02 ─ 07
Welcome to the GNSS optionsSatellite Navigation
Notes on screenshots
See www.rohde-schwarz.com/brochure-datasheet/smbv100b
1.4.7Release notes and open source acknowledgment (OSA)
The release notes list new features, improvements and known issues of the current
firmware version, and describe the firmware installation.
The open-source acknowledgment document provides verbatim license texts of the
used open source software.
See www.rohde-schwarz.com/firmware/smbv100b
1.4.8Application notes, application cards, white papers, etc.
These documents deal with special applications or background information on particular topics.
See www.rohde-schwarz.com/application/smbv100b
1.5Scope
Tasks (in manual or remote operation) that are also performed in the base unit in the
same way are not described here.
In particular, it includes:
●
Managing settings and data lists, like saving and loading settings, creating and
accessing data lists, or accessing files in a particular directory.
●
Information on regular trigger, marker and clock signals and filter settings, if appropriate.
●
General instrument configuration, such as checking the system configuration, configuring networks and remote operation
●
Using the common status registers
For a description of such tasks, see the R&S SMBV100B user manual.
1.6Notes on screenshots
When describing the functions of the product, we use sample screenshots. These
screenshots are meant to illustrate as many as possible of the provided functions and
possible interdependencies between parameters. The shown values may not represent
realistic usage scenarios.
13User Manual 1178.9403.02 ─ 07
Welcome to the GNSS optionsSatellite Navigation
Notes on screenshots
The screenshots usually show a fully equipped product, that is: with all options installed. Thus, some functions shown in the screenshots may not be available in your particular product configuration.
14User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
Required options
2About the GNSS options
Global navigation satellite system (GNSS) employs the radio signals of several navigation standards, like GPS, Galileo, GLONASS and BeiDou and NavIC. For several
years, GPS used to be the only standard available for civilian navigation through its
C/A civilian code.
Nowadays, the GNSS signals and systems are undergoing fast development, some
systems are getting modernized and some are new. In the foreseeable future, several
more GNSS satellites utilizing more signals and new frequencies are available.
The GNSS implementation in the R&S SMBV100B enables you to generate composite
signals of GNSS satellites, depending on the installed options. Signal generation is
performed in real time and thus not limited to a certain time period.
The following chapters provide background information on required options, basic
terms and principles in the context of GNSS signal generation. For detailed information
on the GNSS standards, see the corresponding specifications.
2.1Required options
The basic equipment layout for generating GNSS signals includes:
●
Base unit
●
Baseband real-time extension (R&SSMBVB-K520)
●
At least one basic or modernized GNSS option, see Table 2-1. The modernized
GNSS options do not require a basic GNSS option.
For production testing, use the option Single-Satellite GNSS instead of a GNSS
option, see Table 2-3.
●
Optional enhanced simulation capability options, see Table 2-2.
●
Optional enhanced simulation capacity options, see Table 2-3.
Table 2-1: GNSS system options
OptionDesignationRemark
R&S SMBVB-K44GPSC/A and P signals in L1 and L2 bands
R&S SMBVB-K66GalileoE1 OS, E6, E5a and E5b signals in L1, L2 and L5 bands
R&S SMBVB-K94GLONASSC/A signal in L1 and L2 bands
R&S SMBVB-K97NavIC/IRNSSSPS signal in L5 band
R&S SMBVB-K98Modernized GPSL1C, L2C and L5 signals in L1, L2 and L5 bands
R&S SMBVB-K107BeiDou/COMPASSB1I signal in L5 band
R&S SMBVB-K132Modernized BeiDouB1C, B3I and B2a signals in L1, L2 and L5 bands
15User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
Required options
Table 2-2: GNSS simulation capability options
OptionDesignationRemark
R&S SMBVB-K106SBAS/QZSSRequires R&S SMBVB-K44.
Augmentation system option using satellite-based and
regional navigation signals.
R&S SMBVB-K108Real world simulationSimulates real-world environments: Signal obscurations,
echoed and multipath effects, receiver antenna patterns
and body masks.
R&S SMBVB-K109Real-time interfacesEmulates a realistic environment of the DUT in real time
via the Hardware in the Loop test mode.
R&S SMBVB-K122Real-time kinematics
(RTK)
Table 2-3: GNSS simulation capacity options
OptionDesignationRemark
R&S SMBVB-K133Single-Satellite GNSSRequires no GNSS system option.
