Surveillance Balloons and Airships
Content
Surveillance Balloons: An Indian Perspective
By Udit Agrawal, GM-Operations, DSI
W
ith the ever growing threat of terrorism the needs for a more economic method of surveillance to constantly monitor large areas of concern keeps on growing. Conventional surveillance systems, both wired and wireless, become uneconomical when the subject area is a large open land mass where an overall broad perspective view is important. It is in such domains of surveillance that aerial surveillance becomes both necessary and economical. This article evaluates the feasibility of using Aerostats or tethered balloons as platforms for carrying surveillance cameras and their usefulness for both military and civil operations in an Indian perspective.
buoyancy. Their relative cheapness and ease of maintenance makes them an attractive option to be considered as a platform for carrying surveillance camera payloads high-up in the air to obtain a broader perspective view of the target area. A more common term known to us is the “airships” which are also LTA vehicles with the difference that they are not tethered, and are therefore controlled either manually or remotely and propelled forward by different means. In other words, Airships are simply the LTA replacement for heavier-than-air (HTA) vehicles like airplanes and helicopters. The third kind of LTA platforms is the Hybrid Airships which are mainly airships with a lifting body so that extra aerodynamic lift is generated as the airship propels itself through air.
Need for Aerostats in the present scenario
As the threat of terrorism grows, a common prevailing need of surveillance is to monitor large areas of concern in the civil sector with a general overall perspective rather than acquiring pin-point detail. Consider the case of an exhibition being held at Pragati Maidan Grounds in New Delhi. Take for example the International Trade Fair currently being held in Delhi, where around 30 lakh people visited the 14 day long fair. Now monitoring all these people solely through surveillance cameras mounted on poles and exhibition walls, becomes a very tedious an uneconomical task. The relative efficiency still remains low. The Delhi Police is using around 850 armed personnel along with 4 companies of paramilitary forces, all aided by 50 CCTV cameras installed at critical areas. Though this is a fairly tight security installation, the level of situational awareness remains low. For example, if we have to track a trouble-maker running away from a scene, owing to the large crowd of people, the task is fairly difficult. The task however becomes relatively easy if we have a broader perspective view of the area using an aerially mounted camera. Again, if for some reason, a stampede occurs, situational awareness gained
Aerostats, also sometimes referred to as captive balloons are tethered Lighter-than-Air (LTA) platforms filled with either Helium or Hydrogen which helps them stay aloft in air due to
through a broader perspective helps tremendously by letting us know the areas where people are running to, allowing the security forces to know the specific points where they should mobilize the security personnel to stop the stampede. The major advantage of aerial surveillance is to provide a broad perspective view of the area from air, which leads to increased situational awareness and hence faster and more efficient surveillance. The concept of broader perspective becomes obvious in some situations like border and coastal surveillance. The Indo-Pak border is one of the longest high-tension border in the world. The border stretching 3323km is constantly under vigil and major sectors like the Jammu sector in Kashmir and Gujarat sector have already been fenced. However, despite the fencing, the infiltration still continues. Any attempt to have a round-the-clock constant video surveillance through cameras mounted on poles is unfeasible because of elaborate wiring and network requirements. On the other hand, cameras mounted on aerostats can cover a much larger area making the whole idea feasible. Aerostats can also be used as platforms for terrestrial radars, which will constantly map the surface and detect infiltration. Such Radars mounted on tethered aerostats are already in use along the southern US border along Mexico and Caribbean. The program known as TARS (Tethered Aerostat Radar System) is one of the most successful LTA programs around the world successfully and efficiently tracking cross-border migration and drug traffickers.
be cheap and take less time for deployment. Some current examples are the REAP (Rapid Elevated Aerostat Platform) used by US army in Iraq and the RAID (Rapid Aerostat Initial Development) used in Afghanistan. These aerostats carry sensor suits and cameras (day/night vision) that help enhance the mission effectiveness by providing the army with knowledge of enemy troop’s location and strategy. Besides surveillance, aerostats also provide a very effective platform for telecommunication antennas as well as broadband access points. The elevated position of antennas can significantly enhance their range and decrease the cost of establishing a communications network. TCOM LP (USA) already manufactures a series of aerostats ranging from 15m to 71m sizes for Telecommunication purposes for both the US government and the US Navy.
