African Geomatics

Our Projects

Over the past 25 years, we have worked on many interesting and challenging projects.
Below is a selection of our projects.

Geodetic Control

ITRF for Namibia

Zero and First Order Stations in Namibia

In 2005 the Surveyor-General’s Office established Namibia’s zero-order ITRF network based on the ITRF2000, epoch 2005.0, consisting of 22 zero-order stations.

Since then, we have been actively involved in densifying this network to a first-order network. In 2008, we were awarded the tender for the design of a network of first-order stations, which we successfully completed in the same year. The report, entitled ‘First Order Geodetic Network Design for Namibia’, was handed over to the Surveyor-General’s Office in June 2008.

Namibia was divided into a total of 15 project zones.
Since 2008, all first-order stations in project zones 1 to 10 have been constructed, leaving only project zones 11 to 15 to be completed. We constructed the first-order stations in project zones 4 and 5 in 2010, 7 and 8 in 2012, and 9 and 10 in 2020. The first-order stations in project zones 1, 2, 3 and 6 were constructed by another surveying company between 2010 and 2013. The construction of the remaining first-order pillars has been slow due to a lack of funding.

In addition to the construction, we also successfully carried out the observation campaign, processing and reporting for project zones 1 to 5 using the scientific Bernese GNSS processing software in 2015 and 2016. Coordinates in ITRF2000 epoch 2005.0 as well as in ITRF2008 were calculated.

Unfortunately, as with the construction, a lack of funding has made progress on the observation and processing phases of this project very slow.

First Order Pillar

Namibia was divided into a total of 15 project zones.
Since 2008, all first-order stations in project zones 1 to 10 have been constructed, leaving only project zones 11 to 15 to be completed. We constructed the first-order stations in project zones 4 and 5 in 2010, 7 and 8 in 2012, and 9 and 10 in 2020. The first-order stations in project zones 1, 2, 3 and 6 were constructed by another surveying company between 2010 and 2013. The construction of the remaining first-order pillars has been slow due to a lack of funding.

In addition to the construction, we also successfully carried out the observation campaign, processing and reporting for project zones 1 to 5 using the scientific Bernese GNSS processing software in 2015 and 2016. Coordinates in ITRF2000 epoch 2005.0 as well as in ITRF2008 were calculated.

Unfortunately, as with the construction, a lack of funding has made progress on the observation and processing phases of this project very slow.

First Order Pillar

Unfortunately, as with the construction, a lack of funding has made progress on the observation and processing phases of this project very slow.

Cadastral, Engineering and UAV Surveys

Neckartal Dam Project

Neckartal Dam Wall

The Neckartal Dam is located in the Fish River in the Karas region. It is the largest dam in Namibia and has almost three times the capacity of the second-largest dam, the Hardap Dam further upstream. Construction of the Neckartal Dam started in 2013 and was completed in 2018.

Our involvement with the Neckartal Dam project dates back to 2009, when we carried out the groundwork for a LiDAR survey of the dam basin and the land suitable for agricultural purposes in the vicinity. This first control network then formed the basis for all further surveys carried out for the Neckartal Dam project.

Pillar at Neckartal Dam

Our involvement with the Neckartal Dam project dates back to 2009, when we carried out the groundwork for a LiDAR survey of the dam basin and the land suitable for agricultural purposes in the vicinity. This first control network then formed the basis for all further surveys carried out for the Neckartal Dam project.

Neckartal Dam Area before Construction

One major challenge of the dam site was its remoteness: it was approximately 30 km from the nearest tar road in very rugged terrain. When it was apparent that the dam would be constructed, we were appointed again to survey the control network for the access road in 2011. After the access road was completed, we remained engaged with various tasks throughout the project until 2019.

The additional tasks included the following:

  1. Survey of the forced centering pillars at the dam site, the abstraction works and along an 8.5 km long pipeline from the abstraction works to the holding dam, based on our previous survey of 2009. These forced centering pillars were the basis for all setting-out surveys throughout the project duration.
  2. Monthly aerial UAV surveys of the dam site, the abstraction works and the quarry site from 2014 to 2016. For the dam site and the abstraction works we overlaid the design of the works with the orthophotos and the DTMs. This information was vital to our client in detecting any irregularities. Using photogrammetric survey methods for this task with UAV technology was very innovative at the time and this technology proved to be much faster than any conventional survey method for a project of this nature.
  1. In 2014 we carried out a major cadastral survey of the dam site, the abstraction works and approximately 5,500 ha of farmland that is to be utilised for the agricultural irrigation scheme of the Neckartal project.
  2. Our final involvement with the Neckartal Dam was a servitude survey over the 8.5 km long pipeline between the abstraction works and the holding dam for the irrigation scheme.
Drone in Front of Neckartal Building Site
  1. In 2014 we carried out a major cadastral survey of the dam site, the abstraction works and approximately 5,500 ha of farmland that is to be utilised for the agricultural irrigation scheme of the Neckartal project.
  2. Our final involvement with the Neckartal Dam was a servitude survey over the 8.5 km long pipeline between the abstraction works and the holding dam for the irrigation scheme.
Aerial Image of Neckartal Dam Construction with Planning Overlay

Geodetic Control

Control Points in Kavango Region

Trigonometrical survey control is very sparse in northern Namibia. In 2003 and 2004 the Namibian Government decided to survey some 275 new farms in the Kavango West Region. Each farm is of the order of 2,500 ha and the total area to be developed was approximately 6,500 km², i.e. an area of some 65 km x 100 km. The area is located just west of the Khaudum National Park and is very inaccessible by any mode of transport due to thick sand and only a few old tracks.

