GISMO NavigationJohn Sonntag

EG&G Technical Services, Inc.31 January 2007

Navigation Techniques Two navigation tools

available Soxmap

Used for May 2006 GISMO Standard Twin Otter tool Visual aid for flight crew Best for following curved path

Course Deviation Indicator (CDI)

Will be used for 2007 GISMO Can couple to aircraft steering Good repeatability for long

straight lines

23 May 2006 Mission Plan Flight plan was out-and-

back Thule to Camp Century,

then southeast along 18 May 1999 ATM/KU flight track

Inbound leg offset 25 m to south of outbound

Constant 10,000' pressure altitude

060523 Steering Performance (1)

Red dots: outbound leg Blue dots: inbound leg Black lines are the target lines Target lines are separated by 25

m Top panel is at 300 km along-

track from Thule, bottom at 400 km

Inbound/outbound separation in top panel is ~35 m

Inbound/outbound separation in bottom panel is <=175 m

060523 Steering Performance (2)

060523 Steering Performance (3)

24 March 2006P-3 Steering Error with CDI

Lessons Learned from May 2006

2006 GISMO flight used Soxmap / Twin Otter combination Configuration more suitable for outlet glacier

work Steering within +/-50m, could be better

2007 GISMO flights will use CDI with P-3 Better repeatability for straight flight lines Consistent 25-m separation still difficult to

maintain More info: atm.wff.nasa.gov; click

“Aircraft Navigation”