Dear All.
I'm not a surveyor,
I'm just a computer network guy.
my friend ( a surveyor ) ask me to solve his problem.
He use JAVAD Triumph-1, that can receive correction message via :
a. GPRS (by ntrip), or
b. Wifi (by ntrip), or
c. internal UHF, never used .. since it means he will need pricy on-site reference station
The problem is : so many time that he is assigned to do surveying in the area that have no GPRS/Wifi internet access ...so the rover can not reach NTRIP-caster.
My plan to solve this condition is to build Internet router that use UHF, it's doable using some card like this
well .. actualy .. I'll build a device that have internet access over sub gigahertz UHF, and have NTRIP client feature. This router will be the one that request NTRIP-caster, and will decapsulate correction message from inside NTRIP, and throw the result to it's serial port.
My question : Is JAVAD Triumph-1 have a serial port that can received Correction message ? if so .. which one ?
Sincerely
-bino-
Can't the Triumph-1 use its internal NTRIP client to connect to the Internet via WiFi? That would enable you to reduce the complexity of the appliance you're planning to build -- it'd only have to provide a WiFi access point once you get the UHF connection working.
Hi Jim,
Thankyou for your very fast help
> Can't the Triumph-1 use its internal NTRIP client to connect to the Internet via WiFi? That would enable you to reduce the complexity of the appliance you're planning to build -- it'd only have to provide a WiFi access point once you get the UHF connection working.
For short range, yes
I also play with Wifi since late 90's ... I'm pretty sure that we will need quite big wifi omni antenna at the rover side. Wood and trees give quite amount of signal atenuation @ 2.4 Ghz.
Sincerely
-bino-
Hi Adam,
Thankyou for your very fast help
> Not sure about all that, but:
>
> J-Link Lite
J-Link Lite is the first I check for solution.
But it's still need GPRS/3G
What coming to my head is (more/less) like 
The 'OSR' part job :
- Request to NTRIP Server
- Extract RTCM from inside NTRIP
- Send RTCM to Rover Via UHF
Sincerely
-bino-
> I also play with Wifi since late 90's ... I'm pretty sure that we will need quite big wifi omni antenna at the rover side. Wood and trees give quite amount of signal atenuation @ 2.4 Ghz.
That's not what I had in mind. I was thinking like this:
1. TCP/IP over UHF to your black box.
2. TCP/IP inside your custom device to an internal WiFi access point.
3. TCP/IP over WiFi from your custom device to the Triumph internal WiFi client.
4. TCP/IP from the Triumph internal WiFi client to the Triumph internal NTRIP client.
When I rented a Trimble R8, it went via WiFi to an external MiFi that went over GPRS to the cloud. I see your custom device (plus the other end of the UHF connection) as replacing the MiFi. This is also the way I'm hoping to use the Triumph-LS when I test-drive it, as I can run my phone as an access point.
>
> That's not what I had in mind. I was thinking like this:
>
> 1. TCP/IP over UHF to your black box.
> 2. TCP/IP inside your custom device to an internal WiFi access point.
> 3. TCP/IP over WiFi from your custom device to the Triumph internal WiFi client.
> 4. TCP/IP from the Triumph internal WiFi client to the Triumph internal NTRIP client.
>
> When I rented a Trimble R8, it went via WiFi to an external MiFi that went over GPRS to the cloud. I see your custom device (plus the other end of the UHF connection) as replacing the MiFi. This is also the way I'm hoping to use the Triumph-LS when I test-drive it, as I can run my phone as an access point.
understood.
What is the longest range you got betwen your Trimble and Mifi ?
Sincerely
-bino-
> What is the longest range you got betwen your Trimble and Mifi ?
About 3 feet is all I ever needed. The MiFi sat in my shirt pocket, and the Trimble on the pole in my hand.
To answer your questions.
"Is JAVAD Triumph-1 have a serial port that can received Correction message ? if so .. which one ?"
Yes, There are two available Serial COM ports.
COM A and COM B
There is also bluetooth serial option, to keep the device cable FREE.
See photo 
Just something to remember that having all this technology to compensate for no cell or wi fi signal will be for nothing if you are trying to survey more than a certain distance away from the ntrip base station, once you go over 30km or so the accuracies will decrease rapidly, so even though you are getting ntrip corrections streamed to the rover, there will be no fixed gps solution or poor precisions.
There are commercially available uhf to cell bridges that you can buy to do what you proposed already.
Dear leegreen,
Thankyou for your response
Sincerely
-bino-
dear PDOP,
I really appreciate you mention about distance.
Could you please tell more about it ?
When you say 30 km ,
is it the distance from rover to real reference station ? or,
is it the distance from rover to last IP capable node ?
Sincerely
-bino-
> dear PDOP,
>
> I really appreciate you mention about distance.
>
> Could you please tell more about it ?
>
> When you say 30 km ,
> is it the distance from rover to real reference station ? or,
> is it the distance from rover to last IP capable node ?
>
> Sincerely
> -bino-
Its the distance from the rover to the real reference station that counts.
The further away you get from the base station, things like differing atmospheric conditions will affect the GNSS signal and how its received at the different receivers and the satellites that the base station can see will not be the same that the rover can see.
I have got a fix from 120km away from a VRS base station before, it took about 40 minutes to get a fix and it was not accurate enough really for the task at hand.
Our VRS network here has a separate network situated about 1600km away and guys have fixed off it before from down here, but with unusable accuracies.
DEear Pdop
> Its the distance from the rover to the real reference station that counts.
>
> The further away you get from the base station, things like differing atmospheric conditions will affect the GNSS signal and how its received at the different receivers and the satellites that the base station can see will not be the same that the rover can see.
>
> I have got a fix from 120km away from a VRS base station before, it took about 40 minutes to get a fix and it was not accurate enough really for the task at hand.
>
> Our VRS network here has a separate network situated about 1600km away and guys have fixed off it before from down here, but with unusable accuracies.
I really appreciate your response, Thankyou
Ya , some where I read some mm accuracy decrease per some kms.
In my case, I got informed that the physical base station is no more than 60 km.
I'll report back here soon as I got result (good or bad).
Sincerely
-bino-
You may have already seen this, but if not; FWIW:
http://www.javad.com/downloads/javadgnss/how-to/hardware/HPT404BT_GSM_Configuration_Example.pdf
Many others (scroll down to How To section)
http://www.javad.com/jgnss/support/manuals.html
