SHORT-RANGE MICROWAVE DOWNLINKS

Transcription

1 SHORT-RANGE MICROWAVE DOWNLINKS Helicopter Video downlink systems for law enforcement are becoming a necessity. Access to real time live video gives ground based personnel the information they need to make tactical and manpower decisions immediately during high-risk incidents. General This BMS short range system is recommended for transmission of live video to ground based personnel who are directly involved in the incident of interest. The helicopter transmit antenna is omni directional with moderate gain characteristics. It transmits in 360 and does not require pointing. Downlinks require line of sight between the transmit antenna and the receive antenna. The helicopter utilzes a TAA-101 antenna actuator which deploys the antenna well below the aircrafts camera ball, spot light, and skids giving clear line of sight transmission to the receive sites. screen monitor making it easily transportable between vehicles. Alternately, the system may be integrated into most existing on board camera/recorder systems. The receiver is recommended wherever localized sharing of real time video from an airborne observer is desired. The SKYLink battery operated hand held receiver weighs just 5.5 lbs, has a neck strap and is perfect for taking into the eld. The portable receiver may be powered using an internal battery, cigarette lighter socket, or another vehicle 12 VDC power port and uses a small lightweight antenna. The receiver system can be fully self-contained with a dedicated 5.6 at

2 > Short-range Microwave Downlinks > Helicopter Equipment > Ground Equipment Broadcast Microwave Services, Inc. reserves the right to make changes for the purposes of technical improvement All rights reserved Dec 2011 Broadcast Microwave Services, Inc. Corporate Headquarters Crosthwaite Circle Poway, CA US Phone: +1 (858) Fax: +1 (858) BMS Europe Schwalbacherstr Heidenrod-Kemel GERMANY Phone: Fax:

3 MEDIUM-RANGE MICROWAVE DOWNLINKS Helicopter Video Downlink Systems for Law Enforcement are becoming a necessity. Immediate access to real time live video gives ground-based supervisors the information they need to make tactical and manpower decisions during high-risk incidents. General The medium range video downlink combines a low cost omnidirectional helicopter transmit system with the easy to use Silhouette GPS steerable antenna system. This combination provides a system capable of covering up to a 50 mile radius. Helicopter Equipment Figure 1 shows the aircraft equipment comprising a BMT75 series video transmitter and a TAA-101 actuator system. An HCP-50 or HCP-100 control panel turns the transmitter on and off, sets the frequency and power level, and has an LED indicator indicating the transmitter is on frequency and operating. The control panel also controls the deployment of the TAA-101 actuator system. The TAA-101 is typically mounted on the helicopter skid. When the aircraft is in the air, the actuator can be deployed down, lowering the omni antenna below the skids and any other underside obstructs, to provide a clear transmission path. The omni directional antenna is typically a BMA-6-O, 5-6 dbi gain antenna, that transmits the signal a full 360, eliminating aircraft antenna pointing. A GTF-300 is often used, to provide the GPS position of the aircraft to the ground, to point the ground antenna at the aircraft. The GTF-300 includes a GPS receiver and an FSK modem to format the GPS data for sending to the ground. The GPS receiver can either use its own antenna, or we can provide a splitter to share an existing GPS antenna. Options include video scrambling, down look antenna, receive capability, relay capability and 12 VDC operation. The complete aircraft system typically weighs 18 lbs (<9 kgs) and draws 4.5 Amps at 28 VDC. Ground Equipment The ground equipment is comprised of a Silhouette GPS Steered Antenna, BMR120/220 Series Receiver and SCU-136 Controller. The directional antenna is continuously steerable through 360 degrees using the front panel controls of the SCU-136 controller. The Logictrack feature of this system uses GPS position information from the helicopter, sent to the ground via the microwave link, to point the Silhouette Steerable Antenna back towards the helicopter. The BMR120 /220 Series Receiver receives the video signal and GPS data from the helicopter. If the system is to be located at a remote location then an MC5 PC based software program works as a Master Controller and allows the systems to be controlled remotely via telephone line, ber or microwave. Receiver Site Selection Microwave transmission is achieved using line of sight (LOS) paths. Ideally, site selection should be made so as to allow the greatest coverage of the area of operation. The antenna may be located on an existing tower or building, typically the higher the better for reliable operation. AC power must be available. Mounting lower on the tower is permissible but leaves the antenna susceptible to the shadowing effect of the steel tower when trying to operate through the tower.

4 > Medium-range Microwave Downlinks > Helicopter Equipment > Ground Equipment Broadcast Microwave Services, Inc. reserves the right to make changes for the purposes of technical improvement All rights reserved Dec 2011 Broadcast Microwave Services, Inc. Corporate Headquarters Crosthwaite Circle Poway, CA US Phone: +1 (858) Fax: +1 (858) BMS Europe Schwalbacherstr Heidenrod-Kemel GERMANY Phone: Fax:

5 LONG-RANGE MICROWAVE DOWNLINKS Helicopter Video Downlink systems for Law Enforcement are becoming a necessity. Immediate access to situational video gives ground-based staff the information they need to make tactical and manpower decisions during high-risk incidents. General The long range video downlink combines a GCA-4L steerable transmit antenna system on the helicopter with a Silhouette GPS steered receive antenna system on the ground. The antenna systems are operator friendly, using GPS data to point the two antennas correctly. This combination provides a system capable of covering a radius of 100 miles. Helicopter Equipment As shown below nearly all system components are contained within the GCA-4L antenna pod. The directional antenna is gyro-stabilized and continuously maintains a bearing set by the user. A GPS receiver allows the high gain antenna to automatically point to a known ground location such as a remote comms site. Options include voice and data transmission, video scrambling, 12 VDC operation, downlook antenna and receive capability that allows simultaneous transmit and receive operation for signal relay through the helicopter. The GCA-4L system and associated equipment weigh approximately 40 pounds and draws 6 amps at 28 VDC. Ground Equipment The ground equipment is comprised of a Silhouette GPS steerable Antenna, BMR220 Series Receiver and SCU-136 Controller. The directional antenna is continuously steerable through 360 degrees using the front panel controls of the controller. The Logic Track feature of this system uses GPS position information from the helicopter, sent to the ground via the microwave link, to point the Silhouette Steerable Antenna back towards the helicopter. The BMR220 Series Receiver receives the video signal and GPS data from the helicopter. If the system is to be located at a remote location, then an MC5 based software program works as a Master Controller allowing the systems to be controlled remotely via telephone line, fiber, or microwave. Receive Site Selection Microwave transmission is achieved using line of sight (LOS) paths. Ideally, site selection should be made so as to allow the greatest coverage of the area of operation. The antenna may be located on an existing tower or building, typically the higher the better for reliable operation. AC power must be available. Mounting lower on the tower is permissible but leaves the antenna susceptible to the shadowing effect of the steel tower when trying to operate through the tower.

6 > Long-range Microwave Downlinks > Helicopter Equipment > Ground Equipment Broadcast Microwave Services, Inc. reserves the right to make changes for the purposes of technical improvement All rights reserved Dec 2011 Broadcast Microwave Services, Inc. Corporate Headquarters Crosthwaite Circle Poway, CA US Phone: +1 (858) Fax: +1 (858) BMS Europe Schwalbacherstr Heidenrod-Kemel GERMANY Phone: Fax: