Air Force Research Laboratory

Transcription

1 Air Force Research Laboratory Lidar Wind Sensing for Improved Precision Airdrop and Gunship Wind Sensing 27 Jun 2016 Integrity Service Excellence Wesley Jones InfoSciTex AFRL RQQD 1

2 AFRL PAD FCC and MS&A In 2010, Air Mobility Command identified Precision Airdrop (PAD) as their #1 Capability Gap Need for aerial delivery superb accuracy extended offset distances higher altitudes single pass October 2010 PAD Flagship Capability Concept (FCC) Systems Engineering Study Identified 3 Areas for R&D: Computed Air Release Point (CARP) Weather profiling, update, navigation, execution Payload Release Exit, release, configuration, crew coordination Payload Execution Deceleration, descent, flight path, impact PAD FCC 7 Focus Areas: Bundle Tracking Humanitarian Airdrop Systems Forced-Exit Delivery Systems Airdrop Performance Modeling and Simulation IR Imaging Human Effectiveness Wind Sensing (RADAR/LIDAR) Precision Airdrop Wind Sensing Gunship Wind Sensing 2

3 Operational Precision Airdrop High Altitude Characteristics Drop altitude driven by threat Forecast winds up to 12 hours old Low cost parachutes have inconsistent performance Large payload dispersion Improved wind observation requires two passes Dropsonde provides updated wind observation Unknown wind is a major contributor to Airdrop accuracy and precision error 3

4 Precision Airdrop Vision High Altitude Single-Pass, high-altitude, low cost parachutes, ballistic resupply 4

5 Typical Wind Observation Sources Balloon travels downwind of release point (payload from upwind) Dropsonde provides single profile soda straw of wind and can be missing data. Requires two-pass mission Release Point 1 Mile Balloon Path Bundle Path Dropsonde Path Drop Zone Outline Drop Altitude 18,000 ft MSL 13,600 ft AGL 5

6 Phase 1 UNCLASSIFIED Precision Airdrop (PAD) Demonstrations Phase 2 Phase 3 Phase 4 Ground Demonstration September 2012 Dugway Proving Ground, UT 2 Lidar, 2 Radar Weather balloons, Tethersonde, Towers Ground based systems supported by Aircraft January 2013 Dugway Proving Ground, UT 5 Lidars, 1 Radar Airdrop Bundles, Dropsondes, WindPacks, Weather Balloons Heavy Snowfall followed by clear air conditions Ground based systems supported by Aircraft October 2015 Yuma Proving Grounds, AZ 1 Radar, 1 Lidar- both systems developed specifically for PAD Airdrop Bundle, Weather Balloons, Dropsondes, WindPacks Airborne Lidar Demonstration Early 2017 Location TBD Aircraft TBD Downward-looking Lidar sensor with conical scanner 6

7 Wind Profiles System 1 System 2 System 3 Balloon Different systems were generally all in good agreement Measured range, resolution, and integration time varied between systems High powered lidar performed best at measuring winds at higher altitudes Snowfall enhanced radar s ability to measure wind Snowfall blocked measurement from all lidar systems After snow, very clear air conditions occurred creating difficult conditions for all systems. DropSonde Bundle Lidar Forecast 7

8 AFRL Procured Wind Sensors PAWS3 Airdrop-modified systems 1 Lidar (WPAD- Lockheed Martin WindTracer) and 1 Radar (WiPPR- Qinetiq) were selected for Airdrop development Systems were ruggedized, miniaturized, enhanced, and operated specifically for Airdrop needs Parameter Minimum Altitude Maximum Altitude Vertical Resolution Wind Speed Accuracy Scan angle / accuracy Size Weight Power Start-up Update Rate Operability / Availability Laser & Human Safety System Requirement 150 m (~492 ft) (T), 30 m (~98 ft) (O) 5500 m (~18,000 ft) < 72 ft +/- 1 m/s (+/- ~2.2 mph) 30-degree half-angle +/- 0.5 degrees (60-degree cone nominal) 57 Width x 35 Depth x 51 Height < 1100 lbs < VAC ± 5V 47Hz to 63Hz 30-minute turn-on from standby condition sec update rate. Data latency < 3 minutes Autonomous operation // 24/7 availability MIL-STD-1425A (tailored) & MIL-STD-1472G (tailored) Laser Safety Eye safe with unaided viewing and skin safe (Class 1M) 8

