GNSS Markets and Applications - Understanding GPS: Principles and Applications - page 658

The military users desire many of the same system attributes but are more con-
cerned about improving the jamming resistance. While unlikely that they will be a
regular user of GALILEO, they understand its potential for military applications, as
many countries have done with the GPS C/A code. The military also wants shorter
TTFFs and direct signal acquisition without any reliance on civil signals.
With these user desires in mind, user equipment manufacturers have addressed
various segments of the market with products that are useful to the customers and
profitable to the companies involved. From the low-powered receiver chip or chipset
to complete stand-alone receivers, there is a product to fit all end users of the GNSS.
Some of the manufacturers offer both chipsets for others to incorporate into prod-
ucts and complete GNSS receivers for sale directly to end users. Some sample prod-
ucts are shown in Figure 12.6.
Note that most of these products have the ability to receive both GPS and
WAAS signals so they are truly GNSS receivers. Future models will include
GALILEO capability as well. NovAtel has already begun a GALILEO proof-of-
concept receiver development program under contract to the Canadian Space
Agency (see Figure 12.7).
Each market segment has unique requirements over and above various environ-
mental requirements and emission and safety standards set by regulatory bodies
such as the FCC and Underwriters Laboratory. GNSS chipsets for incorporation
into cell phones or PDAs must be very low power, low cost, and small. They also
must be able to make use of assisted-GPS signals delivered to them over the cellular
network itself. Handheld receivers must also have low power and low cost. Receiv-
ers that are part of car navigation systems operate off vehicle power, so they can
draw more current than the handheld units. However, these receivers are usually
Collins military handheld
SiRF chipset
Magellan handheld
Trimble surveyor
Pioneer car navigator
Figure 12.6 Chipset, handheld, car navigator, and GPS surveyor. (Courtesy of Magellan, Pioneer,
Rockwell-Collins, SiRF, and Trimble.)