Balloons and Aerial Surveillance: a brief History
Long before fixed-wing heavier than air (HTA) vehicles entered the world of aviation, balloons were being used to get a view of the earth from the sky. Since World War-I, when we still struggled to make an airplane that could cross the Atlantic, the German Hindenburg were flying from Germany all the way to USA carrying passengers. Aerostats like the French Caquot balloons and German Drachen balloons) were used in World War-I, as aerial observation posts, which by most can be called as the first attempt examples of Aerial Surveillance. The use of balloons for various aerial applications was fairly common in the early twentieth century when the fixed-wing HTA technology was still premature. However, as the HTA technology developed, the interest in balloons decreased causing a major stall in balloon development. This stall lasted up until the last quarter of the twentieth century when their relatively cheap cost of operation and easy deployment compared to the HTA counterparts revived the interest in balloons.
Another military use of aerostats is during battles, where an aerostat system can provide increased situational awareness and battlefield knowledge allowing them to properly plan their moves with respect to their enemy. Such a system needs to
The interest in aerostats re-developed in the late 1960s when their advantages over HTA vehicles were realized. Another reason for the sudden rebirth of interest in balloons is attributed to the advent of computers. Contrary to what most
people may think, tethered-vehicle flightdynamics is much more complex than a regular aircraft. In a paper written in the early twentieth century by Bairstow et al, the complete sixdegree of freedom equations for balloon stability were derived. The resulting equations were so complex, that they were conceived unsolvable unless simplified by various assumptions. The engineers did however solve some simple cases, and the solutions were presented in the form of tables, which were anyhow very complicated to be of any real use. Though, some attempts were made to solve simplified cases, it was not until the mid 70s that the first reasonable solutions for such equations were obtained. In a historic paper in that time by Delaurier (who also happens to be the author’s mentor), the stability of tethered vehicles was revisited with a new and more logical approach and the problem solved using the current computational methods available at that time. Once the advantages were realized, Aerostats have been used for various military applications like border security (TARS), enhancing battlefield situational awareness, coastal surveillance, telecommunications, aerial platform for scientific instrument testing, aerial platform for weather prediction instruments, terrestrial mapping and for holding up large-array radiotelescopes.
Recently, the potential of aerostats in the civil surveillance markets have been realized, and several companies across the globe have taken up initiatives to develop small aerostats for civil surveillance purposes. Certain key advantages that aerostats enjoy are: 1. Cheaper 2. Safe 3. Rapid deployment in rural or non-urban areas allows for quick and inexpensive establishment of communication networks. 4. Easy to deploy and maintain. 5. Require minimum crew-training for handling, making it easier to incorporate into the already established surveillance infrastructure. 6. Provides a broad perspective/view of target area for video surveillance. 7. Aerostats can be used as a platform for Radars, IR/optical sensors, and other sensor equipments. 8. Can be used as cheap low-altitude telecommunications relay platforms for purposes like broadband communication and wide area networks (WAN). 9. Bigger more sophisticated aerostats flying at an altitude of 15000m can be used as cheap low-maintenance geostationary satellites. The aerostats are being made in USA, Israel and Europe for application in the civil markets for surveillance and telecommunication purposes. All these aerostats however are very expensive and their designs are not tailored for the Indian market. Unlike many countries, India’s extreme and diversified tropical climate presents many challenges to aerostat envelope design. The extremely high May-June temperatures produce highly turbulent weather at low altitudes, which makes it essential to evaluate the stability of the design in high turbulence. Besides, since the Indian market is very price-conscious which makes it apparent that cost-reduction becomes imperative. For example, aerostat winches are relatively expensive, and their use should be eliminated wherever possible. Certain key issues that will have to be kept in mind while choosing an aerostat for the Indian market:
An Indian Initiative
1. 2. 3. 4.
