Shaping The Land Battle Through Remote Sensing And Satellite- Imagery

Brig Satbir Singh, Senior Fellow, IDSA


Technical Intelligence (TECHINT) and Space Reconnaissance are the most prolific, reliable and accurate means of intelligence collection. Techint consists of Signal Intelligence (SIGINT) and Imagery Intelligence (IMINT). Signal Intelligence has two components i.e. Communication Intelligence (COMNINT) and Electronic Intelligence (ELINT). Imagery Intelligence is both aerial and satellite.

Gaining of accurate information, its analysis, evaluation and dissemination within the time-frame it is required, has been the challenge for military planners. The rapid advancement in science and technology has ushered in the Revolution in Military Affairs (RMA). Intelligent and sophisticated sensors, precision navigation data, secure and reliable communications apart from widespread commercial and economic benefits, provide better understanding of the battlefield. With the help of these technologies, intelligence collection, surveillance and reconnaissance has come within the realm of real-time availability both during day and night and in any kind of weather thus making the whole battlefield transparent to us. It will be possible to pick, locate and track units, identify facilities and weapons, the destruction of which would debilitate the opponents ability to fight.

Remote Sensing and Satellite Imagery, in conjunction with other means of gaining intelligence, has qualitatively improved the potential of armed forces wherein commanders in the field will be in a position to have real-time accurate information of the battlefield thus enhancing their decision-making capability.

Remote Sensing implies, sensing from a distance by a variety of sensors which reveal the presence of entities. The sensors detect and register the presence of entities coming within the span of Remote Sensing Devices. Satellite Imagery is the image obtained from a sensor placed on a satellite platform; geostationary or orbitting resolution capability of the device plays a major role in its application.

US and Russia have military satellites called the spy satellites. Though highly classified, their resolution is estimated to be in the range of submetre. Then there are commercial satellites available in the world which over the years have been improving on the resolution capability and thus enhancing their applicability. The details of the existing and future remote sensing devices in the world and their minimum resolution necessary for analyses of selected items of military interest are attached in Tables 1, 2 and 3 respectively.

The present capability of Indian Remote Sensing Satellite IRS IC/ID of 5.8 Mtrs does not allow the kind of real-time intelligence which the military is looking for. What is possible is to generate data bank of the general topography of the area of interest on our borders at various intervals. The changes in the topography can give the clues to battlefield intelligence which can then be confirmed by other means. Unfortunately, this seems to have been overlooked or not effectively coordinated in Kargil, where Pakistan was able to achieve tactical surprise. Even the electronic intelligence resources presently available with RAW seem to have overlooked gaining and updating information opposite Kargil.

A brief on satellite surveillance, strategic and tactical image analysis capability of the Indian Army are enclosed.

Remote Sensing satellite Imagery with requisite technological specifications of 1 Metre/sub Metre will qualitatively enhance the battle-field transparency. Commanders in the field will be able to base their decisions on real-time accurate information. This will greatly assist in shaping the land battle in all its phases. Satellite Imagery Intelligence supplemented by other means of intelligence gathering i.e. aerial photography, Electronic Int (EL-Int); Communication-Int (Comm-Int), Signal-Intelligence (Sig Int) using battlefield surveillance Radars (BFSR), unarmed vehicles (UAVS), aerostat balloons, aircrafts, helicopters etc will act as force multipliers in the battlefield.

Following functions will be strengthened through different phases of the land battle by suitably employing remote sensing satellite imagery capability in conjunction with other means as mentioned above:

(a) During Peace Time Border Management

(i) Building up of Data Bank required for planning of the battle i.e. geographical details, location of structures, changes if any in the topography, large scale movements etc.

(ii) Continuously updating the data base to build up the intelligence throughout the area of interest.

(b) Close to the Imminence of Hostilities

(i) Updating the Data Bank

(ii) Reconnaissance

(iii) Surveillance

(iv) Latest movement of war materials to the battle locations

(c) During the Conduct of the Battle

(i) Update Data Base

(ii) Reconnaissance

(iii) Surveillance

(iv) Major movements of enemy reserves, application of reserves.

(v) Major movements of logistic installations.

(vi) Movement and locations of major weapon systems i.e. missiles, rockets, guns, tanks etc.

(vii) Control and direction of fire power means to enhance their accuracy and reach.

(viii) Damage assessment of own fire power applications.

