It was not only GNSS receiver producers, primarily focused on the land-survey market, who were interested in participating in this Product Survey, but also manufacturers of OEMs and producers of high-precision navigation systems.

OEM stands for original equipment manufacturer, but the term is simultaneously used to indicate products used by a second company as (core) component in the goods they bring to market. In contrast to the last survey, published in October 2007, we have skipped listing OEMs this time. Not being complete instruments suitable for direct use in the terrain, they are of primary interest to manufacturers who use them as components in their specialised products, and are of less importance to the land surveyor, the end-user at whom this survey is targeted.

One manufacturer making use of OEMs is Forsberg Services, producer of high-precision navigation systems. The lower sections of its columns primarily list N/As (Not Applicable) because the company does not supply off-the-shelf GNSS systems for land survey application, but rugged positioning systems for use on moving platforms which have to operate in harsh environments. It also provides customised solutions and components for building an own system. Integration of Novatel OEMs with other hardware and software components serves a primary market in aircraft navigation, military applications and machine guidance. Navcom products are also aimed at high-precision navigation applications using the in-house development Global Satellite-based augmentation system Starfire Network. The Navcom SF-2110 will be brought to market this autumn.

For a country able to organise the Olympic Games as well as a successful 21^st ISPRS Congress in Beijing, China produces remarkably little survey equipment. Only HuaCe China HuaCe (CHC), based in Shanghai, provided a contribution. We welcome ALTUS Positioning Systems Inc, based in southern California, USA, which recently introduced the APS-3 system, the core of which consists of Septentrio's dual-frequency GPS/Glonass OEM receiver module AsteRx2. Septentrio also produces the PolaRx3 system, which enables dedicated high-precision measurements and has been specially developed for use in GPS reference stations. In addition to the PolaRx3 listed here, Septentrio manufactures the PolaRx3G, with slightly different specifications.

Henk Key, contributing editor, and Mathias Lemmens, senior editor, email: henk.key@geomares.nl