SRTM - Revision history

Chrisg at 17:19, 11 October 2022

2022-10-11T17:19:09Z

Chrisg at 16:12, 29 January 2018

2018-01-29T16:12:29Z

Chrisg: /* Information */

2017-05-17T03:43:24Z

‎Information

Chrisg: /* Information */

2017-05-17T03:41:08Z

‎Information

Chrisg: /* How to use the SRTM data with the Pathloss 4 program. */

2016-12-08T17:01:23Z

‎How to use the SRTM data with the Pathloss 4 program.

Chrisg: /* Information */

2016-12-08T16:59:16Z

‎Information

Chrisg: /* Using SRTM data as Clutter with the Pathloss 5 program. */

2016-12-08T00:37:34Z

‎Using SRTM data as Clutter with the Pathloss 5 program.

Chrisg: /* Information */

2016-12-08T00:36:09Z

‎Information

Chrisg: /* Information */

2016-12-08T00:27:15Z

‎Information

Chrisg: /* Information */

2016-12-08T00:23:09Z

‎Information

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 ==How to download==
-Currently we recommend using the 1" SRTM data available from '''http://e4ftl01.cr.usgs.gov/MEASURES/SRTMGL1.003/2000.02.11/'''. This data is available for the world from latitude 60 degrees south to 60  degrees north. An Earthdata account is required to download this data. To sign up for an Earthdata account, go to '''https://urs.earthdata.nasa.gov/users/new'''.
+The data can be downloaded using the [[FetchSRTM]] tool. This data is available for the world from latitude 60 degrees south to 60  degrees north.
-The files represent 1x1 degree blocks withe naming representing the South Western corner of the block. The data files will have the extension '''.SRTMGL1.hgt.zip'''.
+The files represent 1x1 degree blocks with naming representing the South Western corner of the block. The data files will have the extension '''.SRTMGL1.hgt.zip'''.
-−
-You can also use the download tool described below to download 1x1 degree blocks by coordinates.
-−
-====Pathloss SRTM download tool====
-[[FetchSRTM]] - Tool for finding and downloading terrain data.
-−
-====Older SRTM Site====
-−
-(This is no longer our recommended source for SRTM data)
-−
-The main SRTM download site is found at: '''http://dds.cr.usgs.gov/srtm/'''

@@ Line 6: / Line 6: @@
 ==How to download==
-Currently we recommend using the 1" SRTM data available from '''http://e4ftl01.cr.usgs.gov/SRTM/SRTMGL1.003/2000.02.11/'''. This data is available for the world from latitude 60 degrees south to 60  degrees north. An Earthdata account is required to download this data. To sign up for an Earthdata account, go to '''https://urs.earthdata.nasa.gov/users/new'''.
+Currently we recommend using the 1" SRTM data available from '''http://e4ftl01.cr.usgs.gov/MEASURES/SRTMGL1.003/2000.02.11/'''. This data is available for the world from latitude 60 degrees south to 60  degrees north. An Earthdata account is required to download this data. To sign up for an Earthdata account, go to '''https://urs.earthdata.nasa.gov/users/new'''.
 The files represent 1x1 degree blocks withe naming representing the South Western corner of the block. The data files will have the extension '''.SRTMGL1.hgt.zip'''.

@@ Line 2: / Line 2: @@
 There are 2 ways that SRTM data can be used with Pathloss 5. The data can be configured as a DEM and used for all profile and background generation or it can be used in conjunction with a bare earth DEM (such as [[NED data in GridFloat format]]) as a clutter database. The difference in elevation, when compared to a bare earth DEM is assigned to the clutter height. Both sets of instructions are given below.
-SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tends because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time of year the data was collected, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source (if available), and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.
+SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tends because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time of year the data was collected, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at the antenna sites. It is always recommended to compare against elevations from a bare earth data source (if available), and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.
 ==How to download==

@@ Line 2: / Line 2: @@
 There are 2 ways that SRTM data can be used with Pathloss 5. The data can be configured as a DEM and used for all profile and background generation or it can be used in conjunction with a bare earth DEM (such as [[NED data in GridFloat format]]) as a clutter database. The difference in elevation, when compared to a bare earth DEM is assigned to the clutter height. Both sets of instructions are given below.
-SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tends because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time year the data was collected, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source (if available), and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.
+SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tends because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time of year the data was collected, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source (if available), and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.
 ==How to download==

← Older revision		Revision as of 17:01, 8 December 2016
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	The SRTM data uses the WGS84 datum. Your coordinates will be transformed automatically.		The SRTM data uses the WGS84 datum. Your coordinates will be transformed automatically.