5.
6. 7.
8.
Cheap Durability of envelope in tropical continental weather. Durability of envelope against the severe monsoons (extreme humidity). The tropical weather generates strong turbulent gusts during noon-time, and so the aerostat should be designed to withstand such gusts. Good stability in high-wind conditions and the ability to not lose altitude in such winds. The balloon itself should be easy to manage and replace when required. The electronic equipment should be weatherproof, and the gimbal system to mount these electronics should be gyrostabilized. It is very essential that the parts should be easily accessible as unavailability of spare parts can be a major setback.
of civil and military surveillance. As India’s economy continues to grow, and as long as the threat of terrorism continues to prevail, it is only obvious that we should adopt this new technology sooner. However, an Indian initiative in this field is definitely required as the Indian climate presents great challenges which can only be met if the design has been optimized for such conditions.
In the military scenario, the Indian government realized the potential of aerostat as a platform and has sanctioned the purchase of Aerostat mounted Radar Surveillance systems for the Indian Air force. Two such Radars have been placed in Gujarat and Punjab. But the IAF has expressed the need for at least ten more such systems. Besides surveillance, aerostats also provide a very good platform for mounting telecommunication and broadband equipment. Access points enclosed in a weather-proof box can be hanged from a series of aerostats in a mesh network topology providing an efficient and economical city-wide broadband network. Similarly, Television and radio transmitters can be mounted on an aerostat and elevated to big heights providing a cheap and efficient way of providing these facilities in cities. This saves us the cost of erecting expensive TV-towers, which are still not as high as aerostats causing lower reception. Cellular phone companies can also use aerostats as platforms for mounting their transmitting antennas instead of land-based transmitters. Similarly various other applications of aerostats can be thought of from communication’s perspective.
Conclusion
With the current trend, it is apparent that aerostats will soon become an indispensable part
By Udit Agrawal, GM-Operations, DSI
W
ith the ever growing threat of terrorism the needs for a more economic method of surveillance to constantly monitor large areas of concern keeps on growing. Conventional surveillance systems, both wired and wireless, become uneconomical when the subject area is a large open land mass where an overall broad perspective view is important. It is in such domains of surveillance that aerial surveillance becomes both necessary and economical. This article evaluates the feasibility of using Aerostats or tethered balloons as platforms for carrying surveillance cameras and their usefulness for both military and civil operations in an Indian perspective.
buoyancy. Their relative cheapness and ease of maintenance makes them an attractive option to be considered as a platform for carrying surveillance camera payloads high-up in the air to obtain a broader perspective view of the target area. A more common term known to us is the “airships” which are also LTA vehicles with the difference that they are not tethered, and are therefore controlled either manually or remotely and propelled forward by different means. In other words, Airships are simply the LTA replacement for heavier-than-air (HTA) vehicles like airplanes and helicopters. The third kind of LTA platforms is the Hybrid Airships which are mainly airships with a lifting body so that extra aerodynamic lift is generated as the airship propels itself through air.
