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Posts from the ‘Technical’ Category


Using metropolitan scale Digital Surface Models for wireless network coverage analysis

The slow propagation of the NBN and the constant demand for high bandwidth services such as Netflix, Stan etc. has created a niche for high bandwidth point to point links and wireless DSL providers. Here are some of their taglines:

“The future’s not faster cables, it’s NO cables” – NuSkope

“Wireless broadband delivers gigabit speeds to residents and businesses now” – Uniti Wireless

“Satisfy your need for speed without the NBN!” – Lightning Broadband


Planning for the point to point links requires detailed knowledge of the line-of-sight since propagation at these frequencies (2.4GHz, 5.8GHz and 24GHz) can be very sensitive to clutter and multi-path interference. Aerometrex provides detailed (50cm cell spacing) Digital Surface Models for Adelaide and Melbourne Metropolitan Area to all the players in the Wireless Broadband segment. We helped Uniti Wireless build a web tool for their customers to analyse the feasibility of receiving a connection as well as an internal tool for planning deployment of new towers.


Adelaide, Melbourne and Mt. Barker datasets (7280 sq. km., 122GB binary data) were ingested into a PostgreSQL/PostGIS database, indexed and stored procedures built to extract full-resolution transects 10km long in less than 1second. Performing line-of-sight operations requires reprojection to ENU (East-North-Up) projection relative to the location of the tower. Algorithms were built reproject from MGA Zones to ENU per analysis and calculate LoS and Fresnel zones. The availability of the accurate DSM and associated rapid/scalable analysis tools has enabled the wireless service providers to expand rapidly and cover most customers with the most efficient placement of towers.Qgis_viewshed

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Geospatial and  photogrammetry: When the mapping world and the gaming world collide

The gaming and the mapping world might look like two very distinct industries but when we give a closer look, we can discern some similarities. Both industries are now more than ever benefiting from each other’s unique features. In one hand, interactive 3D GIS are now using improved graphics, atmospheric and particles effects to visualise real-world data as well as interactive navigation capabilities similar to a video game. In the other hand, maps are the core component of many video games and can be based on either fantasy or real-world information derived from geospatial data. A growing number of games developers have also started to use 3D assets generated using 3D photogrammetry techniques. Read more

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Photogrammetric Modelling of Cars for pedestrian impact simulation

  The CASR Lab does extensive head-bonnet collision testing to assess new car models entering the market for safety.  The limit of deformation of the car’s hood is determined by the gap between the hood and the engine block. Measuring this gap requires extensive 3D modelling of both the hood and the engine block and experimentally testing the deformation at all the sample points requires upto 20 bonnets. In order to augment the direct measurements and destructive testing regiment the lab is interested in acquiring accurate 3D models of the vehicles. Read more »


Systems for acquiring Oblique Aerial Imagery

Oblique imagery got thrust into the spotlight with Microsoft’s publication of the Bird’s Eye imagery to the public. Geo-referenced oblique images are useful for highly automatic creation of 3D city models on their own or in combination with airborne Lidar and planar topographic maps containing building outlines. With the advent of multi-ray matching algorithms using rotation invariant features such as SIFT and SURF, cameras capable of simultaneously capturing multiple view geometries have become highly desirable, making Lidar systems an added complication instead of a complimentary tool. The utility of oblique imagery is now even higher allowing the creation of fully textured 3D models of entire cities given and efficient capture system. Read more »

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How on earth did MH370 end up in the southern Indian Ocean?

Among the myriad of questions surrounding the disappearance of Malaysian Airlines flight MH-370 the biggest question is:

How on earth did MH370 end up in the southern Indian Ocean?

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The Truth about True Orthos

In this article we discuss an innovative way to produce true-ortho imagery where all distortions are corrected and the visible ground surface is maximized. Read more »

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Photography 101

Check out this simple and concise visual breakdown of the basic in photography. Read more »


Aerial Photogrammetry from UAVs

The general trend in all industries is automation, the aerial photogrammetry industry is no different. The advent of digital cameras and poweful computing platforms has automated the image processing workflows from the film camera days. The advent of electric powered aircraft and affordable, small autopilots has made the business of flying and capturing imagery automated as well. The industry has started drawing on all the UAV experience garnered in the defence research and hobbyist arena into commercial products. Read more »

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Dense Matching – 3D Point clouds from aerial and street-level imagery

The UltraMap 3.0 Beta season is almost on us and it promises a great new development in mainstream air-borne photogrammetry. Pervasive availability of 3D point clouds with attached colour information, without requiring a separate Read more »

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Survey of Radar imaging technologies – Satellite Constellations

Visible light only forms a small slice of the electromagnetic spectrum centred at yellow – we have evolved to see things the way we do due to the solar peak radiation being somewhere near yellow. Read more »

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