solutions
Technology to collect data in terrain with GNSS
Aerial digital photogrammetry at SD CHomutov a.s.
Data in relational SQL databases

Technology to collect data in terrain with GNSS

GNSS instruments and accuracy

To understand the accuracy of measurement in TopoL we have to know something about GNSS accuracy.

First of all it depends on GNSS instrument, antenna etc. For example it is better to use external antenna, otherwise some satellites can be hidden by the body.

It also depends on number of sattelites and there distribution on sky. So it is important to check the PDOP and HDOP values.

DOP Value
bad distribution of GNSS sattelites

bad distribution of GNSS sattelites

good distribution of GNSS sattelites

good distribution of GNSS sattelites

Then it is important to use proper measuring method in TopoL. The most accurate is avaring for time interval. Longer time higher accuracy we have got.

There are also other sattelites like GLONASS, SBAS which are used to calculate the position.

Geographical information systems TopoL

TopoL xT

TopoL xT is general Geographic Information System software, which can be adjusted for applications in many areas. It allows the creation, maintenance, analyses and presentation of geographical data.

It enables direct connection of GNSS devices.

TopoL Mobile

TopoL Mobile is cheap and simple GIS solution for field data collection and navigation with GNSS. It runs under Windows CE, Windows Mobile operating system on Pocket PC.