WAAS in AUS?

Kerry · Post by **Kerry** » 28 August 05 9:14 pm

Magellan 3000XL was 8seconds behind the Explorist, which i'd say is a big deal considering a GPS computes its position entirely based on time.

8 seconds? No big deal it's a totally different "time"

Zytheran · Post by **Zytheran** » 28 August 05 9:22 pm

Hmmm, just powered up the GPS and as per usual it shows the numers of the last birds tracked (Garmin Legend) before it finds some new ones. I had 2 birds with ID's in the thirties showing..
Something is definately going on ..

energizer61 · Post by **energizer61** » 28 August 05 9:41 pm

Yep, same here.... it's got me interested, I'm wondering if the MSAS system has been turned on, according to this site http://www.shef.ac.uk/~ap1gjb/researchoverview.html
It is supposed to be turned on by 2005

Other governments are developing satellite-based differential systems similar to WAAS. In Europe the Euro Geostationary Navigation Overlay Service (EGNOS) is being developed while in Asia it's the Japanese Multi-Functional Satellite Augmentation System (MSAS). Both systems are scheduled for full operation in 2005. Eventually, GPS users around the world will have access to precise position data using these and other compatible systems.

and

MTSAT Satellite-Based Augmentation System (MSAS)

The MTSAT Satellite-Based Augmentation System (MSAS) is the wide-area augmentation system being developed by the Japan Civil Aviation Bureau (JCAB) for civil aviation. This space-based augmentation system will provide en-route through precision approach navigation services for all aircraft within Japan airspace.

The MSAS employs a ranging function to generate GPS-like signals and enable aircraft to use the Multi-functional Transport Satellite (MTSAT) as an additional GPS satellite. The MSAS is similar in function to the WAAS/EGNOS and generates correction data for GPS and GLONASS. The system shall be fully operational in 2005 after.

The system consists of Ground Monitor Stations (GMS), Monitor and Ranging Stations (MRS), Master Control Stations (MCS) and Navigation Earth Stations (NES). The GMS collect range measurements and send them to the MCS which monitor and control the system, calculates MTSAT orbit, ionospheric delay, and correction data, determine system integrity, collect range data and send the information to NES for uplink. The MRS receive the GPS/GLONASS/MTSAT signals and collect range data.

There are also monitoring stations in Hawaii and Australia to increase the service area beyond the Japanese borders.

Kerry · Post by **Kerry** » 28 August 05 9:49 pm

If you have a legend with firmware 3.2 or less it did have the ability to do things it shouldn't have been doing. Since Firmware 3.40 one of the updates was to

Improved WAAS/EGNOS satellite selection algorithm to select the satellite with the most beneficial corrections given the unit's current position. A unit will not use a WAAS/EGNOS satellite if the unit's current position is outside of a given WAAS/EGNOS satellite's service volume.

Basically too many users were thinking they were getting WAAS in areas where it was totally ineffective. WAAS reception was a bit of a con job before controls like this were put into place.

A unit will not use a WAAS/EGNOS satellite if the unit's current position is outside of a given WAAS/EGNOS satellite's service volume. Australia is NOT a part of WAAS or EGNOS or MTSAT service volume.

Cheers, Kerry.

Kerry · Post by **Kerry** » 28 August 05 10:05 pm

MTSAT-1R was only launched on jan 2005 and way way behind schedule due to some previous mission failures.

Based on the original failed launch in 2003, which would have put MSAS on around a 2005 start up it simply did not happen. Won't see anything out of MSAS until at least 2007 and neither is there any MSAS ground stations in Australia at present. But then 1 ground station is simply not enough to cover the whole country.

Civil Aviation in Aus is going in a totally differnet direction to WADGPS (WAAS/EGNOS/MSAS etc) as these types of systems are simply way to expensive and as WAAS has shown, WAAS has not meet the FAA's original spec with funding now basically on a reduced budget.

Cheers, Kerry.

GIN51E · Post by **GIN51E** » 28 August 05 11:26 pm

Still doesn't explain why all of a sudden we are picking these signals up when we didn't before hand....

its fair enough having a few people saying how its not possible and wouldn't be accurate but can you explain why we have just started to pick up these signals? or you simply don't know?

riblit · Post by **riblit** » 29 August 05 12:32 am

GIN51E wrote:Still doesn't explain why all of a sudden we are picking these signals up when we didn't before hand....

its fair enough having a few people saying how its not possible and wouldn't be accurate but can you explain why we have just started to pick up these signals? or you simply don't know?