(d) Post Battle

(i) Updating of the Data Bank

(ii) Reconnaissance

(iii) Surveillance

It will be seen from the above that the application of multiple means of gathering intelligence, including remote sensing and satellite imagery will not only enhance the battlefield transparency but also be a force multiplier in the battlefield. What India needs is a multiple approach as suggested below:-

(a) Placing of Tech Int under the Ministry of Defence and creation of Defence Intelligence Agency (DIA).

(b) Allowing dedicated use of the existing satellite imagery resources of IRS IC/ID of 5.B Mt resolution to the defence forces.

(c) Clearance of ISRO project to acquire 1metre resolution satellites at the earliest.

(d) DRDO be asked to carry out R&D of submetre satellite devices.

(e) Acquisition and application of UAV's and Aerostat balloons for aerial photography and electronic intelligence.

(f) Acquisition of battlefield surveillance and weapon locating radars.

(g) Aerial photography with the help of aircrafts and helicopters. Very high accuracy cameras of .3 to .5 metres are available which can be mounted on helicopters and MiG-25 aircrafts to obtain latest intelligence across the borders.

(h) Acquisition of improved equipment for patrolling i.e. Night vision devices, night vision goggles, light accurate and secured means of communication, light and accurate automatic etc.

(i) Acquisition of EI Int resources to include ground, air and satellite based EL-Int.

It is also recommended that till such time the equipment suggested is procured, the existing availability of resources be placed under the defence ministry so that the real-time intelligence is available for planning and execution of operations. We need to eradicate the inadequacies noticed during the Kargil operations. The existing resources are presently fragmented and under control of different authorities denying the military the critical time response.

Appendix A

Table 1. Existing civilian and commercial remote sensing systems

Country Satellite Sensor Resolution Time Available

USA Landsat Multispectral 30 m 2-3 weeks 1972

USA TIROS Multispectral 1 m 1-2 weeks 1960

France SPOT Panchromatic 10 m 2-3 weeks 1986

Multispectral 20 m

Russia Resurs-O Panchromatic 1 m Near real-time 1988

Panchromatic 2 m

Multispectral 4 m

Russia Resurs-F/Kosmosa 2 weeks

KFA-3000b Panchromatic 2 m to 6 months 1991

DD-5c Panchromatic 2 m

KVR-1000 Panchromatic 2-3 m

KFA-1000 Panchromatic 5-8 m

MK-4 Multispectral 5-8 m

TK-350 Panchromatic 10 m

KATE-200 Panchromatic 15-30 m

Russia Mir/Priroda & 2 weeks 1991

Salyut 6.7 to 6 months

MKF-6MA Multispectral 25 m

KAP-350 Topographic 30-40 m

KFA-1000 Panchromatic 2-3 m

MK-4 Multispectral 5-8 m

Russia Almaz-1 SAR 15 m Archive Archive

EU ERS-1 & 2 SAR 30m 1991

India IRS series Panchromatic 5.8 m 1991

Multispectral 23.5 m

Japan JERS 1 & 2 SAR 18 m 2-3 weeks 1992

Japan ADEOS Panchromatic 8 m Archive 1995

Canada Radarsat SAR 10md 5-10 days 1995

a Russia launched the final Resurs-F2 # 10 spacecraft on September 26, 1995. The film return capsule landed on October 26, 1995. Film return spacecraft designated 'Kosmos' continue to be flown by Russia. Imagery from the TK-350 and KVR-1000 cameras are distributed by the SPIN-2 joint venture between Aerial Images, Inc, and SovInform Sputnik.

bCurrent Russian government restrictions prevent distribution of images with resolution better than 2 m. The KFA-3000 is reportedly capable of 0.75-1.5 m resolution images which are degraded to 2 m for distribution.

cDD-5 (which stands for digital data) is the generic term for declassified military satellite data. The DD-5 system provides 2 m resolution images covering an area of 14 x 14 km. However, camera characteristics are withheld, so data are normally supplied in georeferenced form and sold by square kilometer.

dRadarsat's synthetic aperture operates in a variety of modes, producing imagery scenes ranging from 100 to approximately 8 m in resolution.

