Home Articles A GIS Assisted Knowledge-Based Approach for Military Operations

A GIS Assisted Knowledge-Based Approach for Military Operations

Maj. R. Baijal*, M. K. Arora and S. K. Ghosh**
Geomatics Engineering Section, Department of Civil Engineering
Indian Institute of Technology Roorkee, Roorkee 247 667
*[email protected], **[email protected]

Military history is full of incidents wherein a smaller army having a good knowledge of the terrain has defeated a much larger well-equipped and organised army. Nearly, all military activities are terrain sensitive and need careful planning and reconnaissance to ensure success. However, planning of military operations is a complex process and is guided by the experience and capability of the commander and his staff who provide the necessary inputs to him. This decision making process can be made intelligent by developing Knowledge Based (KB) expert systems. In this paper, a knowledge-based approach has been used to produce a number of thematic maps useful for various military operations. The approach developed is capable of taking inputs in the form of data layers that may be generated from satellite images, aerial photographs, topographical maps or other ancillary data. Some common military operations such as selection of sites for bridges, ferries and helipads, identification of tactically important roads and vehicle mobility movement are considered. The development of such knowledge-based approached shall tremendously assist the military commander to provide efficient and real-time information in an organized way for any military task.

With the present cold war situation between India and its adjoining neighbour, the defence forces have to be on alert at all times. Any emergent situations means that the army has to move towards the border at a very short notice. The modern battlefield is highly mechanized with heavy arms and ammunitions to shift around. The mobility of any armoured column depends upon the terrain conditions over which it has to move. Ground conditions have always played an important role in all conflicts over the ages. The parameters like topography, soil type and land use land cover have a direct bearing to key activities like mobility of both men and machines, methods of crossing obstacles, selection of tactically important areas etc. Logistics also play an equally important role as weapons in a war. Replenishment of ammunition, fuel and other supplies are required to reach the fighting troops in time. These require careful planning in terms of routes to be taken and movement of various types of vehicles to ensure success. Thus, in today’s modern battlefield, speed of planning and execution of operations is of prime importance.

Fortunately, we are living in an Information Technology (IT) era where the dissemination of information from one place to another has virtually become real time. The IT tools can be sufficiently exploited for any challenging task such as planning of wars. Remote sensing, Geographical Information System (GIS) and artificial intelligence technologies are sitting on the top of these IT tools that can together be effectively utilised to develop intelligent systems for war planning. Command, Control, Communication, Coordination and Information (C4I) is one such system where these technologies can be effectively used. For example, satellite remote sensing data can be used to generate a wide range of products such as land use land cover maps, obstacle maps, slope maps, road mobility maps, line of sight plots etc. A GIS can receive, process, create, store, retrieve, update, manipulate and compress digital terrain data to generate a number of products. Knowledge of experts is a key input for any C4I system. Knowledge Based (KB) systems are being developed for war planning that can process inputs from remotely sensed and GIS derived products and use the knowledge gained to aid the decision making process, thereby allowing the military commanders make better battle plans. GIS embedded C4I systems aim to give this KB to field commanders and their staff who despite having little knowledge of GIS, can work on such systems. Currently only a few C4I systems are in use with embedded GIS, but their numbers are likely to rise substantially soon as more and more systems are developed around the world.

This paper presents a study on the use of a GIS assisted knowledge-based approach for some military operations such as selection of sites for bridges and helipads, identification of tactically important roads and preparation of vehicle mobility maps.

Some common military operations
The commanders have to carry out careful planning of a range of activities required during any military operation in war. Some of them are:

Selection of Sites for Launching Bridges
To provide mobility to ground forces across water bodies, two types of bridges are generally employed by the military. Wet bridges are built across the rivers and large water bodies where these can float. For small water bodies such as canals and drain, dry bridges clear of the water surface are provided. However, these bridges have fixed specifications of span, launching slope and bank conditions. Therefore, a suitable site has to be selected to meet these requirements with some site preparations. Selection of Ferry Sites

For crossing the canals and rivers, suitable ferry sites are needed till bridges are constructed over them. The terrain requirement is somewhat similar to bridges except that some form of road or track on the banks of the water bodies to provide access to the ferry site is required.

Selection of Sites for Helipads
During the movement of the troops and equipment, sufficient air cover essential in today’s warfare, as these are easy targets from air by the enemy. Keeping the capabilities of a helicopter in mind, it is being increasingly used in combat role and other tasks like reconnaissance, evacuation of casualties etc. The dimensions of the helipad required for the landing of a helicopter varies from place to place but the ground conditions may nearly be the same as for bridge and ferry sites. For example, the location of a helipad depends upon the tree cover, soil conditions and slope of the ground.