Need for Aerostats in the present scenario
As the threat of terrorism grows, a common prevailing need of surveillance is to monitor large areas of concern in the civil sector with a general overall perspective rather than acquiring pin-point detail. Consider the case of an exhibition being held at Pragati Maidan Grounds in New Delhi. Take for example the International Trade Fair currently being held in Delhi, where around 30 lakh people visited the 14 day long fair. Now monitoring all these people solely through surveillance cameras mounted on poles and exhibition walls, becomes a very tedious an uneconomical task. The relative efficiency still remains low. The Delhi Police is using around 850 armed personnel along with 4 companies of paramilitary forces, all aided by 50 CCTV cameras installed at critical areas. Though this is a fairly tight security installation, the level of situational awareness remains low. For example, if we have to track a trouble-maker running away from a scene, owing to the large crowd of people, the task is fairly difficult. The task however becomes relatively easy if we have a broader perspective view of the area using an aerially mounted camera. Again, if for some reason, a stampede occurs, situational awareness gained
Aerostats, also sometimes referred to as captive balloons are tethered Lighter-than-Air (LTA) platforms filled with either Helium or Hydrogen which helps them stay aloft in air due to
through a broader perspective helps tremendously by letting us know the areas where people are running to, allowing the security forces to know the specific points where they should mobilize the security personnel to stop the stampede. The major advantage of aerial surveillance is to provide a broad perspective view of the area from air, which leads to increased situational awareness and hence faster and more efficient surveillance. The concept of broader perspective becomes obvious in some situations like border and coastal surveillance. The Indo-Pak border is one of the longest high-tension border in the world. The border stretching 3323km is constantly under vigil and major sectors like the Jammu sector in Kashmir and Gujarat sector have already been fenced. However, despite the fencing, the infiltration still continues. Any attempt to have a round-the-clock constant video surveillance through cameras mounted on poles is unfeasible because of elaborate wiring and network requirements. On the other hand, cameras mounted on aerostats can cover a much larger area making the whole idea feasible. Aerostats can also be used as platforms for terrestrial radars, which will constantly map the surface and detect infiltration. Such Radars mounted on tethered aerostats are already in use along the southern US border along Mexico and Caribbean. The program known as TARS (Tethered Aerostat Radar System) is one of the most successful LTA programs around the world successfully and efficiently tracking cross-border migration and drug traffickers.
be cheap and take less time for deployment. Some current examples are the REAP (Rapid Elevated Aerostat Platform) used by US army in Iraq and the RAID (Rapid Aerostat Initial Development) used in Afghanistan. These aerostats carry sensor suits and cameras (day/night vision) that help enhance the mission effectiveness by providing the army with knowledge of enemy troop’s location and strategy. Besides surveillance, aerostats also provide a very effective platform for telecommunication antennas as well as broadband access points. The elevated position of antennas can significantly enhance their range and decrease the cost of establishing a communications network. TCOM LP (USA) already manufactures a series of aerostats ranging from 15m to 71m sizes for Telecommunication purposes for both the US government and the US Navy.
Balloons and Aerial Surveillance: a brief History
Long before fixed-wing heavier than air (HTA) vehicles entered the world of aviation, balloons were being used to get a view of the earth from the sky. Since World War-I, when we still struggled to make an airplane that could cross the Atlantic, the German Hindenburg were flying from Germany all the way to USA carrying passengers. Aerostats like the French Caquot balloons and German Drachen balloons) were used in World War-I, as aerial observation posts, which by most can be called as the first attempt examples of Aerial Surveillance. The use of balloons for various aerial applications was fairly common in the early twentieth century when the fixed-wing HTA technology was still premature. However, as the HTA technology developed, the interest in balloons decreased causing a major stall in balloon development. This stall lasted up until the last quarter of the twentieth century when their relatively cheap cost of operation and easy deployment compared to the HTA counterparts revived the interest in balloons.
Another military use of aerostats is during battles, where an aerostat system can provide increased situational awareness and battlefield knowledge allowing them to properly plan their moves with respect to their enemy. Such a system needs to
The interest in aerostats re-developed in the late 1960s when their advantages over HTA vehicles were realized. Another reason for the sudden rebirth of interest in balloons is attributed to the advent of computers. Contrary to what most
people may think, tethered-vehicle flightdynamics is much more complex than a regular aircraft. In a paper written in the early twentieth century by Bairstow et al, the complete sixdegree of freedom equations for balloon stability were derived. The resulting equations were so complex, that they were conceived unsolvable unless simplified by various assumptions. The engineers did however solve some simple cases, and the solutions were presented in the form of tables, which were anyhow very complicated to be of any real use. Though, some attempts were made to solve simplified cases, it was not until the mid 70s that the first reasonable solutions for such equations were obtained. In a historic paper in that time by Delaurier (who also happens to be the author’s mentor), the stability of tethered vehicles was revisited with a new and more logical approach and the problem solved using the current computational methods available at that time. Once the advantages were realized, Aerostats have been used for various military applications like border security (TARS), enhancing battlefield situational awareness, coastal surveillance, telecommunications, aerial platform for scientific instrument testing, aerial platform for weather prediction instruments, terrestrial mapping and for holding up large-array radiotelescopes.