R&S SMBVB-K134Dual-frequency GNSSSimulation of 2 RF band signals
R&S SMBVB-K136Add 6 GNSS channelsInstallable up to 8 times
R&S SMBVB-K137Add 12 GNSS chan-
nels
Requires R&S SMBVB-K520.
Simulates RTK kinematics for up to two RTK reference
stations and one GNSS receiver.
Single satellite signal of a GNSS system suitable for production testing.
Simulation of 3 RF band signals
Installable up to 8 times
There is a limitation on the maximum number of satellite signals that can be simulated
simultaneously. For more information, see Chapter G, "Channel budget", on page 585.
The column "Licenses" lists the number of installed options.
To play back GNSS waveforms
You can generate signals via play-back of waveform files at the signal generator. To
create the waveform file using R&S WinIQSIM2, you do not need a specific option.
To play back the waveform file at the signal generator, you have two options:
●
Install the R&S WinIQSIM2 option of the digital standard, e.g. R&S SMBVB-K255
for playing LTE waveforms
●
If supported, install the real-time option of the digital standard, e.g. R&S SMBVBK55 for playing LTE waveforms
16User Manual 1178.9403.02 ─ 07
For more information, see data sheet.
2.2GNSS overview
This section provides an overiew on the GNSS including the following:
●
Power spectral density and center frequencies
●
Characteristics of the satellite constellation
●
Signal plan for each GNSS
The number of deployed satellites increases constantly. For the current deployment
status, see the official information of the GNSS providers.
The GNSS simulation capacity depends on installed options and the visibility state of
the individual satellite. For the number of satellites that can be present in the satellite
constellation, see Table 6-1.
About the GNSS optionsSatellite Navigation
GNSS overview
Figure 2-1: Power spectral density and center frequencies of most important GNSS signals
Red= GPS L1, L2 and L5 signals, details in GPS signal plan
Blue = Galileo E1, E5 and E6 signals, details in Galileo signal plan
Green = GLONASS G1, G2 and G3 signals, details in GLONASS signal plan
Yellow = BeiDou B1, B2 and B3 signals, details in BeiDou signal plan
GPS
The Global Positioning System (GPS) consists of several satellites circling the earth in
low orbits. The satellites transmit permanently information that can be used by the
receivers to calculate their current position (ephemeris) and about the orbits of all satellites (almanac). The 3D position of a receiver on the earth can be determined by carrying out delay measurements of at least four signals emitted by different satellites.
Being transmitted on a single carrier frequency, the signals of the individual satellites
can be distinguished by correlation (gold) codes. These ranging codes are used as
spreading codes for the navigation message which is transmitted at a rate of 50 bauds.
The C/A codes are used to provide standard positioning service (SPS), the P(Y) codes
to provide precise positioning service (PPS).
17User Manual 1178.9403.02 ─ 07
Table 2-4: GPS signal plan
Service nameC/AP(Y)L1CL2C
About the GNSS optionsSatellite Navigation
GNSS overview
1)
MCode
L5I, L5Q
Frequency bandL1L1
L2
Center frequency,
MHz
ModulationBPSK(1)BPSK(10)TMBOC
1)
M code signals are not supported with the GNSS firmware.
1575.421575.42
1227.6
L1L2L1
L2
1575.421227.61575.42
1227.6
BPSK(1)BOC(10,5)QPSK(10)
(6,1,1/11)
L5
1176.45
Galileo
Galileo is the European global navigation satellite system that provides global positioning service under civilian control. It is planed to be inter-operable with GPS and GLONASS and other global satellite navigation systems.
The fully deployed Galileo system consists of operational and spare satellites. Three
independent CDMA signals, named E5, E6 and E1, are permanently transmitted by all
Galileo satellites. The E5 signal is further subdivided into two signals denoted E5a and
E5b (see Figure 2-1). The Galileo system provides open service (OS), public regulated
service (PRS) to authorized, commercial service (CS) and search and rescue (SAR)
service.
Table 2-5: Galileo signal plan
Service nameE1 OS
PRS
1)
E5a OSE5b OSE6 CS
Frequency bandE1E1E6E5
Center frequency,
MHz
ModulationCBOC
1)
Galileo E1 PRS signal is not supported with the GNSS firmware.
