Scritto da gbo | 13 Maggio 2006
Posted in English Contents - English Contents

SoloPalmari GPS Test Drive (Part I)

Comparison of 6 PDAs and GPS

This is the report of a one-day travel. We had two objectives in mind: to test the accuracy of several systems with PDA-GPS components, and to reach Ariccia, a nice town close to Rome, in the area of the Roman Castles.
.
ZioMeme, the youngest of the group, is at last available to disclose the name of his favourite "fraschetta", a typical Italian restaurant quite common in the area: he states we'll get the best food in our life. Guido, the oldest, would prefer to use a restaurant guide. Roberto, laughing, is convinced that we'll complain anyway at the end of the day. Myself, I just want to test the PDAs and to get some food, no matter in which restaurant.

- The tools

The track we have chosen consists also of road in the countryside: the first requisite of having a vehicle capable of travelling in those roads is satisfied by the car above.
For our tests we have used 6 different PDAs, ready for a very tough competition. Here they are, strictly in alphabetic order: Fujitsu Siemens C550, the "multimedia PDA" (review), coupled with the GPS receiver Globalsat BT-338; N520, the entry level of FSC convergent devices (review); N560, currently the top of the Japanese-German vendor (review); HP hw6515, the first PDA-phone with AGPS; MIO A201, the budget model of the series; MIO A701, the PDA phone including a SiRFinstantFix system (review)

These devices are not the only electronic companions of our tests. We also have some newcomers, but we are not going to publish the results for them, due to obvious reasons. An example is the T830 by Fujitsu Siemens (English review), still in a preliminary phase, that is expected to be available on the market by next July/September. The firmware it implements is at a too early stage to ensure an active participation to the tests and to guarantee reliable results. Side by side to this UMTS PDA phone we have included other devices: JasJar, the "king" (review); Globalsat GH-601, the wrist receiver; SD-502, the Secure Digital with a GPS antenna inside; some Nokia smartphones, and a long list of Bluetooth GPS receivers of old and new generation.

- Start and first phase
Finished with the presentations, checked our devices, planned our tour from the heart of Rome to a restaurant in the countryside (hoping that Zio is not wrong ), our trip can start. First step, "Appia Antica". Let's go.

We are in the archeological area of the Roman, just for a quick test of Globalsat GH-601, a receiver to use for outdoor activities, like geocaching, a sport of increasing importance for those who love both nature and technology.


{mospagebreak heading=- Setup and start &title=- Track log number 1}

SoloPalmari GPS Test Drive (Part II)

Comparison of 6 PDAs and GPS

- Again on the road
Let's drive back on a normal road. The landscapes you can see in this area, especially at sunset, when the sun paints the sky in red, have delayed our planned tour.

The main phase of the test, for which we shall prepare a detailed report, will take place in Ariccia. It's here that the recording of "track log" will be really meaningful, because GPS receivers will be used in mixed tracks, consisting of urban and outdoor parts, in large road and small streets.

- Purpose
The purpose of the three tests is to verify if the driving route corresponds to the track logged by PDA-GPS: the more the tracks overlap, the more the antenna is precise.

-Tools
They are all free and easy to use. The tools we have adopted allow drawing a map containing a graphical representation of tracks. They can be used also by non professional users, in case you are interested in repeating directly our experience in other situations.
Let's see briefly the main features of the tools.

• - VisualGPSce: it's a software, compatible with all the most recent operating system Windows Mobile, that saves in a text file all the information provided by a GPS receiver on a track: latitude, longitude, altitude etc.  The "track log" can be further reproduced in a lab to identify all movements, as they have been received by the GPS (not necessarily they will correspond in full to the real track log). VisualGPSce has been installed on all the six devices used in this test.
  

• - Google Maps: it is a service provided by the company that has developed the famous Internet search engine. It consists of a detailed cartography, that can be viewed on a web page. It can be used to determine addresses, points of interest and make routing operations.
  

• - GPSVisualizer.net: this web site allows the uploading of track logs, that can then be reproduced in a graphical way with lines that represent the tracks. These can be overlapped to Google Maps, so that we can compare the tracks ad seen by the GPS receiver with the realist cartographic one.

