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Posts from the ‘Photogrammetry applications’ Category

23
Nov

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

antennas_small

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.

uniti_clients_blur

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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22
Nov

Quantitative Coastal Erosion Monitoring using Photogrammetry

Aerial and Ground based Lidar and photogrammetry have been used individually and in combination to monitor coastal erosion. We have developed our oblique photogrammetry with multi-ray matching technique to a point where these methods can be replaced by a single dataset captured using Aero3dpro methodologies. With accurate survey control multiple epochs are exactly aligned and suitable for displacement analysis and volume calculations of material lost due to erosion.

A test site was chosen near Darwin, Northern Territory, Australia. The area known as Nightcliff has been featured in the voyage of the Beagle and is the site on the Nightcliff market of Sundays. Thus the area is of historical and social importance. This area has had a lot of cliff loss due to erosion and a coastal management plan has been put in place to construct a sea-wall along the foreshore. Datasets captured in 2014 and 2016 clearly show these changes and provide quantitative displacements, which can be calculated using Hausdorff distance algorithms on the reconstructed meshes. A plot of the displacement can be seen in the image below.

Nightcliff Displacements

Nightcliff Coastal Erosion and displacements

An interactive model of this area can be viewed in the Cesium viewer below, it also includes Darwin background ortho imagery from MetroMap.

Nighcliff

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19
May

20 Things They Don’t Tell You About UAVs

The energy, enthusiasm and the inventiveness that is going into UAV* technology these days is truly remarkable. There has been a proliferation of manufacturers, suppliers, users and conferences promoting the technology. We have all seen stunning video clips and images taken from UAVs – the low altitude aerial perspective enables unique views of a wide sweep of surrounds as well as the foreground focus of attention.

In July 2012 I attended the ESRI International User Conference in San Diego and assisted a UAV manufacturer on their trade exhibit, fielding questions from potential customers of this technology. It was a revelation, not only because of the technology, but because of the reaction of the punters. I could see it in their eyes. Everyone wanted to do this for a job. “Get paid to have fun? I’m in!” Read more

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14
Sep

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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12
Feb

Coastal erosion mapping using 3D photogrammetry

Coastal erosion is the wearing away of land along the shoreline due to the natural removal of beach or dune sediments caused by wave action, wave and tidal  currents, high winds, drainage and other human-induced causes of erosion . Rising sea levels, more frequent storms and cyclones are also increasing coastal erosion and are putting infrastructures, properties and people at risk. Read more »

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5
Jan

Satellite images of the Sampson flat fire Adelaide Hills – January 2015

The Sampson Flat bushfire which started on Friday 2nd January 2015 in the Adelaide Hills  has blackened more than 12,000 hectares so far.

The following article shows a collection of satellite imagery showing the extent of the damage. Read more »

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13
Nov

Virtual 3D city models: A base dataset for Australian States departments and local councils

An increasing number of Australian states government departments and local councils are using or are in the process of acquiring virtual 3D city models as part of their planning and development strategy. In addition to other geospatial information layers integrated into interactive 3D GIS solutions such as Skyline TerraExplorer, these new tools provide intuitive and innovative ways to communicate complex information and develop long-term management strategies. Read more »

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4
Nov

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 »

31
Oct

Integration of 3D streetview earthmine with interactive 3D GIS Skyline Terraexplorer and aero3Dpro city model as a base dataset

Integration test of 3D Street Level Imagery Solutions earthmine into Skyline Terraexplorer pro.

The 3D base dataset is a virtual 3D city model of Karratha, WA generated with aero3dpro.

Users can navigate in the earthmine window and the corresponding location will be displayed into Terraexplorer in real-time.

Users can also pick up a location on the virtual 3D model and the corresponding streetview will load in the earthmine window. Read more »

11
Aug

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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