Table 2. Future remote sensing systems

Country Satellite Sensor Resolution Time Available

USA Landsat 7 Panchromatic 15 5-7 days 1999

Multispectral 30

USA EarthWatch Panchromatic 0.82 2-3 days 1998

'QuickBird' Multispectral 3.28

USA Space Imaging Panchromatic 1 3-5 days 1998-99

IKONOS 1&2 Multispectral 4

USA ORBIMAGE Panchromatic 1 0-3 days

'Orbview-3' Panchromatic 2 or 1999

Multispectral 4 Real time

'Orbview-4' Hyperspectral 8 2000

USA Resource 21 Multispectral 10 <24 h 1999

USA RDL 'Radar 1' SAR 1 N/A late 2001

Canada Radarsat 2 SAR 3 2-7 days 2001

France SPOT-5 Panchromatic 5 N/A 2002

Multispectral 20

France Spot Image 3S Panchromatic 2.5 N/A 2003

Brazil/China CBERS Multispectral 19 N/A N/A

Japan ALOS Panchromatic 2.5 N/A 2000

Israel/USA West Indian Spaceb Panchromatic 1.5 N/A 1999

EROS 1 & 2

aFrench government and industry officials announced plans to use a technique to achieve 2.5 m resolution imagery by blending two 5 m resolution SPOT 5 images during processing.

bWest Indian Space, a joint venture by Israel Aircraft Industries and the US company Core Software Technology, will launch and operate a constellation of high resolution imaging satellites based on the Israel Ofeq-3 design.

Table 3

Minimum resolution necessary for analysis of selected items of military interesta (Resolution in bold type would be available from commercial systems due to be launched in the next five years.)

Target Detectionb General IDc Precise IDd Descriptione

Terrain 90 + 30-90 4.5 1.5

Urban Areas 60 30 3.5 1

Ports 30 15 6 3

Rail yards 15-30 15 6 1.5

Roads 10-20 5 1 0.6

Bridges 6 4.5 1.5 1

Airfields 6 4.5 3 0.3

Nuclear 5 2.5 1 0.5


Aircraft 4.5 1.5 1 0.15

Radar/radio sites 3 1-1.5 0.3 0.15

Missile sites 3 1.5 0.6 0.3

Supply depots 1.5-3 0.6 0.3 0.03

Artillery 1 0.6 0.15 0.05

aTable adapted from Dunn and Robertson [9] subsequently developed from Ann Florini [21].

bLocation of a class of units, object or activity of military interest.

cDetermination of general target type.

dDiscrimination within target type of known types.

eSize/dimension, configuration/layout, construction, count, etc.


Brief: Satellite Surveillance

The advent of the space age introduced a new dimension to acquisition of IMINT through sensors on board satellites and space stations. Surveillance satellites overfly enemy territory with impunity without the fear of being shot down (during normal course) as would be the case with aerial platforms. Vast areas can be covered in minimum time and all the advantages of aerial photography, including stereoscopy are now possible with the current sensor technology on satellites. Repetitive coverage of a desired area can be obtained at relatively low cost and more frequently.

Data from Remote Sensing satellite having applications in the field of land use, forestry, cartography, town planning etc is commercially available. Due to the low resolution, of the order 5.8 metres of IRS-IC/ID, the tactical IMINT requirements are difficult to be met.

USA and Russia have permanent ongoing programmes for surveillance from space. USA had a series of KH (Key Hole) satellites (used extensively during the Gulf War) known to have both surveillance mode called Area Search Sensors with 1-2 metre resolution and Reconnaissance Mode using Close Look Sensors with about 15 cms resolution. The image data is transmitted through digital communication link via relaying Comsats. Russia has been using the COSMOS series of surveillance satellites having short life span of about 1 month to 6 months.

Consequent to the issue of US presidential notification permitting use of High Resolution Data of (upto 1 mtr) for commercial purpose, a large number of commercial satellites are being launched and their imageries would be of high intelligence value. First in the series of these satellites was launched in September 99, by Space Imagery International, USA.

Orbits. Common orbits used for satellites are as under:

(a) Low Earth Orbit (LEO). These lie between 150-5,000 km above the earth's surface. They are either "polar" i.e. passing over the poles, or "inclined", i.e. at an angle to the earth's axis. These are favoured for general reconnaissance missions since they give the planet a wide coverage and provide better resolution for cameras. Satellites in this orbit take 90 minutes to few hours to complete one orbital path.

(b) Geostationary Orbit (GSO). These circular, equatorial orbits are at a mean altitude of 36,000 km above the earth's surface. Satellites in GSO have an orbital period of 24 hours, which makes them appear almost stationary above a fixed point above the earth's equator. Three satellites evenly placed in GSO can cover most of the planet except the polar regions. This makes them suitable for communications or early warning purposes.

(c) Sun-Synchronous Orbit. In this orbit all points at a given latitude (say in a descending pass) will have the same local mean solar time so that we can get approximately similar levels of illumination. This is the most useful orbit for remote sensing missions.

