MAIN ACTIVITIES OF

GENERAL COMMAND OF MAPPING (GCM) TURKEY

MARCH 2012

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CONTENTS MAIN ACTIVITIES 1. Geodetic Activities, 1 2. Photogrammetric Activities, 4 3. Cartographic Activities, 11

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1. GEODETIC ACTIVITIES

1.1. Turkish National Fundamental GPS Network

Turkish National Fundamental GPS Network (TNFGN) consisting of about 700 stations has established through surveys between 1997 and 1999. Following the establishment of TNFGN, the periodic GNNS measurements have been carried out providing sub-centimeter and millimeter precision for the coordinates and velocities, respectively. The distribution of TNFGN stations is given in Figure 1.1.

Figure 1.1. Distribution of TNFGN stations.

1.2. Turkish National Permanent GPS Network and Turkish National Permanent Network-Active

The Turkish National Permanent GPS Network (TNPGN) dates back to early 1990s. A new Real-Time Kinematic Network consisting of 146 stations has also been in use since 2010 which provide sub-decimeter level real-time positioning accuracy. The distribution of TNPGN and TNPGN-Active are shown in Figure 1.2.

: TNPGN Sites (27) : TNPGN-ACTIVE stations(146)

Figure 1.2. Distribution of TNPGN and TNPGN-Active stations.

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1.3. Ionospheric Studies A project was initiated between General Command of Mapping (GCM) and Hacettepe University (HU) to determine in real-time the 3D ionospheric tomography of Turkey was supported by Turkish Scientific and Technological Research Council (TUBITAK). The project involves the independent software implementation of ionospheric processing algorithms and real-time determination of ionospheric disturbances for possible precursors such as earthquakes.

Figure 1.3. The variation of Vertical Electron Content on 27.10.2008.

1.4. GPS Meteorology

More than half of the GPS stations were installed in meteorological parks of General Directorate of State Meteorology. Such a coupling not benefit from high precision meteorological measurements at GNSS stations but also provides GNSS-derived PW values which are invaluable in short-term precipitation forecasting.

Figure 1.4. The variation of PW values near Ankara and the neighboring stations

on 16 June 2011.

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1.5 Turkish Sea Level Monitoring System

Sea level measurements are carried out under the sea level monitoring network consists of 20 tide gauge stations located on the surrounding coasts (Figure 1.5). High frequency sea level data collected at these stations are used for the determination of tidal characteristics, tidal prediction and tidal datum planes, seasonal to long-term sea level variations, and other ocean-atmosphere studies. In addition it serves as complementary dataset to seismic and geophysical measurements for the tsunami early warning systems.

Figure 1.5. Locations of the existing tide gauge stations of TUDES

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2. PHOTOGRAMMETRIC ACTIVITIES 2.1 Introduction

Photogrammetrical applications have been carried out successfully since 1940’s. Depending on the amendments in mapping regulations and classifications, private sector have also taken place in various applications for at least twenty years.

Photogrammetric works comprise of photogrammetric data capturing, topographic completion,

image enhancement, orthophoto production, image archiving and database management processes. 2.2. Photogrammetric 3D Data Capturing The demand for accurate and up-to-date spatial information is increasing and its availability is becoming more important for a variety of tasks . For the time being, topographic map production is the main consumer of topo-data. Topographic data contains multiple super-feature classes which consist of features such as terrain, forest, vegetation, roads, lakes, buildings, and geographic names. Vector data for 25K scale topographic map productions have been collected by means of photogrammetric methods. GCM has 2 Beechcraft B-200 aircrafts for these photogrammetric purposes. At the ends of 2007, the Microsoft UltracamX Digital Aerial Camera with an IGI GPS/IMU system was purchased. It has been used successfully in the map production work flow of GCM since 2008. In 2012 another large format digital camera system will be purchased. By the end of 2011 nearly 65% of Turkey has been covered with digital aerial photographs. Three-dimensional topological vector data for 25K scale topographic maps are collected from stereo models using digital photogrammetric systems. These data are compiled in the field with complete GPS/GIS data collection sets and attributes collected in the field are appended to the vector data. All vector and tabular data are modified and edited for the 25K Topographic Database. The 3D vector data collection for almost 80% of Turkey will be finished by the end of 2012. 30 % of this vector data has been gained by out-sourcing. Apart from the regular stereo plotting and revision of the 25K maps, some customized solutions have been developed in order to meet the user requirements. Among them, Digital Orthophoto Presentation System which contains orthophoto maps of the cities at various scales is the foremost one. Additionally, GCM carries out some research and development studies at national/international level on utilization of airborne SAR and satellite images. 2.3. Image Enhancement and Ortho-Imagery/Photo Works and Archieving

Ortho-rectified imagegery/photo is produced as succeeding work after aerial photography for

revision. GCM DEM, NASA-SRTM 1/2 and ASTER DEM2 are being used for ortho-rectification. Several image processing software such as ERDAS, Leica Photogrammetry Suite (LPS) and PCI are used for image enhancement and ortho-imagery works. Following activities are the main ones in this context;

− Performing aerial triangulation (adjustment) of aerial-photos,

− Orthorectification of aerial photos and remotely sensed imagery,

− Mosaicing and clipping due to required frames or grids,

− Enhancing ortho-imagery/photo for photo interpretation and information extraction,

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− Pan-sharpening.

