1. Introduction - Features
Globalsat announced back in March the next generation of BT GPS products, the BT-359 series. This new line offers the power of the SiRF III chipset with a new and attractive design and superb performance. We test the new Globalsat BT-359S alongside its younger brother, the BT-338, under various environmental conditions.
- Globalsat BT-359S
The BT-359 series is the next generation Bluetooth GPS receiver. Globalsat's new top of the line bluetooth GPS is both stylish and functional in true GlobalSat tradition. Taking its design criteria from the market leading BT-338, Globalsat have pushed the limits of GPS even further with greater sensitivity, more accuracy, and longer battery life than ever before.
The GlobalSat BT-359 contains the latest SiRF III Low Power Chipset for high sensitivity. It communicates with Host Platforms (PDA, Laptop, etc.) via Bluetooth Serial Port Profile. With Bluetooth version 2.0 and a built-in ceramic patch antenna, the BT-359 provides faster acquisition times and improves accuracy in urban canyons and under dense foliage. It contains a replaceable battery with a large capacity, which enables the BT-359 to operate for up to 11 hours. A slide battery lid makes it easy to remove and replace the battery without the use of tools. It also supports WAAS and EGNOS for even greater accuracy.
Available in two styles the BT-359S has a solar-look design and the BT-359W has a wave-look design.
- Features
• 
SiRF Star III high performance and low power consumption chipset
• Communications with Host platform Via Bluetooth Serial Port Profile
• Bluetooth Version 2.0.
• Built-in ceramic patch antenna.
• High sensitivity GPS receiver provides faster acquisition times and improves accuracy in urban canyons and under dense foliage.
• Battery life up to 11 hours of operation time, in continuous mode.
• Features power saving mode (powers down after 10 minutes of inactivity).
• Supports WAAS and EGNOS Satellite-Based Augmentation Systems for more accurate corrected position reports.
• Physical dimensions: 82.0 mm x 41.0 mm x 13.4 mm.
- Used chipset
The SiRF III chipset has the following specifications:
Chipset: |
SiRF Star III WAAS enabled |
Frequency: |
1, 1575.42 MHz |
C/A code: |
1.023 MHz chip rate |
Channels: |
20 channel all-in-view tracking |
Sensitivity |
Acquisition: -148dBm
Tracking: -159 dBm |
Position Accuracy: |
10 meters, 2D RMS |
~ 5 meters, 3D RMS WAAS |
Velocity: |
0.1 m/s |
Time: |
us synchronized to GPS time |
Default: |
WGS-84 Acquisition Time (Open sky, stationary) |
Reacquisition: |
0.1 sec., average |
Hot start: |
1 sec., average |
Warm start: |
38 sec., average |
Cold start: |
42 sec., average |
Altitude: |
18,000 meters (60,000 feet) max. |
Velocity: |
515 meters/second (1000 knots) max. |
Acceleration: |
Less than 4g |
Jerk: |
20 m/sec |
Protocol messages: |
NMEA-0183 output protocol, Bluetooth Interface Baud Rate 4800bps |
Output format: |
GGA(1sec), GSA(5sec), GSV(5sec), RMC(1sec) |
Operating temperature: |
-20° to 60° C |
Humidity: |
5% to 95% Non-condensing |
Looking at the SiRF III specs, we notice that the chipset is capable of receiving up to 20 satellites (actually 12 maximum), has very low Hot/Warm/Cold start times and its accuracy reaches ~5m when WAAS mode is enabled.
The main differences between the BT-338 and BT-359S are:
- Different external design (BT-359S is much slimmer)
- BT-359S uses BT v2.0 vs BT v1.1 of BT-338
- 11 hours operation time vs 16 hours (BT-338)
- USB vs AC/DC charger interface
2. The Package
For our testing purposes, Globalsat sent us the retail package that includes:
- the BT-359 GPS receiver itself
- a mini USB cable (for charging via USB interface)
- a cigarette lighter adaptor with USB interface
- and finally a CD-ROM with corresponding software and user's Manual
The current price for the product has not yet been announced, and it will be a while yet until the product hits the store shelves.
The BT-359S is significantly smaller than the BT-338 and much more eye catching:
The battery can be accessed easily by removing the plastic back plate. It is rated at 3.7V with 1300mAh capacity:
The only available jack is the USB power port, located at the right of the device.
Under the battery, we find a label with various information such as the device S/N, certifications, handling instructions. Note our device's #SN, 1 ;-)
The external dimensions are 82.0 mm x 41.0 mm x 13.4 mm with a weight of <70gr, making it truly portable. On the front, there are three LEDs showing the status of the GPS, Bluetooth and Battery.
3. Installation - Tests
The installation of the device is very easy. After charging for about 2 hours or more, you can install it either on your PDA or BT enabled laptop. Remember, the pair key is four zeros (0000), in case the application asks for it. We recorded all produced data for a pre-selected route with
VisualGPSX and later analyzed it with
GPSLog.
In order to measure the TTFF tests ("Time to First Fix" which is the time it takes for a GPS to determine its current position), we used GPSInfo "Cold Start" function.
All tests ran simultaneously, under the same environmental conditions.
Using GPSInfo, we could see among other things, the device's firmware revision (3.1.1.)
- Tests Day One
On the first day, we tested the device with a clear sky, daylight, 39° C.
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Average Signal Level (in dB)
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The BT-359S is powered by the SiRF III chipset, so its performance was very good and came very close to what the BT-338 delivered. Globalsat has notified us that the product may need further fine tuning so there may well be improvements before its final release. But with such good performance already, most users won't even notice the difference.
- Indoor Sensitivity
We placed both receivers inside a house close to a big window and monitored their performance. Both the BT-359S and BT-338 had a 3D fix, but the BT-338 had somewhat higher reception levels.
- Overall impressions
In our tests, the BT-338 seemed to have better reception and sensitivity than the BT-359S, which seems logical since the device we had was an early release. We expect that the final product to hit the market will have been fined tuned and will offer the same, if not better performance than the BT-338.
4. Conclusions
Globalsat's BT-359S is the next generation design for BT GPS products. The new design from Globalsat is very good and very appealing visually. The device we tested was lighter than the BT-338.
In its performance and in comparison to the BT-338, the BT-359S was not that far behind, remembering that both are powered by the famous SiRF III chip. There are some differences as our tests showed, with the most obvious being the higher TTFF times. However, we believe that this and other areas will be improved before the device becomes available.
Overall, we were satisfied with Globalsat's BT-359S and its new design. The retail price is not yet known but should be at around the same range as the BT-338. With the fine tuning that has been promised, the BT-359S could soon become the next champion of the BT GPS arena.
The Positive
- SiRF III chipset offers very good performance
- Supports BT v2.0
- Very small dimensions and low weight
- Attractive design
- Good retail package
- Car charger is included
- Supports WAAS/Egnos
- Include mini-USB port for charging it
- Device turns off after 10mins of inactivity
The Negative
- Doesn't support any automatic power on mode
- High TTFF times
- Cannot connect external antenna (has built-in ceramic patch antenna though)