Assignment 03

Visibility in terrains

Deadline is 2023-12-19@17:00

Late submission? 10% will be removed for each day that you are late (3 days max)

This is an individual assignment

• Overview
• Test your program with any DEM in EPSG:7415
• The code to use
• Marking
• What to submit and how to submit it

Overview

The aim of this assignment is to implement the line-of-sight algorithm for gridded DTMs, as described in the book.

You will have to develop a Python function that takes as input 2 locations a and b (given in EPSG:7415 coordinates), and the program must return:

• 1 : a sees b, and vice-versa
• 0 : no visibility between the 2 points
• -1: a and/or b are outside the extent of the dataset
• -2: a and/or b are located in a no_data cell

As input, your program should accept any DTM that is in the Netherlands (EPSG:7415). Notice that this DTM can contain no_data values.

You can use a DSM of AHN4 or again use Copernicus GLO-30 gDEM and reproject it.

Your program should work for any GeoTIFF input in that CRS (with different resolutions also), I will test it with different input files.

!!! Notice that you should add +2.0m to the elevation of a, since it acts as a normal person and what they see.

Test your program with any DEM in EPSG:7415

Downloading Copernicus GLO-30 from the official EU website is rather complex, so instead we propose you use OpenTopography.

To reproject them:

gdalwarp -s_srs EPSG:4326+3855 -t_srs EPSG:7415 input.tif output.tif -dstnodata -9999

Notice that -dstnodata -9999 is used to assign no_data to the “edges” during the reprojection.

The code to use

The help code is in the /hw/03/ folder of the GitLab repository of the course.

Marking

What to submit and how to submit it

You have to submit one file: my_code_hw03.py.

Don’t forget to add your name and student-number at the top of the tile, as the comments tell you.

Oh, and no report is necessary.

Upload the file to this Dropbox page.

[last updated: 2023-12-07 15:12]