DFHRS - Namibia 2002

The computation of the DFHRS databases for Namibia and for the district or the capital Windhoek were performed in a cooperation project between the RaD project DFHRS at IAF/HSKA and African Geomatics (Pty), Ltd, Windhoek.

The computation of the DFHRS database for Namibia was part of the diploma-thesis of Armin Hoffmann and Stephan Tepper (2002) "Planung, Berechnung und Qualitätsanalyse der DFHBF_DB Namibia und Windhoek unter Einbindung zusätzlicher GPS-Messungen als Kooperationsprojekt zwischen African Geomatics und der University of Applied Sciences (FH) Karlsruhe sowie begleitende C++ Softwareentwicklungen" at the Faculty of Geomatics at HSKA. The computations were according to the DFHRS approach stage 1, formulas (2a-f). Due to the small amount of only 4 identical points (B,L,h|H) country-wide only 4 patches could be set up (fig.). The geoid-observations (2b) within the 4 patches were introduced with an accuracy of 0.3 m.

The fig. below shows the accuracy surface of the Namibian DFHRS version 1, resulting from the covariance matrix of the DFHRS parameters p of the adjustment (2a-f), see DFHRS quality control. The country-wide mean accuracy of the HRS (geoid), version 1 shows an only "<_5_dm_DFHRS_DB Namibia". Die improvement of the DFHRS database for Namibia version 1 can be done - according to the availability of further identical points (B,L,h|H) and new earth gravity models following the EGM 2006 – at any time.

Fig. 1 Accuracy surface of HRS stored in the DFHRS database of Namibia