NASA's Shuttle Radar Measurements Program (SRTM) collected elevation imagery for the earth during the 2000 space shuttle mission.
"DTED" represents both a data format and a data source. The DTED data -- a DSM -- comes from the National Geospatial Agency, and it comes in several formats, including DTED format. DTED comes in various resolutions, or "levels". NGA has stated that DTED level 0) (900 meter resolution, interpolated) is publicly available. DTED0 importable into CIVTAK is available in [External Links.
"DTED" represents both a data format and a data source. The DTED data -- a DSM -- comes from NGA, and it comes in several formats, including DTED format.
DTED -- and SRTM come in Levels. Level zero is the coursest level, at about 1 km between posts (more technically, it is 30 arc seconds between posts). DTED1 (and "SRTM1") is 3 arc seconds. DTED2 is 1 arc second, or approximately 30 meters.
DTED data is a Us Department of Defense (DoD) product, which is not widely available, with the exception of DTED0. DTED0 is linked to below.
Shuttle Radar Topology Measurements (SRTM)
SRTM is a Digital Elevation Model (DSM), whereas Digital Terrain Elevation Data (DTED) is a Digital Surface Model (DSM). DSMs represent the elevation of the "Top thing" on the model, such as the tops of trees or buildings. DSMs model the surface of the object.
SRTM also comes in several formats, including DTED format.
DTED Data attempts to model the bare earth, which SRTM measured the elevation that the radar actually saw, including trees and strucutures. For that reason, SRTM and DTED data are not the same in areas that are forested or have structures.
TAK loads elevation models in DTED format.
Importing Elevation Data
Importing elevation data (DTED -- Not 3D models) is done by using the import manager, selecting the file, then selecting "Zipped DTED Directories".
You can download SRTM DSMs from USGS Earth Explorer.
The key to downloading SRTM data in DTED format is that when you get to "View Item Basket" click "Modify Options For All Scenes" and choose "DTED 1 Arc-second". This will give you a zip file. import the Zip File using the Import Manager. When prompted, choose "Zipped DTED directories".
Here's a video that shows how to download the SRTM from the USGS site.
Here are important things to know:
- Choose your data format as SRTM-1 Arc second (similar to DETED Level 2)
- You can't easily download more tha 100 tiles at at time (I had to cut this one tight to keep it under 100)
- Use "Add All Results From Current Page" rather than clicking on each tile.
- "Modify All scenes" to DTED 1-Arc Second.
- Proceed to Checkout and Submit Order
- An email link will be sent to you.
- You need to install the USGS Bulk Downloader to download the SRTM.
- Import with "Import Manager", and select "Zipped DTED".
Import into ATAK
Here's a video showing how to import the Zipped SRTM into ATAK:
ATAK Import Process:
- Select Import Manager
- Navigate to the file(s) you want to import and select them
- Select "Zipped " when asked by ATAK.
- Use the Red X to verify that your DTED is there.
External Data Importable to TAK
- Selected SRTM 1 Arc-second SRTM -- North America originally from Earth Explorer. There are multiple selections there so you can choose the pieces you want.
- SRTM 1 Arc-second SRTM for France downloaded from the video above.