Overview

XPLORA offers two modes for its users to choose from, depending on their demands and requirements:

• Core: The Core mode is capable of simulating arbitrary digital intermediate frequency (IF) GNSS signals. The sampled signal is available as digital file, which can be upconverted to RF and replayed by a proprietary hardware simulator. Additionally, several intermediate files, such as RINEX observation and navigation files as well as receiver trajectory files are produced for each computed scenario.
• Pro: The Pro mode, GNSS signals are immediately upconverted to RF and replayed by the IZT S1000 hardware antenna channels RF1 and RF2.

For a more detailed description of the two modes, see Modes.

Simulation Aspects

The software is capable of simulating different aspects of satellite navigation signals and these aspects directly refer to the main options available in the software.

GNSS Channels

Depending on the GNSS, several channels can be selected in the upper and lower L-Band to be simulated for a specific scenario.

Time Settings

The simulation time can be set from a variety of different time systems and is automatically transferred to other time-systems.

Satellites

• Satellite Orbits:
  Two options are available:

  1. Keplerian ephemeris parameters are used to compute the satellites orbits.
  2. Numeric Runge Kutta orbit integration which includes perturbing forces of sun and moon. The computation of the orbital Keplerian elements for the navigation messages is based on the integrated orbits.

• Satellite Clocks: Simulation of quadratic polynomials, randomized for each satellite and adding noise which is based on the different types of atomic clocks, and computed with respect to their spectral noise behavior (Allan deviation).

Atmosphere

• Ionosphere: Use of NeQuick, Klobuchar and IONEX models and the derivation of the navigation message parameters. Ionospheric activity can also be set by the sunspot number.
• Troposphere: Use of Galileo user reference, Global Temperature and Pressure 2 wet (GPT2w) and Hopfield troposphere model.

Receiver

• Receiver Trajectories: Definition of waypoints for receiver trajectories. The input is achieved through waypoints and calculation with first and second geodetic principals on the ellipsoid with arbitrary height profiles or via state propagation.
• Front-End settings: Detailed configuration of several Front-Ends possible.
• Antenna Pattern: Definition of elevation masks and antenna gain patterns where the signal attenuation is computed based on the geometric relation as well as the use of user-selected receiver antenna profiles and modelled satellite antenna patterns.
• Receiver-Clock: Simulation of local oscillator behaviour defined by its accuracy and stability.

Multipath

Simulation of multipath environments based on statistical models.

Interference

• Jamming: Simulation of an arbitrary number of interference signals with userdefined signal parameters (noise jamming and spectrum-matched jamming).
• Spoofing: Advanced spoofing signal simulation including modelling of imperfect alignment as well as multiple spoofing signal capabilities.

Signals

XPLORA is able to simulate global and regional navigation satellite system signals (see the list of available signals).