SRTM PROCESSING-ArcGIS

• Preliminary
1. Locate the SRTM documentation at EROS Data Center (ftp://edcftp.cr.usgs.gov/pub/data/srtm/documentation/Notes_for_ARCInfo_users.txt)
2. Copy the aml provided in the above textfile into notepad.
3. Save the file as srtmgrid.aml (check to see if filetype: all files is selected) under c:\arcgis\arcexe83\atool\grid\
• Procedure

1. Download the area of interest:

2. Unzip the elevation file in a new sub-directory

a. Ex. D:\raw\SRTM\new

3. Open a command prompt

a. Start > Run > type 'cmd' and press enter

b. Navigate to \raw\SRTM\new\

c. Type 'dir /b > batch.txt' (a textfile containing filenames will be created at this level)

d. Type 'exit' to close the window

4. Edit the textfile in excel to add variables for our batchfile

a. Open batch.txt in notepad

b. Copy the contents of the batch.txt

c. Open excel and paste the values into the second column

1. In Column C

1. type '=mid(B1,1,7)' in cell C1 and press enter

2. populate the entire column by dragging the collar to the last row occupied (cntrl + n)

2. In column A

1. type 'srtmgrid'

2. populate the entire column by dragging the collar to the last row occupied (cntrl + n)

3. Copy/Paste the populated cells back into the batch.txt making sure you overwrite the previous contents of the textfile.

4. Save the spreadsheet in your working directory

5. Close excel

5. Save the updated batch.txt file as an aml

a. On the command bar

1. Select File > Save As

2. Navigate to your working directory

3. Change the filetype to 'all files'

4. name your textfile batch.aml

6. Run ArcGrid

a. Start Programs ArcGIS > ArcInfo Workstation > Grid

b. Type 'workspace D:\raw\SRTM\new'

c. Type 'show wo' and verify you are in the right location

d. Type '&r batch'

e. DONE!!! The srtmgrid file will now process your hgt files to a georeferenced GRID

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