Attention Newbies! Everything (almost) you want to know about GPS (Part 1) - Page 2

Ladzio · 05-24-2005, 06:13 PM

Good info about GPS software for those with older PDAs or Palms:

http://www.gpsinformation.org/dale/P...otgps.htm#soft

Harlanc03 · 05-24-2005, 06:38 PM

Are there any free GPS Navigation software progs?

Bugbyte · 05-25-2005, 11:20 AM

All the various specs confuse me. WAAS and EGNOS and Sirf and xtrac and DGPS - I don't know what any of that stuff means or how it should affect my choice. 10-15-20 meters seems to be a standard accuracy. Is that really about as good as it gets? I had always thought GPS could get as close as just a couple of meters.

DGPS

DGPS stands for "Differential GPS" and refers to a method of referencing various ground station broadcasts to improve the accuracy of GPS signals. At one time, the commercially available GPS signal was "degraded" by the US military to reduce its accuracy to 5-10 meters. DGPS was a method to correct for that degradation. The degradation was turned of some years ago. DGPS operates similar to WAAS, below.

WAAS

WAAS stands for "Wide Area Augmentation System". A detailed explanation of WAAS can be found here: http://en.wikipedia.org/wiki/WAAS. The short version is that WAAS is a system of GROUND based GPS transmitters operated by the FAA that are intended to increase the accuracy of the GPS signal. It's primary purpose is to allow aircraft in a metropolitan area that are equipped with WAAS receivers to fly more accurate instrument approaches at airports with the proper WAAS approach procedures. WAAS provides 1-2 meter accuracy horizontally and 2-3 meter accuracy vertically.

LAAS

LAAS stands for "Local Area Augmentation System". Same idea as WAAS but installed at each airport. LAAS is even more accurate than WAAS and allows approaches to be flown in very bad weather conditions.

You don't need WAAS or LAAS. First, WAAS is expensive and unlikely to be installed anywhere but the major metropolitan areas. The FAA has no money and won't deploy it very quickly. By then, you'll own another receiver. Also, consider how accurate you really need to be. So what if you are 30 feet off on the map? First, how can you be sure the error comes from your GPS or perhaps because the map you are using is inaccurate? Second, even if you're 30 feet off, there are very few instances where this will get you lost.

Your best bet for accuracy is to receive as many satellites as possible. The more satellites, the better. Most members here report receiving 6 or more, but that can vary depending on time of day and weather conditions.

EGNOS

EGNOS stands for European Geostationary Navigation Overlay System. EGNOS supplements GPS, but probably only in Europe to begin with. It is similar to WAAS in it's functionality, adding accuracy to the signal (2 meters) and uses a combination of ground and geostationary satellites to achieve this. EGNOS is a precursor the the Gallileo positioning system, a European satellite based positioning system. EGNOS becomes operational in June 2005.

SiRF

SiRF refers to a chipset used in GPS receivers, much like Intel Pentium refers to a type of processor. SiRF chipsets are supposed be be pretty good (anyone with comments here?). An excellent explanation of the various SiRF chipsets is here: http://www.pocketgps.co.uk/xtracornoxtrac.php

SiRFXTrac

XTrac is a software firmware enhancement used in a variation of the SiRF chipset that provides increased performance over regular GPS units. It's main purpose is to tune in stronger satellites first, then work on aquiring weaker satellites that might be rejected by other GPS receivers. Bottom line - it makes your GPS more sensitive. It might make the time to first fix a bit slower, however.

mattress · 05-25-2005, 05:31 PM

sticky this!

Marvin Hlavac · 05-25-2005, 07:37 PM

Yes, and even if we used more accurate GPS systems it would in my humble opinion not help us in any way in our cars and trucks. I'm not the greatest at math, but let's try to look at it this way. If we travel at a moderate speed of 60 km/h (~40 miles per hour) in one second we will pass approximately 17 meters (~51 feet). GPS receivers refresh our GPS position once every second.

I'm guessing that most GPS receivers give us about 10 meter (30 feet) accuracy. How could it possibly benefit a driver to have a GPS receiver with accuracy better than 10 meters if just in one second we pass distance much greater than 10 meters?

Bugbyte · 05-25-2005, 09:51 PM

Quote: Originally Posted by Marvin Hlavac

Yes, and even if we used more accurate GPS systems it would in my humble opinion not help us in any way in our cars and trucks. I'm not the greatest at math, but let's try to look at it this way. If we travel at a moderate speed of 60 km/h (~40 miles per hour) in one second we will pass approximately 17 meters (~51 feet). GPS receivers refresh our GPS position once every second.

I'm guessing that most GPS receivers give us about 10 meter (30 feet) accuracy. How could it possibly benefit a driver to have a GPS receiver with accuracy better than that if just in one second we pass distance much greater than that?