- Instructions for the use of the map
The map shown below represent the track driven during the test by the team of SoloPalmari. It starts before Ariccia, a small city close to Rome, and it ends in the centre of the town itself. The map is totally interactive, thanks to Google's technology. Here is a list of the main functions. We advice you to read carefully these instructions to test all the features, in some cases even unexpected.

1. - Zoom: the vertical bar on the left allows to increase or decrease the zoom details. With a lower detail you have a larger view on the whole track; the higher zoom level allows to view with more details the track recorded by VisualGPSce for every PDA. Attention: the higher zoom can only be used in "G. Map":mode; satellite images are not allowed to present data with great detail, due to privacy reasons.
2. - D-Pad: as with the buttons of a PDA, the group of buttons in top left position allows to move along the map in directions North-South-East-West. By pressing the star key you can go back to the initial position.
3. - Panning: to move inside the map or move to portions of the map currently not visible, you can use the mouse pointer: just click on the map, keep the mouse button pressed and move the pointer in the direction you want.
4. - Menu: it contains three elements, that allow you o select the image background. The options are "G. Map" (Google Map), which includes roads, streets, crossings, the name of some streets and of some location (like in a normal map); "G. Satellite" (Google Satellite) provides the view from a satellite image; "G. Hybrid" (Google Hybrid) is an intermediate format, that can associate both layers.
5. Legend: represents, in different colours, the track of each device. With a click on the title of the track you can select or deselect it. This function is useful in those cases in which, due to the high level of zoom, track overlap, and cannot be distinguished separately.

- Track log number 1: Mio A701, Mio A201, HP hw6515




In this first test we have compared three devices with integrated GPS: Mio A701 (red), Mio A201 (green), HP hw6515 (blue). The tracks are very regular, overlapping with the real one, for the first two devices. This is not true for the Pda-phone from HP: its track is always far away from the real route. The situation is even worse when, entering the village through an underway, receiving the satellite signal is really very difficult: in this situation the HP model gets lost. As justification for this, we must say that the HP hw6515 is the only one not to implement the efficient SiRF Star III, but rather an AGPS Global Locate receiver.

{mospagebreak title=- Stops during tests}

SoloPalmari GPS Test Drive (Part III)

Comparison of 6 PDAs and GPS

- Stops during tests
Although we wanted to collect as much data as possible, we had to stop from time to time. The car has only two power plugs in the front side: we had to switch them frequently, in order to power the various units. Furthermore, we had to stop track logging from time to time, to avoid an increase in size of logs, that would then become too large to be easily redrawn by the mapping system: the track would be come too long to be easily identifiable on a web page.

ZioMeme is very active, and his tapping ability, as well as he selection of right power cable for each device, overcomes the rest of the group. He is able to activate simultaneously track logging on three devices.
We can see at a glance a few parameters on the behaviour of each system in "First Fix", which is the time needed by the receivers to first identify the position of satellites. The most performing is undoubtly Mio A701, whose "First Time To Fix" is even lower than 10 secondi (without using the SiRFinstantFix function - check why), followed by A201 and C550  (with the Globalsat BT-338 receiver) with less than 50 seconds. At the end of the group are the HP PDA phone and the two Fujitsu Siemens N520 and N560, that present an irregular behaviour, depending on the visibility of satellites: in some situations it takes 60 seconds to get the first fix; in some other cases it took 3-4 minutes.

Pictures are taken during driving or a stops: in these cases one of us remains in the car to take pictures, while the rest of the group walk around and have a look at sunset.

We were at sunset, and now it's dark. It's getting late: we have time for a final checking of PDAs and a quick look to check that all programs are working correctly. We start again.

{mospagebreak title=- Track log number 2}

SoloPalmari GPS Test Drive (Part IV)

Comparison of 6 PDAs and GPS

- We can't get lost
Travelling at night, with all the light coming from the displays of the PDAs, is not an easy task. We drive carefully, particularly when we turn left or right to test the performance of the GPS receivers. On the other hand, we know we can't get lost: in the car we have 10 GPS systems (the 6 ones in test and 4 other devices for ... backup).

Those who don't drive have anyway plenty of things to do: we must take care of data logs, speed, altitude, to get an idea of the behaviour of the different systems.

