
It is planned to operate all legal digital modes, including via satellites. Thus, this operation will provide contacts for many amateurs primarily interested in developing and field-testing their equipment and software, as well as those interested in collecting DX contacts for certificates. Salas y Gómez will provide a new island for the Islands-on-the-Air (IOTA) program, administered by G3KMA for the Radio Society of Great Britain.
The expedition team will establish a base camp on Easter Island from which the scientific and radio operations will be conducted. This team will concentrate on providing contacts with amateurs on digital modes, and will provide the link to the team at Salas y Gómez. The Salas y Gómez team will establish 2 stations for about a week. The Easter Island stations will use the callsign XRØY, and the Salas y Gómez stations will use the callsign XRØZ.
A central goal for this project is to implement a variety of innovations that have not previously been used for radio DXpeditions. The following items have been implemented for the 1995 EI/SyG expedition.
The greatest effect of this project, however, will be to help change the DXpedition from a performance/spectator event to a participatory event, and to increase the efficiency and enjoyment of the sport for as many persons as possible.
The TCS/AC is designed as follows: We desire to carry out communication across a link between a remote station R and a set of local stations L. This link is very poor quality, perhaps due to weak signals, interference, unknown schedules, unknown transmission and reception frequencies, etc. Furthermore, the RL link is in place for only a limited period of time. At the low rates of communication over this link, it is unlikely that a successful exchange will be made before the link is broken, or that the link cannot be established in time. Although it is possible to improve the quality of the RL link by adjusting it operating parameters (e.g., selecting transmit/receive speeds, frequencies, etc.), it is not possible to pass enough information over the link to effect this improvement before the link is broken.
The TCS/AC strategy is to establish an auxiliary channel AC which is of very high quality but which has very limited capacity. The auxiliary channel carries information that can improve the operation of the RL link, but it cannot carry the communications itself. Thus, the auxiliary channel will assist in improving the RL link, but that is all.
We apply this to the typical problem faced by an amateur radio expedition ("DXpedition") as follows: A DXpedition involves communications between a single remote site (typically an island) and many individual local sites (amateur radio stations). The goal is to make a confirmed contact with each station, by which is meant two-way communication between the remote and local sites. The problem is that propagation of radio waves through the ionosphere between the two sites is noisy, subject to interference, and occurs for only a few hours each day. Typically there is no capacity to test the propagation paths and optimize the operation of the stations, e.g., by selecting frequencies, mode, and data rates. Often, the greatest challenge is just finding the correct frequency on which to listen or transmit, and being on frequency at the right time.
In operation, the island station sends data through the AC, providing the local amateur stations with information about the operations and guidance for adjusting their operations. The local stations in turn feed information on quality of their contact back through the AC to the island station, which adjusts its operations accordingly. Thus, the contacts made directly between the island and the amateur stations are enhanced by means of the auxiliary channel.