Identification of Tactically Important Roads
In order to provide fast and safe movement of troops and equipment, identification of tactically important roads is essential. Roads and tracks that lead up to the likely bridge or ferry site are tactically important and need to be identified and suitably constructed so that these may be used as the axis of maintenance. Ideally these roads should not pass through any obstacles like the minefields.

Preparation of Vehicle Mobility Maps
Military vehicles are generally classified into two broad categories, tracked and wheeled. Vehicles like tanks have excellent cross country mobility due to presence of tracks over its wheels. However vehicles having wheels but without tracks do need careful route planning before cross-country movement can be attempted. Vehicles carrying essential war stores like ammunition; fuel and other supplies are all wheeled vehicles.

The need for a knoowledge based approach
The activities mentioned above are just a few undertaken by the defence forces while planning for a military operation. Most of these require good interpretation skills to understand the terrain. These skills may vary from person to person and hence the interpretation is also likely to vary. This may adversely affect the battle plan therefore, there is a need to standardize procedures and incorporate systems, which use the existing knowledge acquired by experts, intelligence agencies and other means. This knowledge base (KB) can be effectively used to make accurate decision making tools which can easily be used by military commanders at all levels.

KB expert systems can be developed, which can take into account the experience and knowledge of terrain analysts and other experts to convert them into a set of rules, which can then be applied to digital data to derive a number of thematic maps that can in turn be used in war planning.

A typical KB system comprises of a set of interrelated and interconnected components such as knowledge base, inference mechanism (IM), user-interface, mechanism to update KB, and the explanation of the rules applied (Nikolopoulos, 1997). The KB is a systematic collection of information from various sources and experts in the area of application (e.g., war planning here). It is organizes the information into rules, which are generally written in the form of IF-THEN-ELSE statements. The IM is the work center as it provides the deductions or solution to a particular problem based upon the rules framed. The user interface is the link between the user and the KB such that a non-expert can also use it comfortably. With passage of time, the KB has to be updated in terms of informations and rules, thus Mechanism to update KB is an essential facility to upgrade and check the validity of KB. Generally, a KB system shell is built that houses the IM, the user interface, an explanation system and a knowledge base editor. There are numerous commercial KB system shells, each one appropriate for a slightly different range of problems. Using shells to prepare a KB system generally reduces the cost and time of development.

In this paper, the knowledge based classifier in the well known Image Processing and raster GIS software namely ERDAS Imagine has been used as a shell to develop a knowledge-based approach for the military operations mentioned above.

Study area
The KB presented here has been designed keeping in mind its effective use in the western borders of our country. In the western region, the general terrain conditions are plain with the soil type varying from desert sands of Rajasthan to the marshy areas of Gujarat. The landscape in this region is interspersed with rivers and canals.

However, due to the security restrictions in use of topographical sheets of the border areas, an area having somewhat similar ground conditions has been selected here to test the knowledge-based approach developed. The area lies south of Saharanpur city, UP, between Latitude 29°45′ to 29°50′ and Longitude 77°30′ to 77°35′. Survey of India (SOI) map sheet 53 G/9 having a scale of 1:50,000 has been used. The area covered is approximately 8 Km by 8 Km. This area has one major river Hindan flowing from north to south and few canal systems as shown in Fig 1.

Fig. 1 Topographical map of study area selected
GIS Data Layers
The rules to be formed are based upon the spatial information about the terrain as desired by a particular military operation. A number of spatial raster data layers are prepared. The data for the study area has primarily been collected from the topographical map as above. However, due to non-availability of certain information, some hypothetical data has also used for the preparation of layers. Following data layers have been prepared by on-screen digitizing the scanned topographic map in ERDAS Imagine,

  1. Water Bodies
    In the study area one major river, River Hindan, is flowing from north to south with a network of canals, to the north west of the area and some small lakes around villages. Thus, three categories of water bodies are considered as rivers, canals and lakes with their raster values assigned as 1, 2 and 3 respectively (Fig. 2).

    Fig. 2 Thematic layer of water bodies

  2. Road network
    Existing roads and tracks are an important aspect as it ensures the smooth movement of both fighting columns and logistical supplies. The area has a good network of roads and tracks both along the river and perpendicular to it. The roads and tracks are therefore the automatic choice for the categories in roads layer and are assigned a raster value of 1 and 2 respectively (Fig. 3).

    Fig. 3 Thematic layer of road network

  3. Power Lines
    Existence of power lines is an important factor while deciding the location of helipads. Hence, power lines have also been digitised and assigned a raster value as 1 and rest of the area as 0 where no power lines exist (Fig. 4).

