Dennis B. Beringer 

Jerry D. Ball

Civil Aerospace Medical Institute

Federal Aviation Administration

Oklahoma City, OK 73125

March 2004

Final Report

This document is available to the public

through the National Technical Information

Service, Springfi eld, Virginia 22161.

 

Offi ce of Aerospace Medicine

Washington, DC 20591

DOT/FAA/AM-04/5 The Effects of NEXRAD Graphical 

Data Resolution and Direct Weather 

Viewing on Pilots’ Judgments of 

Weather Severity and Their 

Willingness to Continue a Flight 
NOTICE

This document is disseminated under the sponsorship of

the U.S. Department of Transportation in the interest of

information exchange. The United States Government

assumes no liability for the contents thereof.
i

Technical Report Documentation Page 

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. 

DOT/FAA/AM-04/5 

4. Title and Subtitle 5. Report Date 

The Effects of NexRad Graphical Data Resolution and Direct Weather March 2004 

Viewing on Pilots’ Judgments of Weather Severity and Their Willingness 

to Continue a Flight 

6. Performing Organization Code 

7. Author(s) 8. Performing Organization Report No. 

Beringer DB, Ball JD 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

FAA Civil Aerospace Institute 

P.O. Box 25082 11. Contract or Grant No. 

Oklahoma City, OK 73125 

12. Sponsoring Agency name and Address 13. Type of Report and Period Covered 

Office of Aerospace Medicine 

Federal Aviation Administration 

800 Independence Ave., S.W. 

Washington, DC 20591 14. Sponsoring Agency Code 

15. Supplemental Notes 

Work was accomplished under approved task AM-A-03-HRR-521 

16. Abstract 

A study was conducted to determine how variations in displayed NEXRAD weather data resolution interact 

with the pilot’s direct view of weather. Pilots (32) were assigned to one of four groups; 8km, 4km, or 2km 

resolution, and a baseline condition without NEXRAD imagery. Each flew the simulator from Santa Rosa, 

NM, with the intent to land at Albuquerque. Heavy precipitation moved into the area during the flight, and 

pilots were required to decide, using both the NEXRAD data and their out-the-window view, whether to 

continue or to divert to an alternate airport. Pilots spent more time looking at higher-resolution images than at 

the lower-resolution ones. Baseline- and 2km-condition pilots deferred their decisions longer than did the other 

two groups. Posttest NEXRAD image judgments reinforced the notion that higher-resolution images are likely 

to encourage pilots to continue flights with the expectation that they can fly around or between significant 

weather features. The presence of out-the-window viewable weather phenomena was seen to have a significant 

effect on how pilots regarded the NEXRAD data. 

17. Key Words 18. Distribution Statement 

NEXRAD display resolution, cockpit weather displays, 

pilot decision making, color weather displays 

Document is available to the public through the 

National Technical Information Service 

Springfield, Virginia 22161 

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price 

Unclassified Unclassified 14 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

ACKNOWLEDGMENTS

 This research was supported by the Aviation Weather Information Element (AWIN), Aviation Safety 

Program, managed by the Projects and Advanced Concepts Branch of the NASA Langley Research Center. 

Dr. Raymon McAdaragh served as the project monitor and liaison to NASA for the FAA (AAR-210).

iii

1

THE EFFECTS OF NEXRAD GRAPHICAL DATA RESOLUTION AND DIRECT

WEATHER VIEWING ON PILOTS’ JUDGMENTS OF WEATHER SEVERITY

AND THEIR WILLINGNESS TO CONTINUE A FLIGHT

Electronic displays, including both integrated instrumentation suites and add-on displays, are becoming increasingly available for use in aircraft. The multi-function 

display (MFD) is found in both situations and can display 

navigation data (terrain, cultural features, routes), traffi c 

data, and weather data. One popular form of weather data is 

the NEXRAD (NEXt-generation RADar) display, showing 

radar base refl ectivity and thus precipitation (and implied 

convective activity) graphically referenced to geographic 

location. Its popularity is not surprising given that, of the 

top 10 weather data items that pilots indicate they need 

access to (Beringer & Schvaneveldt, 2002), 3 involve 

forms of precipitation and 5 involve indices of convection/

turbulence. Additionally, the value of using an integrated 

navigation/weather graphical display over separated displays 

has been supported with performance data obtained by 

Ververs, Dorneich, Good, and Downs (2002).

