Helicopter Virtual Environment and Navigation Studies at NPS

Since 1998, helicopter navigation has been an active area of study at the Naval Postgraduate School. The helicopter navigation studies have been part of a larger effort to study navigation, training and virtual environments. This page provides a brief summary of the highlights from the work conducted to date and describes work in progress. Related work can also be found at VIRTE page (VE Helo) and the FAA Helicopter GPS SNI pages

Exploring the Feasibility of the Virtual Environment Helicopter System (VEHELO) for Use as an Instructional Tool for Military Helicopter PilotsWalter J. Kulakowski, MAJ, USMC September 2004 pdf


The requirement for low-level navigation flight conducted between 200 and 500 feet above ground level is something unique to the military helicopter pilot. Each novice helicopter pilot is introduced to this skill early and in a limited number of flights or flight hours. A low situational awareness (SA) is historically noted among the novice pilots during their first few flights within this flight regime. To that end, this thesis continues with the work conducted earlier to develop a trainer that places the pilot in an immersive and familiar cockpit environment for training through the use of chromakeyed technology as employed in the Virtual Environment Helicopter System (VEHELO). The pilot will then be able to learn and exercise required piloting tasks and multi-place aircraft communications as authentically and as meticulously as in actual flight. The focus of this thesis is to continue validation of the ChrAVE/VEHELO system. This will be accomplished by comparison of data obtained from data collected by pilots flying the ChrAVE and flying the actual aircraft during initial navigational training flights. Additionally this thesis will attempt to show that the latest version of the system has a previously unrecognized ability to improve pilot performance. The system is capable of teaching novice pilots the important skill of Crew Resource Management (CRM) and the appropriate communication skills. The original Chromakey Augmented Virtual Environment (ChrAVE) helicopter flight simulation system was developed to substantiate the feasibility of having embedded trainers for helicopters. Both the ChrAVE and VEHELO are comprised of commercial off the shelf (COTS) equipment in a mobile wheeled box. To determine the effectiveness of the ChrAVE as an instructional tool, the opinions of pilots and pilot instructors will be collected for analysis. The subject pilots will be tasked with numerous realistic piloting tasks. Empirical data will be collected and evaluated according to the low-level navigation performance thresholds set forth by Marine Medium Helicopter Training Squadron 164 (HMMT-164) which is the CH-46E Model Manager.

Visual Simulation of Night Vision Goggle Imagery in a Chromakeyed, Augmented Virtual Environment Del Beilstein, CPT, USA June 2003 pdf


Despite data indicating more human error accidents occur during NVG flight than in any other flight mode, there are very few simulation tools available to aviators at the unit level that aid them in learning or practicing NVG flight tasks. This thesis examines the potential for a Chromakeyed Augmented Virtual Environment (ChrAVE), consisting only of Commercial-Off-The-Shelf (COTS) hardware, to be used as an NVG flight training platform. It also examines whether or not physically-based light calculations are necessary to produce adequate visual representation of simulated NVG imagery. Twelve subjects performed simulated low-level NVG flight navigation tasks in the ChrAVE. Treatments included questionnaires, vision tests, variation of the physics-based component of the NVG imagery, and performance of an evaluation task that compares standard thresholds between day and NVG navigation. Analysis of data and subject feedback indicate that the ChrAVE has potential as an NVG flight training device, and that physically-based calculations may not be necessary to achieve simulated NVG imagery that is adequate for training. The data also supports the existence of a substantial difference in the subjective evaluation standard between navigation performances based on flight condition.

Visual Field Requirements for Precision Nap-of-the-Earth Helicopter FlightLoren Peitso, LCDR, USN


Helicopter flight simulation visuals must display terrain for high altitude flights as well as flights within few feet of the terrain. Currently high altitude visuals are well understood and supported, but extremely low altitude visuals are not. Terrain relief and texturing that appears convincing at high altitudes is drastically oversimplified at NOE altitudes, eliminating critical visual cues. Without adequate visual cues, simulated NOE flight is pointless, or worse, may induce negative training transfer. Too much visual complexity will overburden a real-time 3D graphics pipeline adversely affecting frame rate and usability. This thesis attempts to identify the minimal visual requirement for NOE helicopter simulation, thus enabling future simulator and trainer designers to make informed decisions regarding design criteria tradeoffs.Based on a task analysis of hovering over an unprepared landing site, critical cues were implemented in a fixed base helicopter flight simulator and tested on ten military helicopter pilots. Results indicate that a critical density of visually complex three-dimensional vegetation in combination with high-resolution terrain textures enabled experienced military helicopter pilots to accurately determine helicopter motion and make control corrections. Hover performance was degraded using lower vegetation densities and significantly degraded using just high-resolution textures.

