Helifilms

The strong relationship between Axsys Technologies and Troll Systems has resulted in a technological partnership from which our customers benefit in many ways. One of these is the way in which all of our Cineflex products are enhanced by the ability to transmit live pictures to the ground, this being a need throughout the diverse roles that both the Cineflex V14 and the MS2T are called upon to perform.

When considering downlinks as an adjunct to your Cineflex purchase we will recommend that you have a direct conversation with Troll, who are the experts in this field. This guide is therefore just intended to be an overview of the subject and to suggest some of the factors you will need to consider.

The first decision you will have to make is whether you want to transmit images in High Definition or Standard Definition. Of course we all want the very best, but there is always a question of cost versus benefit. In roles such as law enforcement, border security and other forms of military or government surveillance this decision will usually be dictated by the standard operating procedures of the particular organisation, how much autonomy is given to the aircrew, and what form of on-board recording media is being used. Pictures transmitted to the ground will usually be used for situational awareness and force command and control. On board the aircraft will always be the best place to carry out identification and to gather evidentiary material.

The second piece of information we will need from you is the frequency you wish to operate on. Troll produce equipment for all the standard frequencies between 2GHz, and 7GHz, but bespoke equipment can also be produced for frequencies outside that range. Different countries’ regulatory authorities take different views on the use of each of these frequency bands and in many cases the frequency will be dictated by pre- existing arrangements within your country. The equipment you order will be designed specifically for the frequency you choose. If you are currently unable to answer the question about the frequency you expect to be allocated then Troll can help with country-specific research on the subject.

The third factor you will need to consider is the range you require. Of course the answer will always be “as far as possible”. Downlinked RF must always follow a clear line-of-sight so your local terrain will have an effect. Typically most systems will comfortably achieve 40- 50 kms. In perfect conditions distances as far as 160kms have been attained, but the height that the helicopter would have to fly to achieve that would be operationally impractical.

With those three principal decisions made you will be ready to begin selecting your hardware under the guidance of the experts at Troll.

The Skylink SP is the antenna most usually selected for the role of Law Enforcement as there is often competition for space on the underside of a police helicopter. However, if range for the downlink is the overriding consideration, and if lower frequencies can be used, then one of the following two antennas, designed more for the television broadcast industry, would be the answer.

The option of SD or HD is available in all four of the above antenna types and they can each be controlled through the Microwave Control option incorporated into the HDU 900, the power house of the Cineflex control system. Depending on the aircraft type, the choice of frequency, the choice of antenna and the range required, a typical aircraft downlink installation will cost between $65,000 and $140,000.