Military Satellites: Application Wise. The various types of military application satellites are photo reconnaissance (IMINT) or spy satellites orbit closest to the Earth for better viewing in terms of resolution. Electronic intelligence (ELINT) satellites in low orbit permit picking up electronic signals from various emitters. In the intermediate orbit we have the navigation satellites (NAVSAT) and ocean surveillance satellites. At an altitude of 36,000 kms we have the Geostationary orbit. COMSAT, Meteorological and Early Warning Satellites occupy this orbit.

Surveillance Satellite System. The space segment consists of the satellite itself carrying the various payloads and electronic data transmit and receive systems. The ground segment consists of the Master Control Facility for Data Reception and Processing Stations or the Earth Station. The master control facility is used for sending commands to the Space Craft for switching ON/OFF the sensors and to carry out various manoeuvers to correct the orbit. The Data Reception Station receives the data from the satellite for recording and subsequent processing to obtain the required output.

(a) Space Segment. The satellite is a compact package of technology at its most advanced stage. In addition to the payload (sensors, cameras), the satellite contains solar batteries and solar arrays for charging them, trans/receive equipment and on-board computers are also carried to perform routine housekeeping jobs.

(b) Ground Segment. The imagery data is received by the Earth Station antenna which is steerable, that is, it keeps tracking the satellite from its rise above the horizon to its setting at the ordered horizon. The data is first stored in High Digital Tapes (HDDT) and then converted to other suitable media like Computer Compatible Tapes (CCTS) for further processing. The data is processed for correcting radiometric (sensor based) distortions. The next stage is image analysis and interpretation where the human interpreters or Pls using work stations and collateral material extract intelligence. The intelligence deduced is then disseminated to users in the form of reports alongwith annotated imageries on CCTS or hard copy prints.

Spectral Bands for Satellite Imageries. Satellite sensors can image the Earth over a wide range in the Electro Magnetic-Spectrum from the Visible to the Microwave. Basically the visible region and Infra Red region are used for obtaining imageries. The Panchromatic or Black and White imagery uses the visible light region from 0.4 microns to 0.7 microns and presents the familiar black and white image and in todays context has better resolution than multispectral or colour images.

Ground Resolutions. It is defined as the minimum distance essential between objects to be discerned as two independent entities. In the eighties the 10 metre resolution of the SPOT satellite was a quantum jump in commercial imagery data availability as compared to the US satellite LANDSAT which had a resolution of 30 metres. With the availability of IRS-IC/ID 5.8 m resolution data, linear objects like roads, canals, Ditch-cum bunds (DCBs), railway lines and airfields can be detected with greater accuracy than SPOT data. With continuous monitoring a change—detection matrix can be established for specific areas of interest. This in conjunction with inputs from other intelligence sources can assist in detecting any changes or build up taking place.

Though the imageries of commercial satellites with one metre resolution will be freely available in the open market and shall be able to provide tactical intelligence, the US Govt still retains the 'Shutter Control' rights which would force the company to halt its operations during a national security crisis or an event which is detrimental to the US interest.


Strategic & Tactical Image Analysis Capability of Indian Army

Launching of Indian Remote Sensing Satellites augmented the imaging capability of all the agencies involved in the imaging field. The army too exploited the capability by having an independent organisation named DIPAC for downloading, processing and disseminating the Indian Satellite Data. This provided the army the capability of looking deep into enemy territory beyond the range which could not be thought of by strategic thinkers a few years back.

To analyse the available strategic and tactical data for our optimum use, state-of-the-art equipment were procured from the international market and are now functionally operational at all Command and Corps HQs.

The establishments raised at Command and Corps HQs are known as Imagery Interpretation Teams and are increment to the formation. These teams are equipped with state-of-the-art workstations which simplify the otherwise cumbersome and time consuming task of Imagery Interpretation. The setup comprises High Resolution Precision Scanners, Softcopy, Photogrammetry Workstations and Geographical Information systems. To top it all there are Large Format (fotorite 1040C) Systems which can convert the Digital Data into a maximum of 40"x40" format hard copy using Optical Technology. The systems are capable of handling both aerial and satellite imageries. Needless to say that the Digital Elevated Models and Stereo models created with the help of these to train strategic planners and Commanders at all levels is a great boost. This organisation with its capability will no doubt prove to be a force multiplier in intelligence acquisition and operational planning at both the Corps and Command level in the future.