1575.421575.421278.751176.451207.141278.75
(6,1,1/11)
BOC
(15,2.5)
BOC(10,5)AltBOC
(15,10)
E6
BPSK(5)
GLONASS
GLONASS is the Russian global navigation satellite system that uses 24 modernized
GLONASS satellites touring the globe.
Together with GPS, more GNSS satellites are provided, which improves the availability
and therefore the navigation performance in high urban areas.
Table 2-6: GLONASS signal plan
Service nameC/A
Frequency bandG1G2G1G2G3
1)
P
G3I , G3Q
1)
18User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
GNSS overview
Center frequency,
MHz
ModulationBPSK(0.5)
1)
G1 and G2 P code signals and G3I/Q signals are not supported in the GNSS firm-
1602 ±
k*0.5625
1246 ±
2)
k*0.5625
1602 ±
2)
k*0.5625
BPSK(5)
1246 ±
2)
k*0.5625
1202.025
2)
QPSK(10)
ware.
2)
k is the frequency number (FDMA) with -7 ≤ k ≤ 13.
BeiDou
The fully deployed BeiDou navigation satellite system (BDS) is a Chinese satellite navigation system. This navigation system is also referred as BeiDou-2.
The BDS is a global satellite navigation system with a constellation of satellites (COMPASS satellites) to cover the globe. The constellation includes geostationary orbit satellites (GEO) and non-geostationary satellites. The non-geostationary satllites comprise medium earth orbit satellites (MEO) and inclined geosynchronous orbit (IGSO).
The BDS uses frequency allocated in the B1, B2 and B3 bands providing open service
(OS) and authorized service (AS).
Table 2-7: BeiDou signal plan
SignalB1CB1IB2aB2IB3I
Frequency
band
Center frequency, MHz
ModulationBOC(1,1)
B1B1B2B2B3
1575.421561.0981176.451207.141268.52
QMBOC(6, 1, 4/33)
BPSK(2)BPSK(10)
BPSK(10)
BPSK(2)BPSK(10)
BeiDou B1Q, B2Q and B3Q AS signals are not supported in the GNSS firmware.
QZSS
The Quasi-Zenith satellite system (QZSS) is a regional space-based positioning system deployed in 2013.
In its final deployment stage, the QZSS uses a total number of three regional non-geostationary and highly inclined satellites and one geostationary orbit (GEO) satellite. The
QZSS does not aim to cover the globe but to increase the availability of GPS in Japan,
especially in the larger towns.
The QZSS uses signals that are similar to the GPS public signals.
QZSS L1C, SAIF and E6 LEX signals are not supported in the GNSS firmware.
NavIC
NavIC (Navigation Indian Constellation) is the indian navigation satellite system, formerly denoted IRNSS (Indian Regional Navigational Satellite System).
NavIC is a regional satellite navigation system with a constellation of satellites to cover
an area of 1500 km surrounding India (2016). The constellation includes geostationary
orbit (GEO) satellites and inclined geosynchronous orbit (IGSO) satellites.
The NavIC system uses frequencies allocated in the L5 and S bands providing special
positioning service (SPS) and precision service (PS).
Table 2-9: NavIC signal plan
SignalSPS
Frequency bandL5S
Center frequency, MHz1176.452491.75
ModulationBPSK(1)N/A
PS
1)
1)
NavIC PS signal is not supported in the GNSS firmware.
Assisted GNSS (A-GNSS)
Assisted GNSS (A-GNSS) was introduced to different mobile communication standards to reduce the time to first fix (TTFF) of a user equipment (UE) containing a GNSS
receiver. The reduction is achieved by transmitting information (assistance data) mainly
about the satellites directly from a base station to the UE.
For example, a standalone GPS receiver needs about 30 to 60 seconds for a first fix
and up to 12.5 minutes to get all information (almanac).
In A-GNSS "UE-based mode", the base station assists the UE by providing the complete navigation message along with a list of visible satellites and ephemeris data. In
addition to this information, the UE gets the location and the current time at the base
station. That speeds up both acquisition and navigation processes of the GPS receiver
and reduces TTFF to a few seconds.
In A-GNSS "UE assisted mode", the base station is even responsible for the calculation of the UE's exact location. The base station takes over the navigation based on the
raw measurements provided by the UE. Since the acquisition assistance data provided
by the base station already serves speeding up the acquisition process, the UE only
has to track the code and carrier phase.
