ACCURACY STATEMENT
Bad Elf performs a variety of controlled tests on each product to test expected performance. Factors such as satellite geometry, multipath, environmental conditions are considered in our testing process. Statements of accuracy are in ideal, or near-ideal conditions, using best practices for field data collection.
GPS+PPP+SBAS ACCURACY
The GNSS Surveyor is capable of producing 1 meter CEP positional accuracy using GPS+PPP+SBAS. uBlox states that "PPP technology is made possible by stabilizing measurements of the distance between GNSS satellites and the receiver (pseudo-ranges) using carrier phase tracking. Additional accuracy is achieved from ionospheric correctional data received from satellite-based augmentation systems.
The image below represents a sample of what one can expect when using a GNSS Surveyor statically placed over a fixed location for 15 minutes. The center of the circle represents a know surveyed location that all of the measurements are calculated from. The requisite setup for this configuration includes:
- Greater than 6 satellites visible and locked
- SBAS signals being received and SBAS satellites locked
- A clear view of the sky above 15 degrees from the horizontal
Conditions and results: Avg NSV=7, CEP (0.52m), 2DRMS @95% (1.26m)
DGPS ACCURACY
The GNSS Surveyor is capable of producing 1 to 1.5 meters (CEP) positional accuracy using DGPS and RTCM 2.3. Differential corrections are Code-Phase GPS corrections and require a nearby reference station sending data over NTRIP.
The image below represents a sample of what one can expect when using a GNSS Surveyor statically placed over a fixed location for 15 minutes. The center of the circle represents a know surveyed location that all of the measurements are calculated from. The requisite setup for this configuration includes:
- Greater than 6 satellites visible and locked
- RTCM 2.3 feed active for at least 2 minutes
- A clear view of the sky above 15 degrees from the horizontal
Conditions and results: Avg NSV=7, CEP (1.09m), 2DRMS @95% (2.72m)
STAND ALONE ACCURACY
Accuracy in non-SBAS regions or using GLONASS instead of GPS is typically between 2-2.5m CEP for static occupations. Stand-alone performance is measured using the following parameters:
- Greater than 6 satellites visible and locked
- A clear view of the sky above 15 degrees from the horizontal