Exploring a Chromakeyed Augmented Virtual Environment (ChrAVE) for Viability as an Embedded Training System for Military HelicoptersMark Lennerton, CAPT, USMC June 2004 Power Point Presentation pdf

Once the military helicopter pilot deploys aboard a naval vessel he leaves behind all training platforms, short of the actual aircraft, that present enough fidelity for him to maintain the highest levels of readiness. To that end, this thesis takes a preliminary step in creating a trainer that places the pilot in an immersive and familiar environment to exercise myriad piloting tasks as faithfully and as rigorously as in actual flight. The focus of this thesis it to assess the viability of an chromakeyed augmented virtual environment (ChrAVE) trainer embedded into a helicopter for use in maintaining certain perishable skills. Specifically this thesis will address the task of helicopter low-level land navigation. The ChrAVE was developed to substantiate the viability of having embedded trainers in helicopters. The ChrAVE is comprised of commercial off the shelf (COTS) equipment on a transportable cart. In determining whether a system such as the ChrAVE is viable as a laboratory for continued training in virtual environment, the opinion of actual pilots that were tasked with realistic workloads was used.
Additionally, empirical data was collected and evaluated according to the subject pool’s thresholds for acceptable low-level navigation performance.

Prototype of embeded chromakey-based helicopter training system

The Effect of GPs on Helicopters and Simultaneous Non-Interfering Operations Work in progress

The FAA is interested in improving use of airspace. One area of investigation is helicopter SNI (Simultaneous Non-interfering) procedures. Since these routes were primarily been developed before the widespread use of GPS navigation systems they are not designed to take advantage of the – presumably improved – navigation performance. This project is designed to quantify the improved navigation accuracy GPs adds, determine how pilots use GPS in flight and finally, propose, evaluate and test alternative SNI procedures. Current information can be found here.


Helicopter missions are never defined as “… successful navigation to and return from a location.” Navigation, in and of itself, is not the mission – it is, however, a skill that all helicopter pilots are expected to master in order to function as pilots. Navigation is a means to an end.
Helicopter operations, being inherently expensive and unforgiving of mistakes, are prime candidates for such innovative training techniques as virtual (3-D) fly-throughs. This thesis, as a logical extension of previous research, seeks out ways to enhance current training methods for urban helicopter navigation using state-of-the-art-technology. Using empirical data from pilot surveys and controlled experiments, principles can be formulated to determine the level of computer graphics fidelity necessary for helicopter crews to conduct a virtual flight in an urban setting that is a credible, effective tool in preparation of an actual flight. This research does not seek a replacement method of training helicopter terrain navigation – pilots must still be taught the fundamental skills of map interpretation and terrain association using conventional training techniques. However, it is the intent of this research to explore methods of enhancing and supplementing site-specific helicopter navigation training through the transfer of spatial knowledge from the virtual world to real-world applications.

An Interactive Virtual Environment For Training Map-Reading Skill In Helicopter PilotsTim McLean, CAPT, USMC September 1999


Currently, Student Naval Aviators are trained to interpret 1:50,000 scale contour maps by watching VHS videotapes. These tapes show a helicopter moving about twice its normal speed over desert terrain. Primarily due to the lack of interactivity in these videos, students often make mistakes very early in the videotaped flight. The helicopter does not stop until the tape is over, hence, the training evolution quickly becomes useless because students usually make mistakes during the first minute of the tape and are unable to recover or to learn from those mistakes.Based on a previous study at the Naval Postgraduate School, a training system that utilizes virtual environment technology was developed that is compliant with the Information for the 21 st Century (IT-21) initiative. The system was built using a Windows NT /Intel (Wintel) based computer along with three 24-inch monitors to train the tasks of map interpretation and terrain association. This desktop system was fielded at Helicopter Antisubmarine Squadron 10 (HS-10) for experimentation.
Results of this experiment indicate that student pilots who received VE training performed the navigation task better in the helicopter than students who received only conventional training.. Also, an IT-21 Wintel based computer is capable of rendering a graphically intensive multi-monitor application at frame rates suitable for training

Helicopter Terrain Navigation Training Using A Wide Field Of View Desktop Virtual EnvironmentJoe Sullivan,LCDR, USN September 1998


Helicopter terrain navigation is a unique task — training for this task presents unique challenges. Current training methods rely on dated technology and inadequately prepare pilots for real-world missions. Improved training specifically tailored to address the unique needs of the helicopter community that capitalizes on recent improvements in desktop virtual environment (VE) technology could substantially improve the training process and reduce training costs.Based on the input of subject matter experts in current helicopter terrain navigation training techniques and VE technology, such a system was developed and tested on student pilots performing real-world tasks. A desktop VE that presented a simple to control and learn, interactive fly-though of a terrain model was used to augment conventional training at Helicopter Antisubmarine Squadron Ten (HS-10). Results indicate that flight time for students that received VE training was more productive than for students that received conventional training. This work justifies the next logical step; fielding a system on a long-term basis as a squadron asset. This system would provide improved training for the helicopter community and an invaluable source of research data for the Naval Postgraduate School.

Four screen display used for helicopter terrain navigation training..

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