Concerns have been raised that pilots may use these 

data tactically rather than strategically (see Latorella & 

Chamberlain, 2002, for a discussion), particularly when 

data are presented in comparatively high-resolution (2km 

blocks, the base resolution of the data), and there are some 

data to support this contention (Yuchnovicz et al., 2001). 

In a study reported by Latorella & Chamberlain (2002), 

participants who used a Graphical Weather Information 

System (GWIS) that included NEXRAD reported that 

a number of display features contributed to enhancing 

the display’s attractiveness for tactical use (portrayed cell 

intensities, location of precipitation and/or convective 

activity relative to aircraft position, range rings, high 

resolution – higher than the 4 km used in that study 

– and airway graphics).

NEXRAD has a number of limitations (U. of Illinois, 

1999; also see National Weather Service, 2003) that most 

pilots do not take into account in their usage of the data. 

First, the base inclination of the outgoing beam (0.5 deg) 

is such that, when combined with the curvature of the 

earth, its elevation is 14,700 ft at 124nm, reaching 50,500 

ft at 248nm. Thus, precipitation (and convective activity) 

occurring at altitudes concerning GA aircraft may not be 

registered at the greater ranges. At the other extreme, if one 

chooses the “composite” radar image, this consists of 9 or 

14 different scans from 0.5 to 19.5 degrees elevation, and 

the data thus cannot be elevation separated. Additionally, 

no data are available in the nearly 140 degrees directly 

overhead (the “cone of silence”). If precipitation was occurring at altitude directly overhead but was not reaching 

lower altitudes, it would not be detected by that particular 

radar and thus not shown in the resulting image.

The second area of concern is coverage. In most cases, 

the data are considered unreliable beyond 124nm from 

a radar facility, and in some cases the data become unreliable after 62nm. Most precipitation within 80nm is 

usually detected, with intense precipitation detected up to 

140nm, but not so for light precipitation. Geographical 

coverage is of particular concern in areas of the western 

and northwestern U.S. where radar coverage is incomplete and there is the additional problem of obstruction 

by mountainous terrain.

Third, the angular nature of the sensing sweep means 

that resolution is not uniform across any image generated 

from a single radar, and the “blocks” of data appearing 

near the periphery (248nm) are wider than those near 

the station. Thus, although nominal base resolution is 

given as 2km (and the short-range, 124nm, products 

are of this form), areas on the fringe of a radar’s coverage (and the 248nm “long-range” products @ 4km) will 

have coarser resolution.

Finally, the dynamic nature of weather phenomena 

may be diffi cult to capture in this form of data presentation. NEXRAD data received in the cockpit are always 

time-delayed from the actual observation at least 6 to 7 

minutes following the actual radar scan. This means that 

an image on a cockpit display may be as old as 12 to 14 

minutes before it is updated. This fact gives rise to the 

legitimate concern that pilots might be trying to make 

tactical decisions based upon “old” data. There is also the 

question of how much degradation is acceptable in the 

resolution of the data before pilots no longer feel that the 

displayed image is representative of the weather phenomena that they may be able to view directly through the 

windscreen. Previous studies were conducted in simulated 

zero-visibility IMC (Yuchnovicz et al., 2001; Novacek 

et al., 2001) and examined 8km and 4km resolutions, 

whereas data reported by Latorella and Chamberlain came 

from a system using only 4km resolution. Our study was 

designed to assess the effects of varying the resolution of 

displayed NEXRAD data further (down to 2km) on how 

pilots interpreted weather conditions along their route of 

fl ight and the resulting decisions made when the weather 

phenomena were directly visible. 
2

METHOD

Equipment/Participants

The sessions were conducted in the Civil Aerospace 

Medical Institute’s Advanced General Aviation Research 

Simulator (AGARS). The device was confi gured as a Piper 

Malibu, and the participants fl ew from the left seat. The 

navigation display was presented on a touch-sensitive 

12” LCD suspended from the center window post (see 

Figure 1). While this is not the anticipated location for 

the display in most applications, it was the most expedient 

positioning that retained availability of all conventional 

instrumentation in the AGARS (no integrated Primary 

Flight Display was used). It also allowed the pilot to have 

direct access for touch activation of the panel. The display 

software was Echomap (from EchoFlight) and contained 

all of the features noted earlier that would encourage 

strategic use. The display, shown in Figure 2, presented a 

moving-map representation in track-up format with the 

aircraft position shown near the bottom of the display. 