Recently, the potential of aerostats in the civil surveillance markets have been realized, and several companies across the globe have taken up initiatives to develop small aerostats for civil surveillance purposes. Certain key advantages that aerostats enjoy are: 1. Cheaper 2. Safe 3. Rapid deployment in rural or non-urban areas allows for quick and inexpensive establishment of communication networks. 4. Easy to deploy and maintain. 5. Require minimum crew-training for handling, making it easier to incorporate into the already established surveillance infrastructure. 6. Provides a broad perspective/view of target area for video surveillance. 7. Aerostats can be used as a platform for Radars, IR/optical sensors, and other sensor equipments. 8. Can be used as cheap low-altitude telecommunications relay platforms for purposes like broadband communication and wide area networks (WAN). 9. Bigger more sophisticated aerostats flying at an altitude of 15000m can be used as cheap low-maintenance geostationary satellites. The aerostats are being made in USA, Israel and Europe for application in the civil markets for surveillance and telecommunication purposes. All these aerostats however are very expensive and their designs are not tailored for the Indian market. Unlike many countries, India’s extreme and diversified tropical climate presents many challenges to aerostat envelope design. The extremely high May-June temperatures produce highly turbulent weather at low altitudes, which makes it essential to evaluate the stability of the design in high turbulence. Besides, since the Indian market is very price-conscious which makes it apparent that cost-reduction becomes imperative. For example, aerostat winches are relatively expensive, and their use should be eliminated wherever possible. Certain key issues that will have to be kept in mind while choosing an aerostat for the Indian market:
An Indian Initiative
1. 2. 3. 4.
5.
6. 7.
8.
Cheap Durability of envelope in tropical continental weather. Durability of envelope against the severe monsoons (extreme humidity). The tropical weather generates strong turbulent gusts during noon-time, and so the aerostat should be designed to withstand such gusts. Good stability in high-wind conditions and the ability to not lose altitude in such winds. The balloon itself should be easy to manage and replace when required. The electronic equipment should be weatherproof, and the gimbal system to mount these electronics should be gyrostabilized. It is very essential that the parts should be easily accessible as unavailability of spare parts can be a major setback.
of civil and military surveillance. As India’s economy continues to grow, and as long as the threat of terrorism continues to prevail, it is only obvious that we should adopt this new technology sooner. However, an Indian initiative in this field is definitely required as the Indian climate presents great challenges which can only be met if the design has been optimized for such conditions.
In the military scenario, the Indian government realized the potential of aerostat as a platform and has sanctioned the purchase of Aerostat mounted Radar Surveillance systems for the Indian Air force. Two such Radars have been placed in Gujarat and Punjab. But the IAF has expressed the need for at least ten more such systems. Besides surveillance, aerostats also provide a very good platform for mounting telecommunication and broadband equipment. Access points enclosed in a weather-proof box can be hanged from a series of aerostats in a mesh network topology providing an efficient and economical city-wide broadband network. Similarly, Television and radio transmitters can be mounted on an aerostat and elevated to big heights providing a cheap and efficient way of providing these facilities in cities. This saves us the cost of erecting expensive TV-towers, which are still not as high as aerostats causing lower reception. Cellular phone companies can also use aerostats as platforms for mounting their transmitting antennas instead of land-based transmitters. Similarly various other applications of aerostats can be thought of from communication’s perspective.
Conclusion
With the current trend, it is apparent that aerostats will soon become an indispensable part