Digital Archive Information System is aimed to scan all aerial photographs by the photogrammetric scanners in GCM archive and query these data on the web. System has started to service in 2007 and scanning of photographs is still going on. 2.4. Digital Orthophoto Presentation System The Project has just started after the 1999 Gölcük Earthquake with a view to provide quick and detailed geographic support that may be vital for decision makers. A software has been developed for the usage of the geodatabase comprised of several layers (Figure 2.1). It allows the user to view images at any desired scale through zoom-in/out, to make 2D digitization, to compare the pairs of the photos taken at different times, to conduct some basic measurements such as distance to/from a given point and area, to print out images in part or wholly at any form and scale, visualize the topography 3D, etc. Orthophoto production for 149 populated places has been completed.

Figure 2.1. Screenshot of developed software 2.5. Multinational Geospatial Co-Production Program and Image Interpretation Works for Topo Data Capturing General Command of Mapping (GCM) has participated in the Multinational Geospatial Co-Production Program (MGCP) by signing the Memorandum of Understanding (MOU). Under MGCP, Participants may co-produce and share High-Resolution Vector Data (HRVD) over current high interest areas. After the training of personnel, GCM began the production in 2007 by using the up-to-date satellite imagery as a main data source. Production is going on according to the standards defined by the MGCP team.

Topo data capturing for MGCP consists of a sequence of processes such as image interpretation, feature extraction, editing, attribution, populating in a database and QC procedures. The software used for these tasks are ESRI ArcGIS, ESRI Defense Solutions such as PLTS and GAIT. Following activities are done within data capturing works.

− 2D Feature Extraction,

− Attribution,

− Contour Editing,

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− Topo-database population,

− Quality Control Procedures,

− Metadata.

2.6. Topographic Data Completion After completing the photogrammetric feature extraction process, the collected data are

completed and validated in the field. Following works are carried out in the field to complete the photogrammetric vector data.

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Figure 2.2. Collecting the features that are not extracted in photogrammetric feature extraction.

Figure 2.3. Correcting the erroneous features.

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Figure 2.4. Collecting the feature attributes and validating and collecting the names of the features and populated places.

For collecting the data in the field, the Digital Data Collection System is used. The system consists of four components shown below.

(a) GPS Receiver (b) Laser Rangefinder and Electronic Compass

(c) Tablet PC (d) Data Collection Software

Figure 2.5. Digital Data Collection System components.

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2.7 Topographic Vector Database (TOPO25)

GCM has established a 25K scaled Topographic Vector Database (TOPO25) for storing the vector data.

The reasons for a Topographic Database Requirement:

• To provide geographic data in a continuous structure,

• To provide instant access opportunity to data,

• To increase the efficiency of map production process,

• To form the data with appropriate data models to represent the real world,

• The opportunity for making geographical queries,

• The opportunity of portraying the data on the web.

The main properties of the Geodatabase are: • The real world features are represented by 128 feature classes and 352 feature sub-types

in the database. Several attributes are defined for each feature class. Attribute Domains are defined for the required attributes.

Figure 2.6. Features in Database

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Figure 2.7. Sub-types in Database

• There are 208 topological rules in the database. All data in the database must be consistent with these rules.

Figure 2.8. A topological rule sample.

• The database stores the data in a continuous structure for the whole country. It is independent from any map sheet or border.

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Figure 2.9. Continuous data independent from map sheets.

• The data are stored in 3D structure.

• To provide the data continuity in whole country, Geographical Coordinate System and

WGS84 Datum are selected.

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3. CARTOGRAPHIC ACTIVITIES 3.1 Digital Topographic Map Production: Digital topographic map productions have been continued in 2011.

For the 1:25 000 scale digital map production, 4261 maps out of 5547 sheets have been produced till 2011.

Using these map data and KartoGen cartographic generalization software, developed by General Command of Mapping, 769 maps out of 1453 sheets at 1:50 000 scale and 203 maps out of 391 sheets at 1:100 000 scale have been produced till 2011. Various generalization results of KartoGen software are shown as vector map layers at Figure 3.1.

(a) Elevation feature class

(b) Transportation feature class

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(c) Hydrography feature classes

(d) All feature classes

Figure 3.1: Samples of different feature classes, before and after generalization processes.

For the 1:250 000 scale charts, TFC series chart productions have been continued besides JOG series chart productions. JOG and TFC series charts have been produced till 2011 for the 67 charts out of 71 sheets that cover Turkey. Charts belong to JOG Air and TFC series are depicted at Figure 2 and 3.

Figure 3.2: Sample of 1:250 000 scale JOG-Air Chart

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Figure 3.3: Sample of 1:250 000 scale LFC Chart For the 1404 series 1:500 000 scale map productions that began in 2007, 12 maps out of 18 sheets that cover Turkey have been produced. 3.2 Thematic Map Production:

In 2011 it was focused especially on production of single part thematic maps having different

themas. In this context World Political and World Physical Maps were prepared. These maps were based on the Country Names and Capitals file, finalized by Turkish Group of Experts on Geographical Names in 2011. 3.3 Productions for Eurogeographics:

In 2011, it has been begun for updating and refinement of 1/1 M Scale Vector Maps. In addition to production of maps for Turkey, by the help of these efforts it can be possible to handle;

a. Production of EBM data

b. Production of EGM data and data supply to these groups in 2012 on behalf of Turkey.

Turkey Gazetteer has been prepared in this context. Development efforts of the gazetteer named Turkey and Neighborhood that has been published since 2010 went on in 2011. Parallel to

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these studies, Turkey Settlement Areas DataBase improvement studies has been started. It is anticipated to finish this work until the end of 2012. 3.4 Research Activities

Started in 2008, research activities concerning holographic maps with 3D effects on 2D

surfaces have been going on. Several prototypes of the Holographic Maps (Figure-4) have been developed and exhibited at

some national and international conferences. Due to the project timeline, some new and advanced techniques are planned to be implemented until the end of 2014.

Figure 3.4: The prototypes of holographic maps