eTrex Series

[yoladu]

Ok my simple review of my etrex Legend HCx, sensitive but not accurate enough.



A clearer and bigger picture in this below link because my picture upload limit is 800pixels

http://img.photobucket.com/albums/v502/ ... llse-1.jpg

There are some flaws to your method in determining the accuracy of the GPS.

First, you cannot use the track log. The dots to the track could be many seconds apart, and when you are using it in an offroad environment, the GPS is unable to lock on the road, so it will drift.

The particular section of the maps you are using could be done few years back so there could be some errors too. So if your track does not plot exactly on the line of the map, do get too worry.

The best way to determine the accuracy of the GPS without the need of all the fancy equipment, is to find a heli-pad. On most heli-pad, especially those in military areas, the GPS coordinate is displayed. So you can compared that with the actual reading of your GPS.

Above all, the garmin GPS are for hobbyists, so its take the accuracy can never be comparable to military GPS using P(Y) code.

[lfy81]

Ok my simple review of my etrex Legend HCx, sensitive but not accurate enough.



A clearer and bigger picture in this below link because my picture upload limit is 800pixels

http://img.photobucket.com/albums/v502/ ... llse-1.jpg

There are some flaws to your method in determining the accuracy of the GPS.

First, you cannot use the track log. The dots to the track could be many seconds apart, and when you are using it in an offroad environment, the GPS is unable to lock on the road, so it will drift.

The particular section of the maps you are using could be done few years back so there could be some errors too. So if your track does not plot exactly on the line of the map, do get too worry.

The best way to determine the accuracy of the GPS without the need of all the fancy equipment, is to find a heli-pad. On most heli-pad, especially those in military areas, the GPS coordinate is displayed. So you can compared that with the actual reading of your GPS.

Above all, the garmin GPS are for hobbyists, so its take the accuracy can never be comparable to military GPS using P(Y) code.

Luckily the group I am with, is experienced with the area, otherwise sure lost. I am just dissapointed with the GPS accuracy, that's all, especially when trekking for an hour like that, and suddenly the accuracy when "OFF" the mark so huge.

And lastly, I forgot the GPS thing is divided for the military as well as civilian use meaning less accuracy for us.

[yoladu]

Luckily the group I am with, is experienced with the area, otherwise sure lost. I am just dissapointed with the GPS accuracy, that's all, especially when trekking for an hour like that, and suddenly the accuracy when "OFF" the mark so huge.

Not sure if you know of this feature in your etrex.

When doing trekking, always enable your Track Log. In the event that you get lost, there is this function known as Trackback which traces your track to the starting point. This is very useful when you are lost.

[redname]

hi,
was jus wondering if its possible to have diff maps in a device?

as in i have a map of s'pore from source A and another from source B, so i'll jus select which map i wanna use on the device?

i'm using etrex legend cx btw

[lfy81]

Luckily the group I am with, is experienced with the area, otherwise sure lost. I am just dissapointed with the GPS accuracy, that's all, especially when trekking for an hour like that, and suddenly the accuracy when "OFF" the mark so huge.

Not sure if you know of this feature in your etrex.

When doing trekking, always enable your Track Log. In the event that you get lost, there is this function known as Trackback which traces your track to the starting point. This is very useful when you are lost.

Bro yoladu, that is easier said than done, the best to do when really lost is to quickly search for the nearest trail. So far been lost once, that's why bought this etrex, to give me a better sense of protection.

The number 1 reason of getting my etrex is locate my location just in case my group overshoot a trail or something, but now knowing that the accuracy can be so "OFF" the mark, I think is better to not to rely too much on it. Or stick to older trails.

My group captain is excellent, she doesn't believe in GPS, has a good sense of direction, and eyesight, and calls my etrex a little T.V--> how cute. . Yes my captain is a she, an aunty actually.

hi,
was jus wondering if its possible to have diff maps in a device?

as in i have a map of s'pore from source A and another from source B, so i'll jus select which map i wanna use on the device?

i'm using etrex legend cx btw

On my Legend HCx it can only recognise 1 "gmapsupp.img" at one time, meaning if I put different version of MFM, only the filename with gmapsupp.img will appear on my Legend HCx.

[fauzee]

Ok my simple review of my etrex Legend HCx, sensitive but not accurate enough.



A clearer and bigger picture in this below link because my picture upload limit is 800pixels

http://img.photobucket.com/albums/v502/ ... llse-1.jpg

Bro..your picture shown that u r 'Disable' the WAAS system..what i know like my 60CSX..Wide Area Augmentation System (WAAS) are very useful to maintain GPS accuracy...maybe like AGPS for GMXT.. source link HERE

[lfy81]

Ok my simple review of my etrex Legend HCx, sensitive but not accurate enough.



A clearer and bigger picture in this below link because my picture upload limit is 800pixels

http://img.photobucket.com/albums/v502/ ... llse-1.jpg

Bro..your picture shown that u r 'Disable' the WAAS system..what i know like my 60CSX..Wide Area Augmentation System (WAAS) are very useful to maintain GPS accuracy...maybe like AGPS for GMXT.. source link HERE

Bro, is this how WAAS looks like? Just now ON my etrex get this.



There is a Red dot near the South, and the blue bars got "D" as well. Must be WAAS signal.

[yoladu]

Bro..your picture shown that u r 'Disable' the WAAS system..what i know like my 60CSX..Wide Area Augmentation System (WAAS) are very useful to maintain GPS accuracy...maybe like AGPS for GMXT.. source link HERE

WAAS coverage is only in north america. It won't work anywhere else.

[silverbeauty]

Below is as extracted from Garmin eTrex manual ( page 44 ) explaining what the "D" alphabet appearing on the signal bar means.

http://www8.garmin.com/manuals/eTrex_Ow ... above_.pdf

WAAS Capability
The eTrex is capable of receiving WAAS (Wide Area Augmentation System) satellite
signals. WAAS is an FAA (Federal Aviation Administration) funded project to improve the
overall accuracy and integrity of the GPS signal for aviation use, but land/sea based users may
also benefit from this system. There are currently two WAAS satellites that can be received
in the U.S.A., one over the Atlantic Ocean and one over the Pacific Ocean, in a geo-stationary
orbit over the equator. Effective use of the WAAS satellite signal may be limited by your
geographic location in relation to those satellites. WAAS is most effective for users in the
continental U.S. WAAS satellite signal reception requires an absolute clear view of the sky and
works best when there are no nearby obstructions such as buildings or mountains. WAAS
satellites are numbered 33 or higher when viewing the sky view on your eTrex. Initial reception
of the WAAS signal may take up to 15–20 minutes, then 1–2 minutes afterwards. When
WAAS differential correction has been received for GPS satellites (numbers 32 or below), a
‘D’ appears in the signal bar of the Advanced Sky View. When enough satellites have received
WAAS differential correction, ‘DIFF’ appears below the ‘Ready to Navigate’ message.

[redname]

On my Legend HCx it can only recognise 1 "gmapsupp.img" at one time, meaning if I put different version of MFM, only the filename with gmapsupp.img will appear on my Legend HCx.

then is there a way to combine these maps?