Positioning problems of disaster communications-low Earth orbit satellite-based least squares method

Author

Nakajima, Isao ; Juzoji, Hiroshi ; Nawaz, Muhammad Naeem

Author_Institution

Nakajima Lab., Tokai Univ., Kanagawa, Japan

fYear

2005

fDate

23-25 June 2005

Firstpage

253

Lastpage

258

Abstract

We have studied on the current Emergency Position Indicating Radio Beacon (EPIRB) of COSPAS-SARSAT. An orbiting satellite receives a signal (406 MHz) sent from earth, and the ground position is calculated from data on at least three Doppler shifts, using the least squares method. However, we can point out some problems that are investigated as follows; 1) The multipath and blocking caused by sea waves and tides adversely affect data communications. 2) Fluctuations in crystal oscillations caused by induced acceleration resulting from waves/tides and temperature change adversely affect the frequency stability of transmission signals, eventually leading to positioning errors. 3) Others. So we feel that a new system should be developed to replace it.

Keywords

Doppler shift; Earth orbit; disasters; least mean squares methods; satellite ground stations; tides; waves; 406 MHz; COSPAS-SARSAT; Doppler shifts; EPIRB; Earth orbit satellite; crystal oscillation; data communication; disaster communication; emergency position indicating radio Beacon; frequency stability; ground position; least squares method; positioning errors; positioning problem; sea waves; tides; transmission signals; Acceleration; Data communication; Doppler shift; Earth; Fluctuations; Least squares methods; Ocean temperature; Orbital calculations; Satellite broadcasting; Tides;

fLanguage

English

Publisher

ieee

Conference_Titel

Enterprise networking and Computing in Healthcare Industry, 2005. HEALTHCOM 2005. Proceedings of 7th International Workshop on

Print_ISBN

0-7803-8940-9

Type

conf

DOI

10.1109/HEALTH.2005.1500452

Filename

1500452