    Fig. 4 Thematic layer of power lines

  4. Slope Map
    The area is in general flat with heights varying from 252 m to 267 m. Only one contour at 20 m interval passes in the vicinity of the area. Therefore, spot heights and benchmarks available on the topographical sheet have also been digitized to generate a Digital Elevation Model DEM. 3D surfacing tool of ERDAS Imagine has been used to generate a raster DEM from the digitized contour and the spot heights (Fig. 5). From this DEM, a slope map has been prepared showing four categories as, no slope (0% slope), plain (slopes less than 5 percent), moderate (slopes between 5 to 10 percent) and steep (slopes greater than 10 percent) (Fig. 6).

    Fig. 5 Raster DEM of study area

    Fig. 6 Thematic layer of slopes
  5. Land use land cover map
    IRS-LISS III data has been used for classification of various land use and land cover of the area. Five land use land cover categories namely built-up areas, forests, rivers, canals and cultivated areas have been selected and given raster values as 1, 2, 3, 4, and 5 respectively (Fig. 7).

    Fig. 7 Thematic layer of land use

In addition to the above data layers, two more data layers have been prepared based upon the hypothetical data,

  1. Soil map
    Soil conditions play an important part in the process of site selection for various military tasks like bridging, helipad location etc. The factors like bearing capacity and the soil moisture are critical for operations like bridging. Approach to site and area near a bridge must be able to take on heavy vehicular traffic. Due to lack of authentic soil map of the area, a hypothetical soil data has been generated and is classified into three categories namely sand, silt and clay with their raster values as 1, 2 and 3 respectively (Fig. 8).

    Fig. 8 Thematic layer of soil types

  2. Water depth
    Wet Bridges are built using pontoons having decked girders, which float on water. Hence there is need for minimum water depth, which is generally kept as 1m. In absence of authentic data, hypothetical water depth data for the river in the study area has been generated and divided into two broad categories as adequate or inadequate with raster values assigned as 1 and 2 respectively (Fig. 9).

    Fig. 9 Thematic layer of water depth


Generation of rules for the KB
Knowledge acquired in the form of GIS data layers converted into rules that are transformed into a knowledge base using the Knowledge Engineer (KE) shell of ERDAS Imagine. Each data layer provides a parameter or condition, which can be used for the formation of rules to get the final hypothesis. Separate knowledge base has been prepared for each military operation selected in this paper. For brevity, the KB for the selection of wet bridging site has been described here. However, all the graphical representations of each KB are shown in Fig. 10 to Fig. 15.

Fig. 10 KB for Selection of Wet Bridging Sites

Fig. 11 Knowledge Base for Selection of Dry Bridging Sites

Fig. 12 Knowledge Base for Selection of Ferry Sites

Fig. 13 Knowledge Base for Selection of Helipad Sites

Fig. 14 Knowledge Base for Identification of Tactically Important Roads

Fig. 15 Knowledge Base for Preparation of Vehicle Mobility Maps

For launching a wet bridge, the parameters that are likely to be considered are type of water body, ground slope, type of soil, land use and availability of adequate water depth. The KB for the selection of wet bridge site consists of the following rule written in the text form as: IF WATER BODY == RIVER (1)
THEN SUITABLE SITE FOR WET BRIDGING The numbers in the bracket show the respective raster values. On executing this KB, the hypothesis gives the output class (colour coded as red) as the possible site locations for the wet bridge (Fig. 16).

Similarly, once the KB for each military operation is executed, outputs are a set of thematic maps, which are shown in Fig. 17 to Fig. 20. These thematic maps have been visually analysed with the input images in relation to the rules applied. The broad areas as identified by each KB have been checked using topographical map and military data regarding parameters for the various military uses, and have been found to be correct. Thus, the KB approach can be effectively used for military operations. The thematic maps thus produced can be also used as overlays to carry out an accurate planning for various military tasks.

Accurate and timely terrain analysis is the key for today’s fast paced mobile battlefield. Conventional techniques need to be updated due to availability of data products like maps in digital form and high-resolution satellite imagery. The knowledge base approach for the interpretation of terrain features will prove to be very useful for modern day war planning. This approach combines the experience and knowledge of experts and delivers this to the soldier in the battlefield.


  • ERDAS (1999), ERDAS Imagine Expert Classifier, ERDAS Inc, USA. Sensing Journal, Vol 5, pp 67-69.
  • Nikolopoulos C. (1997), Expert Systems: Introduction to First and Second Generation and Hybrid Knowledge Based Systems, Marcel Dekker Inc, USA.