Makes sense to me. You just need to be in the ballpark, not down to the foot.

aoLhaTer · 05-26-2005, 02:09 AM

I think it should be noted in the software list that MapPoint and Streets and Trips are identical, MapPoint just has a few more features

Bugbyte · 05-26-2005, 11:50 AM

Updated.

Question · 05-26-2005, 12:22 PM

Can I play tron using gps?

Yes.

Cocoman · 05-26-2005, 01:10 PM

Another really great GPS solution is the Garmin GPS 18 and City Select USA(has Canada maps too)

Not to sound like a spammer but you can purchase the receiver, software and maps for north america(USA and Canada) in one package that only costs $114US(or $150CAN) from GPSCITY:
Canadian Buyers: Garmin GPS 18 USB
US Buyers: Garmin GPS 18 USB

Here are some of the Specs:

Choose between USB or Serial Interface(links above are for USB version)
Includes maps for USA & Canada(maps for europe also available)
extremely small receiver with magnetic base
mapping software has daytime and nighttime skins which automatically toggles between the two
Has 5 million points of interest(for North America)
Map and POI updates available yearly
Very low resource footprint
Voice prompting for turn by turn directions

Shipping is cheap($5CAN with canada post) and FAST. I ordered mine
mine from gpscity.ca and it arrived 2 days later.

Creating a front end was not too difficult either and i now use that for the GPS system in my car. Its kept inbetween the glove box and dashboard and I still get good reception in most areas.

The software performs very well and uses VERY little memory. Also, I noticed that some people had problems planning coast to coast trips with software like Destinator. Just for fun, I planned a trip from Victoria, BC Canada which is on an Island, to Los Angelos, California. It took a short while to calculate it(understandable) but the program came up with a feasible solution which even showed me which ferry to take.

Oh and lastly, the voice prompts, as nice as they already are, can be customised. They are simply wave files so they can be replaced with any voice or sound you like and don't suffer as much from the "Steven Hawking effect" (no offence intended to Dr.Hawking). Anybody out there with a sexy woman's voice

Some screenshots are available on my project thread and eventually i'll post a video showing the GPS in action:
2005 Mazda 3 Install

Bugbyte · 05-26-2005, 04:03 PM

I've never heard of City Select! Does it only come with the Garmin? I did a quick Google and it appears to only come as a bundle.

Cocoman · 05-26-2005, 06:44 PM

The Garmin unit I ordered came with :
1) MapSource CitySelect North America
- Provides maps, POI
2)nRoute
-used for viewing the maps, creating routes, searching for POI, waypoints, etc
3)The GPS receiver

I "believe" you can download nroute for free but you need to purchase the maps from garmin. I'm not sure if the download link on their site is an update or the full version. Regardless, you may be able to use it with non-garmin hardware, but im not sure.

Even if you decided to use non-garmin hardware, it may not be to your benefit because City Select North America is about the same price as the Garmin GPS 18 deluxe(which includes city select north america and nroute AND the receiver)

Marvin Hlavac · 05-27-2005, 07:28 AM

Quote: Originally Posted by Cocoman

...you may be able to use it with non-Garmin hardware, but I’m not sure.

I'm not 100% sure either, but my guess would be that no, you cannot use nRoute with a non-Garmin GPS receiver. That software will likely be not compatible with a "regular" GPS unit that outputs the standard NMEA sentences. But don't quote me on that, because I have never tried the above mentioned software.

Marvin Hlavac · 05-29-2005, 03:27 PM

Quote: Originally Posted by Bugbyte

Microsoft Streets and Trips

Cons - NOT TS friendly, small text, no turn by turn voice guided directions, no 3d view, trouble integrating it into CF, no OSK. Requires you to manually start the GPS tracking each time the program is launched. No way to change bright map colors, making it wash out in sun.

I agree with all of the above, so there is no need to edit it ;-) I just have a couple of additional pieces of information to consider.

1. Since the release of the 2005 version, which introduced improved GPS functionality, the most requested feature appears to be the turn by turn voice prompts, so chances are good Microsoft has listened to the masses and the upcoming 2006 version may bring us a pleasant surprise.

2. S&T 05 does not have night color theme, but there are a couple of less known ways to help this a bit. View one picture >>here<<

3. Perhaps S&T could be made more touch screen friendly and more usable to carputer community by modifications by ResHacker. Dumpper, a member of gpspassion.com has discovered how. In the past I opened the EXE file and there was almost nothing that I could do, but Dumpper today found we have to ignore the EXE and we have to go somewhere else... Read more >>here<<

Telos · 05-31-2005, 07:15 AM

Great stuff guys. I've been searching in this forum for preferred online dealers of GPS units. Anyone have an online dealer that they have had a good experience with? This might be good information to add to this guide.