| 2004 
DIGITAL PHOTOGRAMMETRY IN THE PRACTICE OF OPEN PIT MINING 
A. Patikova 
SST, Prof. Dr.-Ing. Stoll &Partner, Ingenieurgesellschaft mbH, Charlottenburger Allee 39, 520 68 Aachen, Germany 
A Patikova@sst-consult.de, patikova.a(@seznam.cz 
Commission IV, WG IV/7 
KEY WORDS: Photogrammetry, Digitisation, Interpretation, Monitoring, DEM/DTM, Image, Resolution, Stereoscopic 
ABSTRACT: 
Mining activity monitoring, volume calculations, data for information systems of mining companies, decision making and planning, 
reclamation proposals are some of the most important fields, where photogrammetry can be used in open pit mining. Nowadays 
mostly digital methods find their utility in providing stereoscopic digitisation of a current situation of mining, precise orthophotos 
and digital terrain models. There are requirements for high precision especially in heights due to volume calculations and therefore 
high-resolution aerial images with low flight altitude are taken for the open pit mining purposes. The image scale is usually between 
1:4,000 and 1:10,000. The huge amount of photos scanned with high geometric resolution and therefore gigabytes of data have to be 
processed fast and accurately. Fast computers and necessary photogrammetric software together with other ancillary programs (e.g. 
programs for digital terrain modelling (DTM), for computer aided design (CAD), and converters) are a basis of the work. However, 
above all this technical background the human factor is important. Well educated in photogrammetry, specialised in the field of open 
pit mining, experienced people with sufficient software knowledge are needed to achieve good results. 
Despite images with high resolution, the biggest problems are caused by the image interpretation. The terrain of open pit mines 
usually does not show a variety of colours or shades of grey. Therefore shadows can be advantageous but also disadvantageous. A 
very good 3D visual perception without systematic errors is essential in stereoscopic digitisation. The setting of the smallest height 
difference at break lines and slopes is important for their digitisation in order not to lose time with too detailed designs, or on the 
other hand, to avoid a too benevolent work without the necessary details. If a final user of the data has not any photogrammetric 
equipment and uses a variety of software, different result formats are required in both vector and raster data. Specific demands have 
to be discussed very carefully and clearly defined. The paper illustrates also typical actual problems which can be met during the 
workflow. 
1. INTRODUCTION or quarry. It depends on requirements from the side of the open 
pit mining company and their data archive, especially maps, 
Mining companies monitor their mining activity regularly. databases, 3D vector data, digital terrain models, co-ordinates 
There are several possibilities to do so. However, very precise of geodetic points. Very important are metadata, what can be 
terrestrial measurement is a too time consuming technology. simply explained as data about data. They include used co- 
Absolute precision of single points is high (in units of cm) butit ordinate and height systems, the date of the data acquisition, 
IS not economic to measure too many details. With scales, in the case of aerial images also calibration protocols of 
photogrammetry large areas can be measured even with details. the cameras, scanning resolution, information about formats, 
Accuracy at a single point is a bit lower (tens of cm) but still versions of software and so on. Nowadays, bigger mining 
sufficient in the case of open pit mining. Relative accuracy of companies usually have digital vector data describing the status 
DTM is even better than at terrestrial measurement because of a of the quarry. 
higher number of points which can express terrain well. If a previous vector data set exists, the position of the locality is 
Usually, two persons are needed for the terrestrial more or less defined. Then only some differences have to be 
measurement. Photogrammetric processing itself can be done discussed, e.g. an expansion of the mine or quarry in some 
by one person. Only ground control points (GCP) have to be direction in the next years, and then a larger area has to be 
signalised and measured in terrain by the geodetic methods. covered by aerial photos and afterwards processed in a vector 
However, it means just a few points in a comparison to an and also raster (orthophoto) form. If there is no previous data 
evaluation of all points or lines in a quarry or a mine. Therefore, set on hand, the position and the size of the locality has to be 
photogrammetric methods are used more and more often in this defined exactly on the existing map with a suitable scale 
case. Nowadays, mostly digital photogrammetry is applied due (1:10,000 and bigger scale). . 
io many advantages compared to the analytical one. In the case of vector data, the lines, points and areas have 
Nevertheless, there are many specific aspects in the use of special style, thickness and colour. All these attributes are 
digital photogrammetry in the field of open pit mining which defined in a legend or a catalogue of objects provided by 
have to be taken into account for getting proper results. the open pit mining company. 
According to the position of the locality and additional 
2. PHASE OF PREPARATION requirements of the open pit mining company, the flight 
2 dfroject Preparation planning has to be donc. The co-ordinates of the area corners 
and position of the projection centres drawn on the map or 
directly in the last vector data are prepared for the specific 
The first step before any start of a job is the preparati 
p Ys Job isthe preparation of the camera with specific focus length and specific photo scale. The 
existing data and the collection of information about the mine 
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