Satellite navigation provides positioning, navigation and timing for people, vehicles and infrastructure. Receivers use precisely timed satellite signals and orbit information to estimate their position, velocity and clock offset.
PULSE follows the complete performance chain—from satellite orbits and clocks, through signals and atmospheric propagation, to service reliability and the solution delivered to the user.
A receiver compares signal arrival times with their transmission times to form pseudorange measurements. With signals from at least four suitably placed satellites, it can solve for three position coordinates and its clock offset. Carrier-phase measurements and correction services enable more precise solutions.
GPS, Galileo, GLONASS and BeiDou provide worldwide positioning and timing.
NavIC and QZSS bring region-focused geometry, signals and services.
SBAS broadcasts corrections and integrity information for defined service areas.
LEO-based services and demonstrators explore complementary geometry, signals and resilience.
Global and regional systems, augmentation services and emerging LEO-PNT capabilities contribute different signals, geometries and performance characteristics.
GPS · Galileo · GLONASS · BeiDou / BDS
Navigation satellites broadcast ranging signals, orbital parameters and timing information. Multi-constellation processing improves measurement diversity; performance still depends on geometry, environment and receiver configuration.
Position · Velocity · Time
NavIC / IRNSS · QZSS · KPS (in development)
Regional systems tailor coverage and orbital geometry to their service areas. NavIC serves India and its surroundings; QZSS supports the Asia–Oceania region, including Japan. Korea’s KPS is a developing regional programme.
Regional coverage · Geometry · Signals
EGNOS · WAAS · MSAS · GAGAN · KASS · BDSBAS · SDCM · SouthPAN · ANGA · AL-SBAS · NSAS · Pak-SBAS
SBAS uses reference stations, processing facilities and satellite broadcasts to support corrected navigation and integrity monitoring. This overview includes operational services and developing or proposed programmes; available capabilities and safety-of-life approvals vary by service.
SBAS L1 · SBAS L5 / DFMC · Service volumes
Celeste · Xona Pulsar · TrustPoint · Iridium PNT / STL
Low Earth orbit offers complementary dynamics and signal opportunities. Celeste is ESA’s in-orbit demonstrator; Pulsar and TrustPoint are developing PNT constellations. Iridium-based timing and location services provide a different LEO capability.
Multi-layer PNT · Timing · Resilience
Four complementary assessment levels connect the behaviour of the space segment and receiver to the accuracy, integrity, availability and continuity of the navigation service.
Compare orbit precision, clock synchronisation, ionospheric TEC and tropospheric delays with defined references.
Assess bandwidth, PSD, acquisition sensitivity, tracking errors and SBAS L1 / L5 processing against applicable requirements.
Map service volumes and assess accuracy, integrity, availability and continuity against explicit thresholds.
Analyse horizontal and vertical errors, convergence, fix availability and recovery for SPP, SBAS, PPP and RTK.
Assess the space segment and the environmental models that underpin the navigation solution.
Characterise the signal and its interaction with the acquisition, tracking and measurement chain.
Translate system and signal behaviour into service-volume performance against a defined operational requirement.
Evaluate the solution delivered to a receiver or application using explicit reference trajectories and processing assumptions.
Explore orbit and clock behaviour, atmospheric estimates, signal spectra, positioning errors and service integrity through a consistent set of analytical views.
Radial, along-track and cross-track orbit differences against a reference solution.
Satellite clock offset differences over time, expressed against a common reference.
Estimated and reference vertical TEC with an illustrative estimation envelope.
Estimated zenith total delay compared with a reference time series.
European service-volume assessment · PULSE modelled availability field.
East–north position errors and an illustrative 95% error ellipse.
Vertical position error versus protection level · PULSE modelled scenario.
Galileo E5 AltBOC(15,10): analytical component-envelope PSD, centred on 1191.795 MHz.
PULSE figures · Illustrative analyses and modelled scenarios. Galileo E5 PSD uses an analytical component-envelope approximation.
PULSE · Modelled availability scenario
Combine receiver measurements with IGS and analysis-centre products, physical models and the signal or service definitions applicable to the assessment.
RINEX observations and navigation messages, RTCM streams and receiver logs provide the measurements. IGS and MGEX products, including precise SP3 orbits and CLK clocks, support comparisons using defined time systems and reference frames.
ANTEX antenna models, DCB or Bias-SINEX signal biases, IONEX ionospheric maps and tropospheric products support consistent modelling. Track antenna reference points, phase centres, mapping functions and model conventions.
Use the relevant signal-in-space ICDs, SBAS L1 and L5 / DFMC definitions, service documents and applicable MOPS edition. Define test conditions and thresholds for each requirement; compliance assessment and equipment certification are distinct activities.
Retain station metadata, receiver configuration, cycle-slip checks, data gaps and correction ages. Version reference products and processing settings; document uncertainty, reference quality and evaluation intervals alongside the results.
Explore the PULSE toolbox, connect navigation results with observation and telecommunications, or tell us about your performance-assessment needs.