Implementation of an ESA delta-DOR capability

Paper number

IAC-06-B3.1.06

Author

Mr. Nick James, BAE Systems, United Kingdom

Coauthor

Mr. Ricard Abello, European Space Agency/ESOC, Germany

Coauthor

Mr. Marco Lanucara, European Space Agency/ESOC, Germany

Coauthor

Mr. Mattia Mercolino, European Space Agency/ESOC, Germany

Coauthor

Dr. Roberto Maddè, European Space Agency/ESOC, Germany

Year

2006

Abstract

This paper will describe the implementation of a delta-DOR (delta-Differential One-way Ranging) system within the ESA Deep Space ground station network. The basic delta-DOR technique was originally developed by JPL and it provides very accurate sky-plane measurements of spacecraft position which complement existing line-of-sight ranging and Doppler measurements. The paper will discuss how this technique has been adapted and implemented at ESA ground stations using existing equipment and infrastructure.  Novel aspects of the European implementation of the delta-DOR system will be highlighted.

The ESA delta-DOR system relies on simultaneous open-loop reception of a spacecraft's downlink at the Cebreros, Spain and New Norcia, Western Australia ground stations. The paper will describe the new IF capture capabilities that were added to the existing digital ground station receivers to enable them to act as delta-DOR receivers. These new capabilities were added by writing new software modules for the standard ESA digital receiver (the Intermediate Frequency Modem System - IFMS). With these upgrades the receiver has the ability to record accurately timetagged signals from up to eight IF subchannels. These subchannels can have bandwidths of 50kHz to 2MHz  with a sample quantization of 1 to 16 bits per component. The IF samples are stored locally for subsequent retrieval over a WAN by the correlator facility at ESOC (note that the correlator will be the subject of a separate paper).

We will also present the results of various measurements performed to validate the new system. These results show that the overall performance of the stations, digital receivers and the correlator is very good.

The provision of an independent delta-DOR facility is a significant addition to ESA's spacecraft navigation capability and it has already provided important inputs to the Venus Express mission.

Abstract document

IAC-06-B3.1.06.pdf

Manuscript document

IAC-06-B3.1.06.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.