DT Loader - Personal Site of omon

Go to content

Main menu:

DT Loader

Petrel Plugins

DT_Loader  is  Petrel plug-in for loading DT, DTed, DT1, DT2 files into Petrel project.

In 2010 first prototype of DT_Loader has been made in order to load DT files and integrate them into ongoing FDP study for field in Algeria. DT_Loader similar to GeoTIFF_Loader allows to use Petrel build-in conversions as well as ESPG published conversion information from OPG source. Currently coordinates systems from "EPSG Geodetic Parameter Dataset version 6.18.3"  ( http://www.epsg.org/ ) were implement in DT_Loader.
The detailed description of DT-format description can be found in
                       http://dds.cr.usgs.gov/srtm/version2_1/Documentation/MIL-PDF-89020B.pdf


What is DT file?


DT (or DTed) is stands for DIGITAL TERRAIN ELEVATION DATA

USGS has published SRTM maps over internet. There are two levels of maps are available
in DT-1 format (3 arc-seconds sampling) outside of US and
in DT-2 format (1 arc-second) inside US.


How to get DT-file from USGS website

DT-files can be downloaded by EarthExplorer from the following link http://earthexplorer.usgs.gov/
(User have to log-on first to be able to download files).

In "1. Enter Search Criteria" type the area of interest, say "Tunisia" then click "Show".
After that pan and zoom in close to area of your study. Than click "Use Map" button to create the search-boundary.
Next step is to choose the dataset, so click on "Data Sets" and open the tree on "Digital Elevation" and checkout sub-item "SRTM".
Then click on "Results" button to see dt-files available for your area.
The result of query will be shown in the list – in this case we have four files available.





Using "Show footprint"
button user can identify the area of each dt-file.
To download a particular dt-file click on "Download Options" button
.
In pop-up window select "Download these scene in DTED format" then click on "Select Download Option"
On next window click on "Download" button (then "Save").
After that user will be prompted for the location and name to save the DT-file.


Using "Browse.." user can provide the path to dt-file to be loaded. Then "Get Information" allows to see the limits of dt-file in WGS-84 ellipsoid. In order to convert dt-file information user have to provide appropriate conversion information.
By definition df-file CRS is WGS-84 (therefore "Step 1" for dt-file should be WGS84). In "Step 2" user have to select Petrel-project datum and in "Step 3" to select Petrel-project projection system.
DT_Loader allows to load dt-file as points – for that user have to click on "Load DT-file as Points" button.
Additionally DT_Loader allows to re-grid dt-file into a grid in Petrel-project – for that user have to provided gridding information in "Grid geometry" and then click on "ReGrid DT-file to the Project" button.


The result will be stored in Input-tab of Petrel project in folder "DT points"  for points and in folder "DT grid" for grid.

Z value in both cases represents the height from vertical datum of DT-file, which is in this case it E96.

Downloaded DT-fileset examples to test DT_Loader:
                 Aral Sea Project                              (to test dt1-format + WGS84àPulkovo conversion)
                 Caspian Sea Project                       (to test dt1+ WGS84
àPulkovo conversion)
                 Everest Mountain Project                (to test high elevation values)
                 Hambach Open Pit Mine Project     (to test low elevation values)
                 Gulf of Mexico Project                     (to test dt2-format)

Aral Sea Project
Aral Sea is "formerly one of the four largest lakes in the world with an area of 68,000 square kilometres and has been steadily shrinking since the 1960s".

1.
On EarthExplorer pick two points
            44° 0' 0'' N,   58
° 0' 0''E
   and   
47° 0' 0'' N,   62° 0' 0''E
2. The set of 9 DT-files will be provided
3. Coordinate system GK42-10N will be selected on Petrel's Coordinate reference system
4. In DT_Loader we select
   // DT-files are in WGS84 //
       Step1: WGS84

  // Datum Transformation //
       Step2: Pulkovo 1942 [Kazakhstan]

  // Projection //
       Step3: Gauss-Kruger zone 10N  
 

5. The result is 9 grids are shown. Aral Sea Demo Project can be downloaded from here.

Caspian Sea Project
The Caspian Sea is "the largest enclosed inland body of water on Earth by area".