Terrain was shown in a fashion similar to VFR sectional 

charts, with a compass-rose range ring overlaid. NEXRAD 

imagery was depicted with three levels of intensity of 

returns (green for low, yellow for medium, and red for 

high). Graphical and alphanumerical navigation data were 

shown on the left-hand side of the display and included 

destination identifi er, altitude, cross-track error, ground 

speed, distance to destination, and estimated remaining 

time enroute. A cordless trackball was also available for 

the pilot’s use in activating and manipulating the moving 

map/weather display.

The algorithm used to generate the displayed 

NEXRAD image was a conservative one, and the results 

of its operation on the original source data are depicted 

in Figure 3. Starting with the native resolution of 2km, 

one can see that there are red, yellow, green, and black 

areas represented in the original data. When the 8km by 

8km area is divided into 4 blocks 4km on a side, each 

block is assigned the color of the heaviest precipitation 

occurring within that area. Thus, any 4km block that 

had a 2km red block within it becomes entirely red, and 

so on. Further, when the entire 8km by 8km area is reduced to a single block, it becomes completely red as that 

represents the heaviest precipitation within the depicted 

area. Use of this algorithm differs from either a “majority-rule” algorithm or an averaging algorithm where an 

area that was predominantly yellow, for example, would 

become all yellow when reduced in resolution, potentially 

masking an area of heavier precipitation with a resulting 

loss of data. The conservative algorithm, then, tends to 

make things look “worse” than they would be depicted if 

shown in native resolution, but does not “mask” or lose 

data depicting small areas of heavy precipitation.

Participants were 32 general aviation pilots from 19 to 

70 years of age (mean = 34.6, median = 27), with total 

fl ight times ranging from 40 to 20,000 hours (median = 

Figure 1. Weather display in the AGARS.
3

460). Each was assigned to one of four groups: 2km data 

resolution, 4km data resolution, 8km data resolution, or 

baseline (moving map but no weather overlay). A pretest 

questionnaire was used to assess each pilot’s overall fl ight 

experience (hours), by category (VFR, IFR, simulated 

IFR, total), in the last 12 months and in the last 90 days. 

They were also asked about their prior use of in-cockpit 

weather data/displays. 

Procedure

Training Training. Pilots received demonstrations of the weather .Pilotsreceiveddemonstrationsoftheweather 

and navigation page and how to zoom in and out. Each 

pilot was shown how to select an alternate destination 

for the fl ight. Participants then took off, controlled the 

aircraft, and manipulated the display for the duration of 

a short practice fl ight. They also received an autopilot 

demonstration and viewed sample NEXRAD imagery on 

the cockpit display. At the conclusion of this practice, the 

Figure 2. The EchoMap display showing sectional-style terrain representation, NEXRAD imagery, and 

graphical and alphanumeric navigation information.

Figure 3. Effect of conservative algorithm as displayed resolution is reduced (block size increased).

2 KM 4KM 8KM
4

participant returned to the departure airport and landed. 

Participants were then given the opportunity to take a 

break before continuing.

Test Flight. Participants took off from Santa Rosa 

airport in eastern New Mexico and fl ew a route at 9500 

feet proximal to Interstate 40 and direct to Albuquerque 

(ABQ). This fl ight was conducted as VFR on top after 

climbing through an extremely thin cloud layer. Each 

pilot was encouraged to use the autopilot, and all eventually did so. NEXRAD data were automatically updated 

every 6 minutes and the data were 6 minutes old when 

fi rst displayed. A sample comparison of identical source 

data displayed at the three resolutions appears in Figure 

4. Recall from the previous discussion that the algorithm 

used to convert the 2km source data to 4km and 8km 

resolutions was a conservative one, causing any larger 

block containing a 2km red source square to become red 

in its entirety. All activities were recorded on videotape 

using two cameras: wide-cockpit-shot inset and a fullscreen view of the navigation display. Flight-performance 

and eye-movement/gaze-point data were collected during 

the fl ight.

