Huygens Ground Track Determination:A Comparison of DWE and DISR Results

R. Dutta-Roy, B. Rizk, S.W. Asmar, D.H. Atkinson,

M.K. Bird, M.W. Bushroe, E. Karkoschka,

E.A. McFarlane, C. See, M.G. Tomasko,

and the DWE and DISR Teams

DPS Cambridge - Poster 45.09Wednesday, 7 September 2005

DWE Zonal Winds

26 min gap70 s gaps (VLBI)

166.5

167

167.5

168

-11.5

-11

-10.5

2000 3000 4000 5000 6000 7000 8000 9000

Probe Longitude and Latitude HistoriesFit to Observed Image Points

Eas

t L

on

git

ud

e (o

)L

atitud

e ( o)

Mission Time (sec)

Predicted Landing Site:

167.644o East Longitude

-10.356o Latitude(DTWG Offset)

-10.4

-10.38

-10.36

-10.34

-10.32

-10.3

0

5

10

15

20

167.58 167.6 167.62 167.64 167.66 167.68

Image-Derived Probe Ground Trackadj. to DWE Offset and HASI Altitude Profile

Fit

ted

Lat

itu

de

(o)

Altitu

de (k

m)

Fitted Longitude (o)

DISR Panorama Mosaic – 4 km

ground track(with altitude)

DWE-DISR Zonal Speed

DWE-DISR Ground Track

450 mDWEgap

Huygens Ground Track: Summary

• Mean zonal speed: 67.3 km/h (18.7 m/s)

• Mean meridional speed: 1.4 km/h (0.4 m/s)

• Zonal drift (from start): 166 3 km (3.75)• Latitude drift (from 55 km): 3.5 km (0.078)• Landing Site Latitude: 10.340.17 South

• Landing Site Longitude: 192.340.24 West

Excellent DWE/DISR agreement from 0-55 km