tion, Tech- 
ical simula- 
rom space- 
1; SPIE Vol. 
ars: Digital 
y 
ereo Scan- 
ly, WAOSS 
ereo Scan- 
ly, WAOSS 
KINEMATIC GPS PROFILES AND NAVIGATION IN ANTARCTICA 
A.Capra*, F.Radicioni **, L.Vittuari* 
* D.LS.T.A.R.T. (Topografia), Università di Bologna. Italy 
** Istituto di Ingegneria Ambientale, Università di Perugia. Italy 
Commission I, Working Group 2. 
KEY WORDS: GPS, navigation, surveying, monitoring, method, dynamic. 
Abstract 
GPS data collection started at Terra Nova Bay 
Station (Antarctica) since the 1988-89 in the 
framework of the Italian Antarctic Research 
Program (PNRA). During the past expeditions a 
number of tests of GPS kinematic were made. 
The GPS data were collected under various 
operational conditions and for different targets, 
such as glacier movements monitoring, 
kinematic GPS controlled aerophotogrammetry, 
execution of long range Antarctic traverses, ship 
navigation tracking control, etc. 
Those GPS kinematic applications showed 
peculiar aspects by the point of view of data 
processing, due to ionospheric disturbances and 
satellite configuration at high latitude. 
Here are described the different kinematic GPS 
experiences and are presented some results. 
1. Introduction 
The very high ionospheric disturbance and the 
NAVSTAR GPS constellation characterised by 
low satellite elevation, create serious problems 
in signal acquisition and data processing. 
The strong influence of the severe ionospheric 
conditions became evident during GPS static 
data elaboration. This effect has been overcame 
through the employment of idoneous post 
processing strategies, and receivers 
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development. On the contrary, the problem, still 
maintains problematic aspects for kinematic 
applications, so in order to obtained the required 
precision it is not possible to apply an automatic 
procedure, but it is necessary to analyse step by 
step limited block of data. 
Various applications required different levels of 
accuracy and precision, ranging from different 
tens of metres for navigation purposes to few 
centimetres for glacier bodies monitoring 
through profiles comparison. 
Precision of few metres level are achievable 
without serious problems using code smoothing 
techniques also in Antarctica, the critical 
aspects pointed out for high accuracy 
applications where the presence of ionospheric 
cycle slips often invalidate fixed ambiguities 
determination. This aspect becomes evident 
already after a distance of 5 km between master 
and rover receiver (Vittuari, 1994). 
2. Airborne kinematic GPS positioning 
Different application for GPS assisted 
aerophotogrammetry and geophysical survey 
purposes were made in Antarctica. In this case 
the required accuracy is related to the purposes 
of the survey and ranging from few metres to 
few decimetres. 
During the 1993-94 expedition eleven missions 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B1. Vienna 1996