20User Manual 1178.9403.02 ─ 07
2.3SBAS overview
Satellite-based augmentation systems (SBAS) use geostationary satellites (GEO) to
broadcast GNSS coarse integrity and wide area correction data (error estimations),
and ranging signal to augment the GNSS.
SBAS broadcast augmentation data in the GPS frequency band L1 using the C/A code
of GPS. For experimental use, the R&S SMBV100B provides modulation of SBAS L1
navigation message data in the GPS L5 band for SBAS systems EGNOS and WAAS.
Thus, the signal "Exp L5" is a pure copy of L1 data and does not comply with SBAS
interface control document (ICD) specifications.
Table 2-10: SBAS signal plan
SignalC/AExp L5
Frequency bandL1L5
Center frequency, MHz1575.421176.45
ModulationBPSK(1)N/A
About the GNSS optionsSatellite Navigation
GNSS components overview
The SBAS provides data for a maximum of 51 satellites. In the SBAS, the term pseudo
random number (PRN) is used instead of the term space vehicle (SV). There are 90
PRN numbers reserved for SBAS, where the numbering starts at 120.
Several SBAS systems are still in their development phase, like, for example, the
SDCM in Russia Federation, and GAGAN in India.
SBAS systems that are currently in operation argument the US GPS satellite navigation system, so that they are suitable, for example, for civil aviation navigation safety
needs. The following SBAS systems are supported by R&S SMBV100B:
●
EGNOS
EGNOS (European geostationary navigation overlay service) EGNOS is the European SBAS system
●
WAAS
WAAS (wide area augmentation system) is the SBAS system in United States
●
MSAS
MSAS (multi-functional satellite augmentation system ) is the SBAS system working in Japan. It uses the multi-functional transport satellites (MTSAT) and supports
differential GPS.
●
GAGAN
GAGAN (GPS aided geo augmented navigation system) is the SBAS implementation by the Indian government.
2.4GNSS components overview
The GNSS system comprises of three main components: the space segment, the
ground segment and the user segment.
21User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
GNSS components overview
Figure 2-2: GNSS system components (simplified)
1 = Space segment or satellites
2 = Ground segment or ground stations
3 = User segment or receivers
4 = Ephemeris (broadcasted satellites orbit and clock)
5 = Broadcasted navigation message
Space segment
The space segment consists of the satellites that orbit the earth on their individual
orbits. Satellites broadcast signals at specific frequency in the L band and spread by
predefined codes. For the GPS satellites using L1 frequency band, for instance, the
predefined codes are the coarse/acquisition (C/A) or the precision (P) codes.
The transmitted signal carries the navigation message, on which each satellite broadcasts its major characteristics, its clock offsets and precise orbit description, where the
latter is called ephemeris. The navigation message contains also satellites status
information, ionospheric and time-related parameters, UTC information and orbit data
with reduced accuracy for all other satellites, commonly referred as almanac.
Ground segment
The ground segment is a network of ground stations whose primary goal is to measure constantly the satellites’ location, altitude and velocity, and the satellites signals.
The ground stations also estimate the influence of the ionosphere. They calculate the
precise orbit (and orbit perturbation) parameters and clock drifts parameters of
each satellite. This corrected highly accurate information is regularly broadcasted back
to the satellites so that their navigation messages can be updated.
22User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
How are the GNSS components simulated?
User segment
Finally, the receiver decodes the navigation message (ephemeris and almanac)
broadcasted by the GNSS satellites, obtains information regarding the satellites orbit,
clock, health etc. and calculates the satellites coordinates. The receiver also measures
the signal propagation time (i.e. the pseudorange) of at least four satellites and estimates its own position.
2.5How are the GNSS components simulated?
In real life, the true satellite orbit can differ from the orbit information that the satellite
broadcasts.
In this implementation, the simulated orbit is the true orbit. Thus, the satellites motion
along their orbits, the clock they use and the current distance to each of them are referred to as simulated orbit, clock and pseudorange. They are set as retrieved from
the constellation data source and can be configured on a per satellite basis.
The navigation message of each of the satellites is per default identical to the simulated one. It is referred to as broadcasted navigation message, since it represents the
broadcasted satellite’s signal, see Figure 2-2. Per default, the broadcasted and the
simulated orbit and clock parameters match. Obviously, if the parameters in any of
those two groups are changed, a deviation between the sets is simulated.
The receiver is the device under test (DUT). In the simulation, the receiver is represented by its position, antenna configuration, environment, etc. The receiver is tested with
the GNSS it would receive in a real-world situation if placed in the specified conditions.
