|
|
|
|
|
|
|
|
|
|
|
|
ERDAS TITAN Forums
|
| Author |
Messages |
|
pgiando
Posts:13
 |
| 11/26/2008 6:07 PM |
|
Hi all,
we are trying to evaluate the stability and performance of TITAN before build up some case study applications with other partners, and to understand if a single mid-user could use TITAN as a platform to easily and rapidly share own geodata, or consume those from other users.
The testing is made in a simple way: importing raster data (eg. orthophotos, topomaps) in TITAN Viewer, Google Earth and various other desktop GIS (eg. ArcGIS, QGIS, ILWIS 3.5) and evaluating the time employed to stream the data completely, and final data resolution.
The results are very different depending on software, and left me rather puzzled. Let's see.
First of all, I used an internet ADSL connection about 5 Mbps download and 512 kbps upload. It is the most widespread connection here in Italy.
In TITAN Viewer, the best results are afforded. Obviously. The raster ecw data you could see on picture "TITAN_Viewer.png" where streamed in about one minute, it corresponds to a nominal scale of 1:100.000.
Google Earth lasted more than 20 minutes (!) to stream the same data and obtain the same view than TITAN Viewer one, with similar resolution.
In ArcGIS the same data where streamed in about 3 secs but with a resolution really really coarse (see picture "TITAN_ArcGIS.png"). The same poor result could be obtained with uDIG.
QGIS and gvSIG instead cannot connect to the WMS service associated to the raster data. The former returns an error in interpreting the GetCapabilities request, gvSIG doesn't connect at all.
So I would like to discuss with you people just two issues:
* is there a way to obtain a WMS layer with a reasonable fine resolution than the one shown in hereby attached pictures?
* could the data streaming with third party applications be improved, to reasonably lower waiting time?
* what could it be the problem of misreading GetCapabilities request for QGIS and gvSIG? Perhaps the WMS version?
The testing of TITAN in external desktop GIS applications is a primary issue to assess, so I think we must discuss about these bottlenecks.
I would appreciate any suggestion or experiences from other people dealing with multiple software platforms and applications.
Cheers,
Pietro |
|
|
|
|
azeller
Posts:91
|
| 12/01/2008 11:22 AM |
|
Hi Pietro,
Thanks for taking the time to detail these performance tests. Here are responses to your questions:
"Google Earth lasted more than 20 minutes (!) to stream the same data and obtain the same view than TITAN Viewer one, with similar resolution. Could the data streaming with third party applications be improved, to reasonably lower waiting time?"
We are making enhancements to TITAN, specifically SpatialBuilder, which will help this out greatly. Look for improvements no later than February 2009.
"QGIS and gvSIG instead cannot connect to the WMS service associated to the raster data. The former returns an error in interpreting the GetCapabilities request, gvSIG doesn't connect at all."
Thank you for alerting us to this, and we found the QGIS issue: It has to do with the http header that QGIS sends. It's the first time we’ve seen the GET line specify the http://server:ip in the request. This was a very easy fix and will work after the auto update in a few days.
“Is there a way to obtain a WMS layer with a reasonable fine resolution than the one shown in hereby attached pictures?”
We are making changes for February for TITAN to support the full resolution of WMS requests.
Best,
Amy |
|
|
|
|
azeller
Posts:91
|
| 12/01/2008 12:28 PM |
|
| Correction: the fix for QGIS will be available in February as well. |
|
|
|
|
pgiando
Posts:13
|
| 12/01/2008 12:36 PM |
|
Thanks for your answers Amy.
Common efforts for testing and benchmarking TITAN is a crucial issue, so I hope others users could contribute to the work.
Cheers,
Pietro |
|
|
|
|
|
| You are not authorized to post a reply. |
|
|
|
ActiveForums 3.7
|
|
|
|
|
|
|
|
|
|
|
|
|
|