−	In the Pathloss program click "Configure" – "Terrain Database" and select "SRTM" from the drop down list. Click Setup Primary (or Secondary depending on your selection). Click "File" then "BIL-HDR-BLW" and browse to find and load a file with the HGT extension. The program is now setup to use the selected SRTM file.	+	In the Pathloss program click '''''Configure – Terrain Database''''' and select '''''SRTM''''' from the drop down list. Click '''''Setup Primary''''' (or '''''Secondary''''' depending on your selection). Click '''''File''''' then '''''BIL-HDR-BLW''''' and browse to find and load a file with the HGT extension. The program is now setup to use the selected SRTM file.

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-You can multi select file by holding '''''Ctrl''''' or '''''Shift'''''. Click '''''Open''''' and the selected files will be indexed. Pathloss 5 is now configured to use SRTM as clutter. Make sure that the correct Clutter source is selected when generating profiles. These option are shown when generating profiles in the '''''Terrain data''''' section under '''''Configure -Generate profile''''' and also in the '''''Link design rules''''' when creating point to point and point to multi point links.
+You can multi select file by holding '''''Ctrl''''' or '''''Shift''''' while selecting files. Click '''''Open''''' and the selected files will be indexed. Pathloss 5 is now configured to use SRTM as clutter. Make sure that the correct Clutter source is selected when generating profiles. These option are shown when generating profiles in the '''''Terrain data''''' section under '''''Configure - Generate profile''''' and also in the '''''Link design rules''''' when creating point to point and point to multi point links.
-−
 == How to use the SRTM data with the Pathloss 4 program. ==

@@ Line 1: / Line 1: @@
 ==Information==
-There are 2 ways that SRTM data can be used with Pathloss 5. The data can be configured as a DEM and used for all profile and background generation or it can be used as a clutter database, where the difference in elevation, when compared to a bare earth DEM (such as [[NED data in GridFloat format]]) is assigned to the clutter height. Both sets of instructions are given below.
+There are 2 ways that SRTM data can be used with Pathloss 5. The data can be configured as a DEM and used for all profile and background generation or it can be used in conjunction with a bare earth DEM (such as [[NED data in GridFloat format]]) as a clutter database. The difference in elevation, when compared to a bare earth DEM is assigned to the clutter height. Both sets of instructions are given below.
 SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tend because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time year, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source (if available), and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.

@@ Line 1: / Line 1: @@
 ==Information==
-SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tend because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time year, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source, if available, and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this.
+SRTM data is collected by using a stereo radar scan of the earths surface. As a result the data tends to include the trees and buildings as these would be what reflects the radar signal. We say tend because there are variables, especially when dealing with trees. Depending on the tree type (deciduous or evergreen) and the time year, the heights could vary significantly. The radar signal also penetrates into the tree canopy to some degree. These variables need to be kept in mind when using SRTM as clutter. Additional caution needs to be exercised when using SRTM as a DEM, in particular the ground elevations at antenna sites. It is always recommended to compare to elevations from a bare earth data source, if available, and use these for your site elevations. In North America the [[NED data in GridFloat format]] is excellent for this. It is not recommended to use clutter data when using SRTM as the DEM, as this would result in unrealistic clutter heights, almost doubling them in some cases.
 Because of how the SRTM data is collected, there are 2 ways that SRTM data can be used with Pathloss 5. The data can be configured as a DEM and used for all profile and background generation or it can be used as clutter database, where the difference in elevation, when compared to a bare earth DEM (such as [[NED data in GridFloat format]]) is assigned to the clutter height. Both sets of instructions are shown below.