Simulation date, time and location
The R&S SMBV100B generates the signal for any simulation date and time, in the past
or in the future. The generated signal represents any location, on the earth or in the
space, for a static or moving receiver.
You have full control over the satellites’ constellation, the satellites signals and the navigation message of each satellite. Repeat measurement scenarios with same preconditions and vary the complexity or replay simulation events from the past.
For details, see:
●
Chapter 4, "Simulation time", on page 42
●
Chapter 5, "Receiver type and position", on page 48
●
Chapter 6, "Satellite constellation", on page 63
●
Chapter 7, "Space vehicle configuration", on page 75
Real-world scenarios through environmental effects
You can also simulate various different environmental conditions, like the effect of the
receiver’s antenna characteristic, vehicle movement, vehicle body mask, multipath
propagation, obstacles or the atmosphere.
For details, see Chapter 10, "Real-world environment", on page 108.
23User Manual 1178.9403.02 ─ 07
About the GNSS optionsSatellite Navigation
How are the GNSS components simulated?
Ionospheric effects
You can also simulate the effect of the atmospheric (ionospheric and tropospheric)
errors on the positioning accuracy.
For details, see "Tropospheric and ionospheric models"on page 168.
GNSS errors sources
Additional to the real-world and the ionosphere effects, you can simulate signal errors
by manipulating the navigation messages of the satellites. Signal errors have a direct
impact on the receiver’s positioning accuracy.
You can observe the effect of the following common error sources:
●
Orbit and orbit perturbation errors (ephemeris errors)
●
Satellite clock and time conversion errors
●
Pseudorange errors
For details, see Chapter 12, "Perturbations and errors simulation", on page 162.
Historical constellations and navigation data
You can also replay historical satellite constellations, by loading constellation files and
navigation data files for all GNSS systems supported in the GNSS firmware.
For details, see:
●
"Constellation data and navigation message file formats"on page 253
●
Chapter 16.1, "Import GNSS constellation and navigation message data settings",
on page 255
Correction data
You can also correct navigation data by loading SBAS corrections.
For details, see:
●
Chapter 13, "SBAS corrections", on page 208
●
Chapter 16.2, "Import SBAS constellation and correction data settings",
on page 257
24User Manual 1178.9403.02 ─ 07
Getting startedSatellite Navigation
Trying out the GNSS simulator
3Getting started
In its default configuration, the software generates GNSS signal that is sufficient for a
receiver to get a position fix. The simulated GNSS depends on the installed options.
For example, if R&S SMBV100B-K44 is installed, it is GPS C/A signal in the L1 band.
For all GNSS, the simulation starts on 19.02.2014 at 6 am UTC time and the satellite
constellation corresponds to a constellation, that is visible for a static receiver located
in Munich.
To simulate a defined configuration, you can load predefined assistance GNSS scenarios or load a user-defined scenario. The software applies the configuration automatically, you can change related settings afterwards. For example, try out the receiver
templates and configure a receiver, moving in a circle in New York.
●Trying out the GNSS simulator............................................................................... 25
2. Select, e.g., "General > Predefined Scenarios > Assisted GNSS > 3GPP2 >
3GPP2C.S0036 2.1.2 Moving".
See also Chapter E, "List of predefined test scenarios", on page 578.
3. Select "General > State > On".
26User Manual 1178.9403.02 ─ 07
Getting startedSatellite Navigation
Trying out the GNSS simulator
The summary information confirms the used scenario. Configured is a single GPS
system signal in the L1 frequency band.
4. To observe current satellite constellation and the trajectory of the moving receiver,
select "Simulation Monitor > Display > Receiver > Map View".
The "Simulation Monitor" shows the trajectory of the moving receiver.
5. To observe the preconfigured receiver settings, select "Simulation Monitor > Config".
6. In the "Simulation Configuration > Receiver" dialog, select "Position Configuration".
Observe the configuration.
27User Manual 1178.9403.02 ─ 07
7. In the block diagram, select "RF > On".
Getting startedSatellite Navigation
Trying out the GNSS simulator
The signal generation starts.
The frequency and level of the generated RF signal are configured automatically.
Further settings are not required.
For description of the related settings, see:
●Chapter 3.2, "General settings", on page 30
●Chapter 3.3, "Simulation monitor", on page 33
●Chapter 5, "Receiver type and position", on page 48