9 Gunship Wind Sensing 9

10 Operational Gunship Overview Goal: Improve First Shot Accuracy 30mm cannon Current Method Tweak- Shots fired at offsite location to calibrate and minimize gun system errors Determines wind and gun deltas Winds may vary significantly between tweak site and employment area System updated in attack orbit with real-time round impact points to further refine solution Future Goals Increase gunfire (first-shot) accuracy through quickly acquiring new wind values Increase safety during gunfire Allow weapons delivery from higher altitudes Increased first round accuracy = reduced fratricide risk/ unintended consequences 10

11 Gunship Demonstrations Phase 1 Phase 2 Phase 2A Phase 3 Ground Demonstration April 2014 Dugway Proving Ground, UT Systems set on hilltop looking at a downward angle into the valley Instrumented LOS Multiple vendors Airborne demonstration on Navy Twin Otter September 2014 Dugway Proving Ground, UT LMCT WindTracer System-fixed look angle 6k-12k feet MSL Ground Elevation ft A/C speed ~120 kts Airborne demonstration on commercial C-130A October 2015 Owens Valley, CA LMCT WindTracer System fixed look angle 10k-17.5k feet MSL Ground Elevation k ft A/C speed ~240 kts Gunship-representative speeds and altitudes Live-fire demonstration on AC-130W Fall 2016 Location TBD Non-Integrated Sensor will be stand alone Wind adjustments based on Lidar will be post processed. 11

12 Wind Location Lidar wind data from the different orbit points (OP) was used to analyze the effects of using winds at a site other than the target site. This is similar to what happens operationally with winds being different between tweak site and target area. KMER OP2 Combat Tweak Site OP3 Attack Orbit Site OP2 OP3 36 OP2 OP4 31 OP3 OP2 14 OP3 OP4 62 OP4 OP2 100 OP4 OP3 126 Miss Distance (ft) OP4 Winds can vary greatly between tweak site and target area. Use of tweak location winds can lead to large miss distances in the new target area. 12

13 Orbiting Difficulties Highly variable aircraft roll angles during an orbit can create problems for a fixed scanner when calculating vector winds Profiles from consecutive orbits were consistent thus did not suffer from the variable roll. Hdg, Pitch, Roll (deg) Heading/10 Pitch Roll _ UTC Hour MSL Altitude(kft) 13

14 Sector Size How much angular diversity is required for a good wind profile? Large vertical wind speed is an indicator of bad or noisy vector velocity estimation. This variability was driven by spatial wind speed variations along the orbit path. A minimum of 180-degree orbit is recommended in order to get good average winds over the entire orbit 14

15 Conclusions Conclusions Multiple demonstrations have successfully shown that Lidar/Radar technology can effectively measure in situ winds to support Airdrop and Gunship missions. Both ground-based and airborne Commercial-Off-The-Shelf wind-profiling systems have been demonstrated Ability to use a fixed beam Airborne Lidar to measure winds in a Gunship application has been demonstrated Work is still on-going on how best to implement this technology into current or future Air Force Operations. 15

16 Operational Challenges Operational System Challenges: Functional Range (enable lookahead) Cost, SWAP (Size Weight, and Power) Installation (location & federated) CONOPS (Single Pass, no significant change to tactics) Data Resolution Integration Time All weather system needed to capture wind profiles in clear air and in cloudy conditions (hybrid Radar and Lidar) 10 min t=-10min Slowdown Speed (140 KIAS) 9 min 8 min 7 min 6 min 5 min 4 min 3 min 2 min 1 min GL 30 Nm 20 Nm 10 Nm 6 Nm 0 Nm DZ Operational Mission Challenge: Balancing system parameters, tactical constraints, operational security, aircrew safety, with system requirements within available timeline 16

17 Questions? 17