We were appointed by the Surveyor-General’s Office to densify the existing trigonometrical network in the area to one control point every ±20 km. The purpose of this densification was to provide sufficient survey control in the area to survey the 275 farms to a high degree of accuracy.

Overview Map of Kavango Farms and Control Points

We were appointed by the Surveyor-General’s Office to densify the existing trigonometrical network in the area to one control point every ±20 km. The purpose of this densification was to provide sufficient survey control in the area to survey the 275 farms to a high degree of accuracy.

We constructed a total of 29 control points, most with witness marks. These were then connected to the few trigonometrical beacons in the area with static GNSS survey methods. The total network area covered some 180 km by 125 km, all in thick sand, with a maximum speed of approximately 40 km/h.

We constructed a total of 29 control points, most with witness marks. These were then connected to the few trigonometrical beacons in the area with static GNSS survey methods. The total network area covered some 180 km by 125 km, all in thick sand, with a maximum speed of some 40 km/h.

This project was very challenging in terms of logistics. We had to get enough material to each point for its construction, ensure that the GNSS receivers were running long enough to provide sufficient common observation times between stations, and do all this without any communication between the survey teams. Years later, in 2018, we reused some of the 29 control points to survey new first-order ITRF pillars on the Schwarzeck datum in the area, and were pleased to find most of the control points in good condition.

UAV and Cadastral Surveying

Osona Township

Osona Village is a 1,100 ha mixed-use development currently being developed in the municipal area of Okahandja (development video). Osona Village will eventually comprise residential, commercial, retail, agricultural, industrial and educational facilities, with approximately 10,000 dwellings. Currently, the main focus is on providing affordable, high-quality housing.

Our firm has been actively involved throughout the project. We have produced the orthophoto of the 1,100 ha development area and contours at 0.5 m intervals, which were used for all urban design and town planning purposes. In addition, we have carried out aerial UAV surveys of the Osona reservoir site, as well as several surveys to monitor the development of Osona Village.

On the cadastral side, we surveyed the initial portions acquired for the Osona Village development in 2013. Since 2013 we have surveyed a total of 14 extensions of Osona Village, comprising approximately 4,300 erven.

Osona Aerial Image with all Planned Extensions and Zoning

Our firm has been actively involved throughout the project. We have produced the orthophoto of the 1,100 ha development area and contours at 0.5 m intervals, which were used for all urban design and town planning purposes. In addition, we have carried out aerial UAV surveys of the Osona reservoir site, as well as several surveys to monitor the development of Osona Village.

On the cadastral side, we surveyed the initial portions in 2013 that were acquired for the purposes of the Osona Village development. Since 2013 we have surveyed a total of 14 extensions of Osona Village, comprising approximately 4,300 erven.

Engineering Surveying

Road Surveys

Over the years, African Geomatics has been involved in numerous road projects. The surveys were mostly for detailed design purposes, and different survey strategies were applied for different circumstances. On all roads, first-class survey control was established using GNSS survey techniques and digital spirit levelling. DTMs were then created either with GNSS survey methods, UAV surveys or outsourced LiDAR surveys.

African Geomatics has been involved in the following major road projects:

  • Aus – Rosh Pinah
  • Rosh Pinah – Oranjemund
  • Okahandja – Karibib
  • Ondjiva – Cuvelai (Angola)
  • Nkurenkuru – Elundu
  • Swakopmund – Walvis Bay
  • Khorixas – Uis
  • Windhoek – Okahandja
  • Windhoek – Hosea Kutako International Airport

Geodetic Control

Local Transformation Parameters - Northern Namibia

In Namibia published datum transformation parameters from the Schwarzeck datum to the ITRF (WGS84-based system) are only accurate to approximately 30 m countrywide. In Northern Namibia the published parameters are known to be accurate to approximately 8–15 m.

During our observation and processing campaign in 2015 and 2016 for project zones 1 to 5 (see ITRF for Namibia) in Northern Namibia, we also included Trigonometrical Beacons in the Schwarzeck system to determine transformation parameters for each Zone.

Map of Zones 1 to 5 in Northern Namibia

During our observation and processing campaign in 2015 and 2016 for project zones 1 to 5 (see ITRF for Namibia) in Northern Namibia, we also included Trigonometrical Beacons in the Schwarzeck system to determine transformation parameters for each Zone.

Local transformation parameters between the Schwarzeck datum and ITRF2000 datum were calculated for each of the five zones.
Compared to the world, each zone is relatively small, and unless the points used to compute the transformation parameters are widely separated, it is difficult to isolate the effect of a rotation from a pair of translations. The most common approach is to assume that the rotations and the scale factor are negligibly small and to determine the translations only. This is achieved by differencing the Cartesian coordinates of common points and taking the weighted mean. This was the approach that we used for the computation of new parameters for the five zones.

The results for the five zones are listed in the table, together with the error estimates.

Table with Transformation Parameters

Zone 1 in the Kunene Region in the northwest of Namibia is one of the most remote and inaccessible parts of the country. The terrain is mostly mountainous, there are few roads, and the beacons along the coastline lie in the restricted Skeleton Coast conservation area.

Zone 1 in the Kunene Region in the northwest of Namibia is one of the most remote and inaccessible parts of the country. The terrain is mostly mountainous, there are few roads, and the beacons along the coastline lie in the restricted Skeleton Coast conservation area.

A helicopter was used to reach the Coastline Beacons from Torra Bay up to the Kunene River mouth. The helicopter was also used to reach the Trigonometrical beacons on the high mountains. The helicopter pilot required considerable skill, as coastal fog often extended many kilometres inland. Sometimes only the mountain tops were visible above the clouds. (Photos courtesy of the helicopter pilot)