Data fl ights varied from 23 to 45 minutes in length. 

Pilots were instructed that they were the pilot in command, and were thus responsible for the safe conduct of 

the fl ight. Any decisions regarding the continuation of the 

fl ight were theirs to make. There were no circumstances 

requiring completion of the fl ight to ABQ. Afterwards, 

pilots participated in a rating session in which they viewed 

a series of slides of NEXRAD weather data comparable 

to what they had just experienced in the simulator, but at 

each of the three resolutions. Their task was to determine 

if, at any point in the series, they would opt to divert to 

a different destination. Pilots then completed a usability 

questionnaire and a posttest interview. The questionnaire 

focused on the pilots’ decisions during their fl ights, their 

recollection of specifi c weather-related details, their evaluation of the usefulness of the weather display and confi -

dence in using it, and their knowledge of the Aeronautical 

Information Manual recommendations for fl ying near 

thunderstorms. Follow-up questions were asked during 

the interview based upon responses to the questionnaire 

and experimenter observations.

RESULTS AND DISCUSSION

The primary focus of this study was the question of 

how pilots would respond to variations in the resolution 

of displayed NEXRAD data. Assessment of this response 

was based upon visual-performance data (how long they 

accessed the data), fl ight-performance data (how close 

they came to the signifi cant weather, how long they 

deferred the decision about continuing the fl ight), and 

post-fl ight display-evaluation data (how they responded 

to equivalent weather data presented at differing resolutions in a non-fl ight environment).

Visual-performance

The fl ight was divided into three segments for analysis. 

Segment 1 began at take-off, Segment 2 started when the 

pilot reached cruise altitude, and Segment 3 began when 

the pilot made a decision about continuing the fl ight 

(deviate to alternate airport, circumnavigate the storm, 

penetrate the storm, etc.), and continued until termination of the fl ight. Gaze-point videotape data were reduced 

to the length of time the pilot spent looking at each of 

the three areas of interest (moving-map with NEXRAD 

overlay, out-the-window, and other). The “other” area of 

interest was defi ned as instrumentation, radios, charts, 

and any other visually head-down locations. Time spent 

looking at each area of interest was converted to a percentage of segment-time length. Means are presented 

in Figure 5.

A 4 X 3 repeated-measures multivariate analysis of 

variance (MANOVA) was performed using percentage 

of fi xation time on each area of interest (3 dependent 

variables), where display condition was the betweengroups factor and fl ight segment was the within-subject 

factor. Pair-wise comparisons were conducted to localize 

the effects. The MANOVA revealed a signifi cant main 

Figure 4. Images from same NEXRAD source data 

presented at 2km, 4km, and 8km resolutions.
5

effect associated with group and segment [ F(9,84)=2.336, 

p<.05, and, F(5,24)=18.463, p<.001, respectively]. 

However, the effect associated with the interaction of 

group by segment was not signifi cant. Further univariate 

analyses showed signifi cant effects for segment on MAP 

[F(2,56)=26.917, p<.001], OTW [F(2,56)=11.541, 

p<.001], and INST [F(2,56)=53.611, p<.001], and 

signifi cant effects for group on MAP [F(3,28)=5.887, 

p<.001], OTW [F(3,28)=1.650, p<.001], and INST 

[F(3,28)=2.327, p<.001].

Pair-wise comparisons for segment 2 indicated the 

percentage of dwell time on the moving map was signifi -

cantly different between NEXRAD resolutions of 2km 

and 8km, and between 2km and the baseline group. No 

other signifi cant differences were observed. In Figure 5, 

the groups having NEXRAD data spent increasingly more 

time looking at the map display as resolution increased. 

The trade-off appears to be between time spent looking 

at the NEXRAD display and time looking at instrumentation and other in-cockpit features, as out-the-window 

percentages varied little between those three groups.