1.
On  EarthExplorer pick two points
            45° 0' 0'' N,   52° 0' 0''E
   and   47° 0' 0'' N,   54° 0' 0''E
2. The set of 5 DT-files will be provided
3. Coordinate system GK42-9N will be selected on Petrel's Coordinate reference system
4. In DT_Loader we select
   // DT-files are in WGS84 //
       Step1: WGS84
  // Datum Transformation //
       Step2: Pulkovo 1942
          [Kazakhstan - Caspian Sea]
  // Projection //
       Step3: Gauss-Kruger zone 9N    

5. The result is 5 grids are shown. Caspian Sea Demo Project can be downloaded from here.

Everest Mountain Project
Mount Everest is "the Earth's highest mountain, with a peak at 8,848 metres (29,029 ft) above sea level",
located
27°59'17'' N,   86°55'31''E on WGS-84
and  X=492652.32m, Y= 3095881.47m in UTM zone 45

1. On  EarthExplorer pick two points
            27° 0' 0'' N,   86° 0' 0''E
   and   29° 0' 0'' N,   88° 0' 0''E
2. The set of 4 DT-files will be provided
3. Coordinate system UTM84-45N will be selected on Petrel's Coordinate reference system
4. In DT_Loader we select
   // DT-files are in WGS84 //
       Step1: WGS84
  // Datum Transformation //
       Step2: WGS84
  // Projection //
       Step3: UTM zone 45N    

5. The result is 4 grids. Everest Mountain Demo Project can be downloaded from here.

Hambach Open Pit Mine Project
"The Tagebau Hambach is a large open-pit mine in Niederzier and Elsdorf, North-Rhine Westphalia, Germany. It is the deepest open pit mine with respect to sea level, where the ground of the pit is 293 metres (961 ft) below sea level", located
50°54'39'' N,   6°30'10''E on WGS-84
and  X=324446.62m, Y= 5642879.54m in UTM zone 32

1. On  EarthExplorer pick two points
            50° 0' 0'' N,   6° 0' 0''E
   and   51° 0' 0'' N,   7° 0' 0''E
2. The set of 1 DT-file will be provided
3. Coordinate system UTM84-32N will be selected on Petrel's Coordinate reference system
4. In DT_Loader we select
   // DT-files are in WGS84 //
       Step1: WGS84
  // Datum Transformation //
       Step2: WGS84
  // Projection //
       Step3: UTM zone 32N    


5. The result of grids per each DT files shown. Hambach Mine Demo Project can be downloaded from here.

Gulf of Mexico Project DT
"The Gulf of Mexico is an ocean basin largely surrounded by the North American continent and the island of Cuba."

1. On  EarthExplorer pick two points
            24° 0' 0'' N,   82° 0' 0''E
   and   28° 0' 0'' N,   80° 0' 0''E
2. The set of 10 DT-files will be provided
3. Coordinate system UTM84-17N will be selected on Petrel's Coordinate reference system
4. In DT_Loader we select
   // DT-files are in WGS84 //
       Step1: WGS84
  // Datum Transformation //
       Step2: WGS84
  // Projection //
       Step3: UTM zone 17N    

5. The result is 10 grids are shown. Gulf of Mexico Demo Project can be downloaded from here.

Feature to consider in next release

It seems to me that it makes sense to improve DT_Loader in the way so it would be possible to grid multiple DT-files into a single grid and populated only within certain boundary polygon. Such feature would allow to fill-in cells between conjugative dt-files (which now appears to be empty grid-nodes) with interpolated value and grid only the area needed for study (within provided boundary polygon).


Updated on 8-January-2013:
Now DT_Loader for Petrel 2012 allows to grid multiple DT-files into single grid without any gaps.

updated on 8-January-2013

 
 
Back to content | Back to main menu