JLENS reintroduces aerostats to the battlefield

by Craig Fleming

The Army Transformation Campaign Plan and Army/Joint Vision 2010 objectives are driving development of innovative advanced-technology solutions to communications problems. The Warfighter Information Network-Tactical and other systems promise to provide commanders unhindered and flexible availability of communications and information-systems data.

The communications-relay platform is a key component in the new architecture. Traditional mast-mounted antennas are limited in range and constrain the commander to available terrain. An ideal solution would be a mobile mountain that is easy to climb, easy to set up and easy to move. This seemingly improbable concept exists today in the form of an aerostat.

The Army has successfully used aerostats in World War I and many other campaigns. These helium-filled vehicles are tethered to trailers for simple operation and transportation.

The modern-day aerostat is part of the Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System. (Call it JLENS for short.) You may have seen the JLENS aerostat, since the JLENS project office � in cooperation with BAE Systems Canada Inc. � demonstrated our small tactical-aerostat system (following figure) at the 2000 Signal symposium.

JLENS tactical aerostat 93d Signal Brigade soldiers and JLENS contractors prepare the tactical aerostat for flight at the Signal Center's symposium last year.

In this article, I�ll provide Signaleers:

An overview of JLENS and aerostats;
A review of the symposium demonstration; and
A preview of aerostats� future use in Signal missions.

JLENS overview

The JLENS project office is based at U.S. Army Space and Missile Defense Command, Huntsville, Ala. We�re chartered to develop and field a low-cost, elevated netted-sensor system. The Army�s Air Defense Artillery School provides key operational requirements and has specified communications-relay capability as a secondary mission. Signal experts are also influencing the operational-requirements-document development.

JLENS uses a 71-meter aerostat platform for the cruise-missile-defense radars being developed. The aerostat can reach heights up to 15,000 feet above ground level with a 4,000-pound payload. Part of the JLENS development effort is focused on enhancing the system�s mobility and transportability.

JLENS also owns a smaller-size aerostat system. This system is an excellent candidate for dedicated communications missions. The aerostat can raise a 150-pound payload to 1,000 feet AGL.

Operating characteristics of aerostats depend on base altitude and temperature. For example, on a cool day stationed at sea level, the aerostat will fly higher than on a warm day stationed at 4,000 mean sea level.

In the following figures, the first figure depicts line-of-sight coverage for a traditional mast-mounted antenna. From Augusta, Ga. (the location of the Signal symposium demonstration), about 2,800 kilometers squared of "battlespace" is covered. The second figure shows LOS coverage for the tactical aerostat at 1,000 feet AGL. The aerostat covers about 31,000 km2, more than 10 times the mast-mounted antenna coverage.

LOS for antenna 25 feet AGL LOS representation for an antenna 25 feet above ground level.
LOS for aerostat 1,000 feet AGL LOS representation for an aerostat 1,000 feet above ground level.

A battlefield-communications network supported by an aerostat significantly increases the commander�s movement flexibility. As MG Pat Cavanaugh stated in his Chief of Signal Comments in the Spring 2001 Army Communicator, "Objective-force commanders must be free to lead without being tied to a geographically static command post." Aerostats are a key platform that commanders must use to execute this requirement.

JLENS has successfully participated in many exercises and demonstrations with the small aerostat system to illustrate the aerostat�s contribution to the warfighter. We�ll return to the Signal Center at Fort Gordon, Ga., for the 2001 Signal symposium.

Signal symposium review

I�ve mentioned our presence at the 2000 Signal symposium, where we provided the small tactical aerostat for BAE Systems Canada to conduct a high-data-rate on-the-move demonstration. The following objectives were achieved:

Seamless connectivity between high-capacity LOS (AN/GRC-245) and Joint Tactical Radio System (VRC-99) radios;
Videoconference between fixed station and mobile vehicle;
Collaborative whiteboarding and file exchange;
Internet protocol telephone connectivity among all stations; and
Electronic mail and Internet connectivity among all stations.

BAE provided the equipment and architecture shown in the figure below. The aerostat enabled three types of communications among the ground stations:

Over-the-air HCLOS to HCLOS;
Over-the-air VRC-99 to VRC-99; and
Through-fiber-optic-tether Ethernet to Ethernet.
High-data-rate on-the-move architecture demonstration High-data-rate on-the-move architecture for the Signal symposium demonstration.

Voice, video and data were transmitted simultaneously to the various stations. The demonstration illustrated that high-quality information can reach forward-deployed units to increase situation awareness.

Future preview

As I said, JLENS will participate in the 29th Signal Symposium Nov. 26-30. We�re developing payload plans in coordination with the Signal Center�s combat-developments directorate. This year�s effort will be structured to quantify the aerostat�s capabilities vs. traditional communications-relay solutions.

This effort is vital because, as JLENS project manager COL Mary Fuller pointed out, "Manpower and equipment requirements for communications coverage in the battlefield area of operations are significantly reduced. The small tactical-aerostat platform, as well as the 71-meter aerostat cruise-missile-defense platform, will significantly enhance the commander�s ability to tailor the battlefield and obtain information superiority."

JLENS is actively seeking opportunities to prove its benefits and fulfill its mission requirements. We�re teaming with the Battle Command Battle Lab (Gordon) and the Signal Center�s DCD. We�re also coordinating plans to team with other programs to enable evaluation of the aerostat�s effectiveness with other communications and intelligence technologies. Cooperation between the air defense and Signal communities will result in meeting objective-force requirements with a practical, low-cost, maneuverable capability.

Mr. Fleming is a test engineer in the JLENS project office, Huntsville. He holds a bachelor�s degree in mechanical engineering and master�s degree in manufacturing-systems engineering from Louisiana Tech University.

Acronym QuickScan
AGL � above ground level
DCD � directorate of combat development
HCLOS � high-capacity line-of-sight
JLENS � Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System
Km2 � kilometers squared
LOS � line of sight

dividing rule

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