Flight Performance

Time to a decision, to the nearest second, was examined from notes made during each fl ight and from 

videotape records and was defi ned as the time from the 

beginning of the fl ight until a defi nitive decision was 

made regarding the continuation of the fl ight. These 

times were submitted to a one-way ANOVA, and the 

means are presented in Figure 6. A signifi cant effect of 

display resolution was found [F(3,28)=4.34, p<.02]. 

This difference is clearly between the 4km and 2km 

conditions. The trend is largely linear from the baseline 

condition (b) and decreases with increasing NEXRADimage resolution up to 4km. However, at 2km resolution, 

the delay in decisions makes a marked jump upwards. 

Attempts to “thread-the-needle” and land at ABQ were 

more prevalent in the 2km condition than in the other 

conditions, and decisions were delayed in the hope that 

the weather would change suffi ciently to allow a landing 

at ABQ. It is unclear how to explain these results given 

the comparatively small sample size and the expectation 

that the trend might be a linearly increasing function 

from 8km to 2km. It would appear, however, that earlier 

decisions on the conduct of the fl ight occurred with the 

lower-resolution presentations.

Closest-approach distance (miles) to the convective 

cells (heavy precipitation) was measured by calculating 

the distance from the simulated aircraft’s position to the 

thunderstorm’s center of mass at each point along the 

fl ight path. These values were then used to determine the 

minimum separation maintained between the simulated 

aircraft and either the small or large convective cell. These 

minimum-separation distances were then submitted to a 

one-way ANOVA with display condition as the betweengroups factor. Although no signifi cant differences were 

observed between NEXRAD display resolution types 

[F(3, 28)=2.109, p=.122)], there was a trend for closer 

approaches with higher resolutions (Figure 7).

Physical separation maintained from convective cells 

suggests that the pilots with higher resolution NEXRAD 

imagery or no NEXRAD imagery tended to fl y closer 

to the convective cells than is recommended by the 

AIM (7-1-27). It recommends “avoiding by at least 20 

miles any thunderstorm identifi ed as severe or giving an 

intense radar echo.” Note that 17 (53.2%) of the pilots 

Figure 5. Mean percentage visual dwell time by 

display condition and area of interest for flight 

segment 2. 

0.00

0.10

0.20

0.30

0.40

0.50

0.60

Map OTW Other

Area of Interest

Mean Percentage Dwell Time

No NexRAD

2 Km Resolution

4 Km Resolution

8 Km Resolution

Figure 6. Mean time (mins) to decision by 

NEXRAD display resolution (km). 

0

5

10

15

20

25

30

35

2 4 8 b

NEXRAD display resolution (km) 

(b = baseline; no NEXRAD)

Mean minutes to final decision
6

fl ew inside this recommended distance (see Table 1 for 

a further breakdown by display).

Additionally, the AIM (7-1-27) suggests not taking off 

or landing in the face of an approaching thunderstorm 

and to not attempt to fl y under the thunderstorm even 

if you can see through to the other side. However, 7 

(21.9%) pilots attempted to fl y through or under the 

thunderstorm to land at ABQ. Note that none of the 

pilots using the 8km resolution display fl ew closer than 

15 miles to the visible precipitation column (no pilots 

fell into the 10-15 mile category), whereas half of those of those 

in the 2km condition and almost half (3) of those in the 

baseline condition fl ew closer than 10 miles.

Actual diversions or nearest approach. Of those in the 

8km-resolution fl ights, all (8) diverted to an alternate 

airport. In the other groups the results were: 4km, 7 

(87.5%) diverted; 2km, 7 (87.5%) diverted; baseline, 

5 (62.5%) diverted. It is also of interest to note that 

of the 5 who continued in the simulator, 4 also voted 

to continue, at some display resolution, in the posttest 

evaluations. For our purposes of posttest categorization, we operationally defi ned strategic usage as those usage as those 

decisions/actions involving signifi cant planned changes to 

the overall route of fl ight or the selection of an alternate 

destination. In contrast, we considered highly localized 

maneuvers, heading and altitude manipulations, and any 

attempts to avoid hazards in the immediate proximity of 

the aircraft as tactical usage. 