- Track log number 2: FSC N560, N520, C550 (with BT-338)




In this second test, track logs collected by VisualGPSce are used to compare three Fujitsu Siemens models: N560, N520, C550. The  C550 does not include a GPS receiver: it has been coupled with a Bluetooth Globalsat BT-338 antenna, implementing the chipset SiRF Star III (as in the two other systems).
The behaviour of the three models has been uniform, and only in some situations the Bluetooth receiver is better linked to the route. We have to admit, however, that we positioned the Globalsat receiver in the car in a position where it could see a larger portion of the sky.

{mospagebreak title=- Track log number 3}

SoloPalmari GPS Test Drive (Part V)

Comparison of 6 PDAs and GPS

- The final route
One more stop. We are about to start our last test, inside Ariccia.

Let's briefly summarize the various systems: in the top left position the Globalsat GH-601 (the hair in the driving mirror are mine); immediately below Fujitsu Siemens T830 and HP hw6515. At the right, MIO A701, MIO A201, FSC N520 and N560 (this last has been inserted in a car support with amplification of the voice that provides driving directions and a power plug). The FSC C550 was in the hands of Roberto (no more room available in the front of the car...).

- Track log number 3: Mio A701, Mio A201, HP hw6915, FSC N560, N520, C550




In this last test we compare the tracks of all the systems. Since there is a large number of coloured lines, we suggest to select a high zoom level. Even better if you temporarily deselect some of the logs. We remid you that you just have to click on the titles in the legend to switch on and of a certain track.

{mospagebreak title=- Conclusions and dinner}

SoloPalmari GPS Test Drive (Part VI)

Comparison of 6 PDAs and GPS

- Ariccia!
At last we get at the conclusion of our test. We reach the area of "fraschette", traditional and cheap local restaurants, where you can get typical food and good wine.

After hours and hours of test, we have very clear in mind which is the best PDA (for GPS use) among those that we have examined. Here is the situation, as defined while eating and discussing, in a table covered with ham, cheese, bread, local food and with glasses filled with red wine.

1. First place: Mio A701. Its Time To First Fixing is very fast in every situation, and its chipset keeps the position of an incredible number of satellites even in the most critical situations.
2. Second place: Mio A201.Similarly with is youngest brother, it has a very efficient GPS system. A plus is given by its display, with excellent contrast and readability even in conditions of sunlight (a feature that is also present in the A701).
3. Third place: FSC C550 with Globalsat BT-338. The receiver is up to its fame, it is one of the best GPS antennas available on the market. Concerning the display, the C550 provides the best in dusk or darkness, where the VGA touchscreen looks like a high resolution picture.
4. Fourth place ex aequo: N520 and N560. Tracks follow closely the real route, but the time to get the first fix could be improved. We believe that the engineers at Fujitsu Siemens could work on the firmware of both PDAs to improve the algorithm used in managing GPS data.
5. Fifth place: HP hw6515. Its performance has been disappointing. In open areas, with no obstacles in receiving satellites, no problem. But if it misses the sky and satellites for a few seconds, it restarts the slow process of acquisition. We hope this has been improved in the HP hw6915.

- "Faciòli con le cotiche"
ZioMeme was definitely right: cheese, excellent salame, ham and porchetta (a local specialty).

Wine too was not too bad: sparkling, delicate, perfect with "fagioli e cotiche" as well as with sweet "ciambelline" and for the final toast. The bill has been paid by Guido: he is not used to wine and was getting asleep...

At the end, we have kept a small game: what is hidden behind the digital cover? We can provide you a clue: it is a very advanced device, but we were not allowed to show it to you in the middle of wine glasses, "salamini", "cotiche" and "faciòli". At least until it won't be officially disclosed to the public. However in these pages we have left some evident clues: it won't be a problem finding it.

As for the "fraschetta", no hope. We shall never reveal for no reasons, its name. ZioMeme has given us the name of his "fraschetta" as a secret, and he has our word. Can't say it to nobody! However, if someone wants to invite us for dinner and  pay the bill, well: he doesn't need our words, when we will be there it's enough to read the sign of the restaurant...

We thank Microchip that made available some of the supports used in the test, as well as Globalsat for the GPS receivers.

< Prec.		Succ. >