The United States Air Force core missions of rapid global mobility and global strike share a need for timely and accurate wind knowledge for successful mission execution. Uncertainty in the winds between aircraft and ground can cause large errors in many of these operations. To mitigate threat risk and improve fuel efficiency, Air Force operations are desired at higher altitudes which further enhance error in mission accuracy from wind uncertainty.
Aircraft Mission planning involves the creation of a flight plan based on multiple inputs including threats, targets, terrain, weather, aircraft performance capability, and configuration. It is an essential task that must be completed prior to any fixed or rotary wing aircraft sortie, says USAF. The planner must have the ability to plan weapon, cargo, passenger, and/or fuel delivery, calculate fuel requirement and assess the route based on known enemy threat location and type. Mission planners must be able to optimize and de-conflict flight routes with other aircraft; review, print and brief the plan; download pertinent flight information to on-board aircraft avionics; and, conduct dynamic/in-flight replanning as applicable
To support the need of Air Mobility Command (AMC) to improve airdrop precision, AFRL is exploring different technologies to measure the wind between aircraft and ground for better Computed Air Release Point (CARP) calculations. The Air Force Research Laboratory (AFRL) has been researching groundbased and airborne Lidar and Radar sensors to provide real-time wind profiles to improve aiming solutions for airdrop payloads and gunship munition trajectories.
QinetiQ North America (QNA) has secured a contract to supply its wind profiling portable radar (WiPPR) technology to the US Air Force Life Cycle Management Center (AFLCMC). The $3m contract requires the company to design and build a prototype airborne WiPPR unit based on its ground-based WiPPR system.
QinetiQ wins USAF contract for airborne WiPPR technology
WiPPR is simple to operate and is functional even in inclement weather. The system’s high-resolution wideband RADAR is capable of sensing horizontal and vertical wind speeds at altitudes up to 5 km with range bins as small as 3 m. Compared to similar RADAR systems, WiPPR is considerably smaller, uses less power and requires minimal setup and maintenance, says QinetiQ. It measures real-time wind information to support guided, ballistic and personnel airdrop operations . It also measures wind information for meteorological application in forecast models
QNA emerging markets vice-president Bob Polutchko said: “Airborne WiPPR will provide the airdrop aircraft an organic capability to characterise the air mass and execute a ‘single-pass’ precision resupply of troops in contact. “This capability will reduce the exposure of aircraft and aircrews to enemy countermeasures.”
The WiPPR is said to provide near real-time precision wind measurements to allow C-130 and C-17 aircrews to airdrop critical supplies accurately and quickly to US ground forces in austere locations. The WiPPR data increases the accuracy of forecast models and decreases miss distance during guided, ballistic and personnel airdrop operations, QNA stated.
Besides airdrops, WiPPR can also be used for a wide variety of applications including mission planning and data gathering.
AFRL demonstrations to evaluate LIDAR and RADAR for wind measurements
AFRL has carried out multiple demonstrations for both unguided Precision AirDrop (PAD) and Gunship Wind Sensing (GWS) programs using Lidar and Radar to measure their effectiveness in measuring wind between aircraft and ground and produce timely wind profiles for algorithms that calculate corrected aim points.
AFRL has developed Weather Integrated Stochastic Simulation (WISS) and the operational mission planner Consolidated AirDrop Tool (CAT), to perform analyses on how wind Lidar/Radar can improve PAD accuracy. WISS is a physics-based model that computes an impact point for a given release point using planned and actual winds. CAT is an AirDrop planning system used by aircrews to produce a release point based on pre-mission information (e.g. forecast, bundle, and aircraft data) and updated winds from dropsondes when available. Windpacks and dropsondes are small parachuted sensors that are thrown from the aircraft to measure wind from aircraft to ground by tracking its horizontal displacement while falling via Global Positioning System (GPS).
AFRL’s conclusions from demonstrations can be summarized by the following:
• Forecast wind values perform poorly when looking at a specific time and place and should not be the sole source of wind data for any given drop.
• Forecast wind data at high altitudes are commonly accurate and can give a good overview of general winds in the area, thus forecasts should not be discarded
• In complex terrain, winds at lower altitudes tend to be more turbulent. This turbulence creates an even larger uncertainty in the forecast wind values thus increasing the need to accurately measure and report local low altitude winds.
• A single sounding from any source (dropsonde, weather balloon, Lidar) may not be a good representation of the winds through which a payload may pass during descent. Multiple soundings should be used for a CARP calculation to increase confidence in the solution.
• If multiple soundings are available from a single location the variance from these soundings can be used to quantify bundle dispersion and miss distance.
• No single location, by itself, regardless of distance from the drop zone (DZ), can guarantee an accurate representation of the winds over the DZ. Thus, when using an airborne sensor, winds measured along the flight path do not always represent winds at the DZ.
• Winds measured closer to the DZ are not necessarily more representative than those measured farther away.
• Sensor range is affected by power, atmospheric conditions, and scanning geometry. Wind Lidar and Radar depend on particulates in the air to create a signal feedback. At higher altitudes the amount of particulates diminishes especially above the planetary boundary layer.
• Higher powered Lidars tended to perform better at longer ranges, except in cases of precipitation which, at times, blacked out the Lidar, but allowed for a stronger signal and longer range for the Radar.
USAF Joint Precision Airdrop System-Mission Planner (JPADS-MP)
This project continues the development of a Joint Precision Airdrop System-Mission Planner (JPADS-MP) Phase I capability in conjunction with the Army.
JPADS provides a planning and execution capability for DoD airdrop requirements. It is the primary airdrop mission planning and execution system for all ballistic airdrop missions as well as precision guided airdrops that are required when the mission profile or surface-to-air threat assessment warrants a high-altitude and/ or standoff precision delivery.
It enables high-altitude, precise airdrop delivery to forward ground forces, mitigating surface-to-air threats, reducing risk of Improvised Explosive Devices (IEDs) and insurgent attack on ground convoys. JPADS allows the warfighter to consider weather, terrain, aircraft capabilities, threat, etc., to accurately deliver payloads to combat and other friendly forces.
The Consolidated Airdrop Tool (CAT) is the key JPADS-MP software deliverable. It will increase the accuracy of airdrop mission planning by improving aircraft, payload, and chute specific calculations along with weather analysis visualization tools specifically adapted for airdrop.
Future initiatives are designated to achieve automation of airdrop planning and execution to reduce task saturation in the cockpit and support AMC’s objective of moving to a two man cockpit. These efforts include, but are not limited to the ability to automatically receive and use real-time winds in any location, calculation of a release point and airdrop in a single pass, the ability to conduct real-time objective area analysis to calculate probable damage estimates and execute dynamic re-tasking, the ability to conduct post-drop assessments, implementation of new technologies (e.g. Service Oriented Architecture (SOA) Touch Screen environment.
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