Categorization of pilots by inferred display usage is 

shown in Table 2. Referencing the eye-movement data, 

8 (33%) of the pilots with displayed NEXRAD appeared 

to use the data display for tactical decision-making until 

they had penetrated the rain column or had fl own into 

or under the cloud model. Of those 8, 7 transitioned 

to using the direct contact view once they were in or 

under the cloud. Only 1 of those avoided cloud entry, 

tracking along the edge of the front (approximately 7 to 

8 miles from the edge of the storm) to the south until 

reaching an alternate airport (Belen). This pilot used the 

display tactically until discovering that he was going to 

penetrate the rain column, when he began using direct 

visual reference to the cell. Note that none of the pilots 

with the lowest resolution of NEXRAD exhibited tactical 

behaviors based upon display usage.

Post-fl ight interviews/questionnaires. It was evident from 

data obtained during the post-fl ight interviews that variables other than NEXRAD resolution were exerting a 

signifi cant infl uence upon pilot behavior. Discussions with 

several pilots indicated that their willingness to continue 

was based on prior experience. One particular pilot with 

foreign military experience indicated that they (foreign 

air force) regularly fl ew through this type of weather to 

complete missions. Others indicated that they were going 

0

5

10

15

20

25

2 4 8 base

Nexrad resolution (km)

Mean distance at nearest 

approach (nm)

Figure 7. Mean closest approach (km) to the 

convective cells by NEXRAD display resolution 

(b=baseline, no NEXRAD). 

Table 1. Frequency distribution of pilots by display 

resolution and proximity of approach (bold indicates 

< 20 nm).

Closest approach (d) in nm 

NEXRAD 

resolution d>25 25>d>20 20>d>15 d<10

2km 0 3 1 4

4km 3 1 0 4

8km 4 1 3 0

Baseline 1 2 2 3

Total 8 7 6 11

 Total % 25 21.9 18.8 34.3

Table 2. Display usage categorization 

(tactical vs. strategic) by NEXRAD 

resolution. 

Display usage 

Group Strategic Tactical 

Resolution 2 4 4

Resolution 4 4 4

Resolution 8 8 0

TOTAL 16 8
7

to fl y as close as possible to their destination as long as 

they had some visual contact with the ground and did not 

experience turbulence. The simulator experience for these 

individuals (those choosing to fl y close to the weather 

phenomena), then, did not present all of the cues that they 

expected as precursors of severe weather ahead. On the 

other hand, there were a large number of reports from the 

other pilots who indicated that the representation of the 

out-the-window weather was suffi cient to signal that one 

should proceed only with extreme caution; commentary 

also rooted in experience.

Post-fl ight displayed-weather ratings. The slides shown 

in the post-fl ight session depicted regular intervals along 

a course inbound to ABQ and similar to the fl ight just 

taken by the participant (the slides for the 4km-resolution 

series are shown in the Appendix; Figures A1 through 

A6). Responses of pilots to the post-fl ight series of 6 

slides for each data resolution (opting to continue after 

slide 6 was scored as 7) were submitted to a mixed-factor 

two-way ANOVA where the between-groups factor was 

display resolution fl own and the within-subject factor 

was slide-series NEXRAD resolution. The main effects 

of both display resolution fl own [F(3,84)=5.45; p<.005] 

and NEXRAD post-fl ight slide resolution [F(2,84)=7.23; 

p<.005] exhibited statistically reliable effects, but the interaction did not achieve signifi cance. The means are 

presented in Figure 8. It can be seen that increasing resolution caused the pilots, with the exception of the baseline 

group, to delay their decisions to divert in a nearly linear 

fashion. The effect of resolution fl own was also much as 

expected, with those who had fl own the higher-resolution 

displays delaying more, overall. The baseline group showed 

the greatest willingness, in the post-fl ight assessment, to 

continue to the destination.