If you go back through the posts in this thread the answers are there.

From what has been said:
POR (over the Pacific) is just above the horizion, you were on or near the coast, atmospheric conditions were good enough to facilitate reception.

However WAAS is more than a satellite, it is a couple of satellites carrying the same data and a number of ground stations that provide that data. The ground stations are in North America, the data they provide is good far about 200nm around each station, totally useless for Australia.

The new Garmin receivers are smart enough to know not to use WAAS when they are are outside the area where it works, the Magellan range, apparently not.

Hounddog · Post by **Hounddog** » 29 August 05 2:01 am

Gee!! I have been at work doing an 18 hour shift. Hasn't this thread come along.

I think because of all the fancy lingo and inclusions on the newer GPS units, one can be forgiven for being lost as to what is working and what's not. Suffice to to say that WAAS is NOT operational in Austrtalia and therefore it is of no use to have it enabled on your GPSr. I just bought a new unit myself and even though it is WAAS capable the first thing I did was make sure that the WAAS feature had been disabled....it had.

You are really doing yourself a diservice by leaving it active in Aus. Your unit is only going to spend a whole lot of time searching the sky for a ghost, so turn it off.

Hounddog

Hounddog · Post by **Hounddog** » 29 August 05 2:50 am

POR (over the Pacific) is just above the horizion, you were on or near the coast, atmospheric conditions were good enough to facilitate reception.

I actually read somewhere that POR is about to be taken out of service and replaced with a more powerful bird. In fact the launch was supposed to have already taken place. 

There have been many reports of interference (and therfore inaccuracy) from POR when WAAS is turned on in Australia. That's why I say turn it off. 

If you want to see how close POR is to Aus and get a view of it's footprint click here.

http://www.fourmilab.ch/earthview/satellite.html

Choose "Spacenet 4" from the list.

Hounddog

Deco · Post by **Deco** » 29 August 05 8:19 am

Crew153 and I were out yesterday afternoon and on came the WASS.

Max didn't believe me, so he put new batteries in, enabled WASS and presto "3D Differential" can up on the screen.

I have just driven back from the gold coast this morning and it was "Differential" the way to Brisbane.

Cheers Jason

PS we are both using Garmin 72 units

Biggles Bear · Post by **Biggles Bear** » 29 August 05 8:49 am

We noticed yesterday that the Magellan Platinum was showing WAAS, as mentioned by others this is something that it has not done before, and no we haven't done a frim ware upgrade latley.

Deco · Post by **Deco** » 29 August 05 9:10 am

Birds # 2 and 9 are coming up every time with "D" s on the screen here in Brisbane.

Kerry · Post by **Kerry** » 29 August 05 10:12 am

GIN51E wrote:Still doesn't explain why all of a sudden we are picking these signals up when we didn't before hand....

its fair enough having a few people saying how its not possible and wouldn't be accurate but can you explain why we have just started to pick up these signals? or you simply don't know?

I wouldn't say this is something that has happened all of a sudden as it's been a well known fact (well I thought it was) that POR romped into Australia with a carrier but no corrections and this isn't something that is exactly new, it has been going on for quite a few years.

Initially the signals had the affect of degrading the accuracy, quite considerably in fact and then followed the preventation of these incorrectly used signals by many manufacturers. There needs to be a very clear understanding that simply receiving half the carrier from POR does not make it WAAS, far from it.

Like I said this isn't something exactly new and before some of the manufacturers closed the hole and tightened the correction/locality footprint this is what "WAAS" did to the signal in Australia.

WAAS should simply be disabled on any GPS in Australia, it's simply a waste of rescources attempting to use it and if you think you are receiving WAAS "proper" then I would like to see the data to back that up.

Cheers, Kerry.

riblit · Post by **riblit** » 29 August 05 10:31 am

Well this is easy.
All those who are receiving WAAS corrections please turn your GPSr on, place it on the ground for 30 mins and post the resulting track log.

Kerry · Post by **Kerry** » 29 August 05 10:44 am

Ah! require 24 hour blocks of 1 second data as raw as possible and also an accurate and "absolute" reference position. A 30 minute track log means ziltch.

Cheers, Kerry.