the use of high-gain antennas on airborne platforms auvsi cascade chapter auvsi spring symposium...
TRANSCRIPT
The Use of High-Gain Antennason Airborne PlatformsAUVSI Cascade Chapter AUVSI Spring Symposium 2013Seattle, WA17 April 2013
Presented by: Tom Perkowski, Director of SalesWritten By: Jeff Hopkins, Chief Technology Officer
www.TrollSystems.com
Overview & Objective
• Interoperability• Types of Data Links• Objectives &
Challenges with LOS
• Improving the Link• Omni v. Directional• Operational Costs• Summary
2
Objectivedescribe the
advantages of using high-gain
tracking antennas on airborne platforms to
improveperformance of LOS data links
Interoperability
• Interoperability working together
• Limit the use of RF spectrum to that required for your mission
• Improve availability higher yields from mission
“Both Iraq and
Afghanistan produced examples of an environment
where nearly anything that was
turned on interfered with something
else”Fulghum, David. "Untangling the
Electromagnetic Traffic Jam." Aviation Week. N.p., 28 June 2011
3
Types of Data Links
• LOS digital microwave link with omni or directional antenna
• OTH low, medium and high resolution satellite link with tracking antenna
Focus of talk – increase capability & lower mission cost
4
LOS = Line of SightOTH = Over the
Horizon
Objectives for LOS Data Links1. Easy to deploy2. High data rates3. High availability4. Low latency5. Local control – closed system6. No hourly cost
5
Challenges with LOS Data Links• Availability / breakup due to:
a. Local interferenceb. Vehicle blockingc. Signal faded. Lowering data rate to overcome a, b, &
c above
6
Link Budget
7
TxPower +
Loss inAir
(HUGE)+Antenna
Gain +AntennaGain > Receiver
Threshold
Sample Equation for UAV’s
1W30dBm
+ -84 dB+ 4 dBi + 4 dBi > Avg.-90 dBm
-46 dBiLoss -6dB when mileage
is doubled
D (NM)Loss (dB)
1 -60
2 -66
4 -72
8 -78
16 -84
32 -90
64 -96
128 -102
Double Wattage 3dB increase
WGain
(dBm)1 30
2 33
4 36
8 39
16 42
32 45
How Do We Make it Better?
8
Things we cannot control
● Terrain● Intrinsic path loss● Receiver threshold
Things we can control Limiting Factors
Transmitter PA Power
● Aircraft power ● Weight● Heat ● Multipath● Interference with other users
Ground Antenna Gain ● Size & Weight● Set-up time
Airborne Antenna Gain● Complexity● Certification issues● Drag
Notional Improvement
9
In the AirHigh Gain
On
th
e G
rou
nd
Om
ni
Hig
h
Gain
Omni
Omni v. Direction
al
10
Directional Advantages• Increase range
with same power• Minimize
interference interoperability• Increase data rate
by minimizing multipath effects
Operational Cost Considerations• How often do you lose link? • LOS links often used for real-time data
– get it now or it’s lost• Interference: your mission is successful
– your colleague’s mission is not• Multipath forces a reduction in data
rate lower quality image
• What is total capital investment?• What is average hourly cost?• What is the cost to missing that one
critical moment?11
Summary
• Realistically only three variables can be controlled:– Transmitter antenna gain– Transmitter power– Receiver antenna gain
• Omni directional best for short range, low data rate applications
• Directional tracking best for long range, high data rate applications
• Cost of data loss is measureable
12
Contact Information
13
Jeff HopkinsChief Technology OfficerPhone: +1 661 702-
m
Corporate Office24950 Anza Drive Valencia, CA 91355+1-661-702-8900+1-661-702-8901 Fax
Thomas PerkowskiDirector of SalesPhone: +1 661 702-8900
x141VO: +1 619 617-4215Cell: +1 661 [email protected]
om
Virtual Office6377 Estrella AvenueSan Diego, CA 92120Download whitepaper at (case sensitive):
http://db.tt/pnosUgx9