SUMMARY

The data from this study (also reported in Beringer 

and Ball, 2003) appear to support the contention that 

higher-resolution NEXRAD images encourage pilots to 

“shoot the gap” and attempt to navigate between areas 

of heavy precipitation. It was interesting that piloting 

behavior in the fl ight simulator was at some variance with 

posttest assessments, but this may be attributable to the 

availability of the out-the-window view in the simulator 

and the ability to compare the directly viewed weather 

with the NEXRAD image. The difference between making decisions in Visual Meteorological Conditions and 

in Instrument Meteorological Conditions is not trivial, 

and these data can be thought of as a fi rst cut at this 

comparison. Many pilots commented during the posttest 

interview that their actions were in large part governed 

by the fact that they could see the weather outside. If 

one takes the posttest NEXRAD-image evaluations as 

more representative of decision making without direct 

visual reference to the weather, then there may be even 

more of a tendency to continue than was seen in the 

simulator. However, additional data in the context of a 

simulated IMC fl ight using high-resolution NEXRAD 

images need to be collected to determine to what extent 

this may be the case.

REFERENCES

Beringer , D.B. and Ball, J.D. (2003). Effects of NEXRAD 

graphical data resolution and direct weather viewing on pilot judgments of weather severity and 

willingness to continue fl ight. In Proceedings of 

the Human Factors and Ergonomics Society Annual 

Meeting, 26-30. 

Beringer, D.B. and Schvaneveldt, R. (2002). Priorities 

of weather information in various phases of fl ight. 

In Proceedings of the Human Factors and Ergonomics 

Society Annual Meeting, 6 – 10.

Latorella, K.A. and Chamberlain, J.P. (2002). Tactical 

vs. strategic behavior: General aviation piloting 

in convective weather scenarios. In Proceedings of 

the Human Factors and Ergonomics Society Annual 

Meeting, 101-105.

National Weather Service (2003). National Weather 

Service Radar Image: WSR-88D Radar FAQ’s. 

Located at http://www.srh.noaa.gov/radar/radinfo/

radinfo.html.

Figure 8. Mean post-flight slide-series diversion 

point by display resolution flown and depicted 

NEXRAD resolution on post-flight slides. 

0

1

2

3

4

5

6

8 4 2 b mean

NEXRAD resolution (km) condition that 

pilots flew (b = no NEXRAD display)

Average slide # at diversion

8 4 2

Resolution (in km) of slide series rated
8

Novacek, P.F., Burgess, M.A., Heck, M.L., and Stokes, 

A.F. (2001). The effect of ownship information 

and NEXRAD resolution on pilot decision making in the use of a cockpit weather information 

display. Springfi eld, VA: NTIS, Technical Report 

NASA/CR-2001-210845. Located at http://techrep

orts.larc.nasa.gov/ltrs/PDF/2001/cr/NASA-2001-

cr210845.pdf

University of Illinois (1999). Department of Atmospheric 

Sciences, World Weather 2010 Project, Online 

Guides. Located at http://ww2010.atmos.uiuc.edu/

(Gh)/home.rxml.

Ververs, P.M., Dorneich, M.C., Good, M.D., and 

Downs, J.L. (2002). Integrating critical information on fl ight deck displays. In Proceedings of the 

Human Factors and Ergonomics Society Annual 

Meeting, 11 – 15.

Yuchnovicz, D.E., Novacek, P.F., Burgess, M.A., Heck, 

M.L. and Stokes, A.F. (2001). Use of a datalinked weather information display and effects 

on pilot navigation decision making in a piloted 

simulation study. Springfi eld, VA: NTIS, Technical Report NASA/CRT-2001-211047. Located at . Located at 

http://techreports.larc.nasa.gov/ltrs/PDF/2001/cr/

NASA-2001-cr211047.pdf
A1

APPENDIX A

Figures A1 through A6: NEXRAD images during approach to ABQ from the east, 4km resolution. The set of 

images shows the movement of the cells in a generally northeasterly direction as the aircraft approached ABQ. 

This was one of the three sets of images used in the post-fl ight static-images assessment.

Figure A1. NEXRAD image at 100nm from ABQ. Figure A2. NEXRAD image at 82nm from ABQ.

Figure A3. NEXRAD image at 65nm from ABQ Figure A4. NEXRAD image at 49nm from ABQ.
A2

Figure A5. NEXRAD image at 32nm from ABQ. Figure A6. NEXRAD image at 25nm from ABQ.