Bernese Gnss Today

Bernese GNSS

1. The Genesis: Solving the "Impossible" Problem

To understand the significance of Bernese, one must rewind to the late 1980s and early 1990s. The Global Positioning System (GPS) was in its infancy. While the U.S. military had access to the precise Precise Positioning Service (PPS), civilian scientists were relegated to the Standard Positioning Service (SPS), which was intentionally degraded by a policy known as Selective Availability (SA). This limited civilian accuracy to roughly 100 meters.

Scientists at the University of Bern, led by figures like Prof. Gerhard Beutler, refused to accept this limitation. They realized that the key to precision wasn't just better hardware, but better mathematics.

The Bernese software was born out of a necessity to extract the maximum amount of information from the carrier phase signal (the raw radio wave emitted by the satellite) rather than relying solely on the coded navigation message. By treating the receiver and the satellite as components of a single, massive mathematical system, Bernese allowed researchers to overcome the intentional noise of Selective Availability. Long before the U.S. government turned off SA in the year 2000, Bernese users were achieving centimeter-level accuracy. bernese gnss

D. Low Earth Orbiter Precise Orbit Determination

Satellites like Sentinel-6 (ocean altimetry) and GRACE-FO (gravity recovery) require orbit knowledge to within 2 cm radially. Bernese is a standard tool at ESA and NASA for processing on-board GPS data from LEO satellites.

Typical Data Flow

  1. Download RINEX data from your receivers and nearby IGS stations.
  2. Obtain precise orbits from CODE (Center for Orbit Determination in Europe) or IGS.
  3. Run preprocessing (screening for cycle slips and outliers).
  4. Compute station coordinates (using either double-difference network solutions or PPP).
  5. Perform quality control by analyzing residuals and repeatability.

2. National Reference Frames

Every modern country maintains a national spatial reference system (e.g., NAD83 in North America, ETRS89 in Europe). Bernese GNSS is the standard tool for defining and maintaining these frames by processing data from continuously operating reference stations (CORS). Bernese GNSS 1

3. The Paradigm: The Double Difference

At the mathematical heart of Bernese lies the concept of the Double Difference.

Imagine two receivers on the ground tracking two satellites simultaneously. By differencing the measurements between the satellites and the receivers, Bernese can mathematically eliminate the clock errors of both the satellites and the receivers. Typical Data Flow

This is a revolutionary concept. Atomic clocks on satellites drift, and quartz clocks in receivers are cheap and unstable. By using the Double Difference method, Bernese renders the absolute time of the clocks irrelevant, focusing entirely on the geometry of the baseline between the receivers. This allows cheap receiver hardware to perform with the precision of laboratory instruments, provided the data is processed through the Bernese engine.