Surveying and mapping with photogrammetry in Drone Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start the drone's camera for photogrammetry.

Drone Programming

drone.camera.[1]()

Drag options to blanks, or click blank then click option'

Aopen

Bactivate

Cenable

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'activate' or 'enable' which may not be valid methods.

Using 'open' which is usually for files, not cameras.

The start() method activates the camera to begin capturing images for photogrammetry.

2fill in blank

medium

Complete the code to set the drone's flight altitude for mapping.

Drone Programming

drone.flight.set_altitude([1])

Drag options to blanks, or click blank then click option'

A100

B50

Cheight

Daltitude

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names instead of numeric values.

Choosing too low or invalid altitude values.

The altitude must be a number representing meters. Here, 100 sets the flight altitude to 100 meters.

3fill in blank

hard

Fix the error in the code to capture images at set intervals.

Drone Programming

drone.camera.capture(interval=[1])

Drag options to blanks, or click blank then click option'

A'5s'

B5

Cfive

D5 seconds

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings like '5s' or '5 seconds' which cause errors.

Using words like 'five' which are invalid.

The interval should be a number representing seconds. Using 5 correctly sets the interval to 5 seconds.

4fill in blank

hard

Fill both blanks to create a dictionary of image filenames and their GPS coordinates.

Drone Programming

image_data = [1]((filename, drone.camera.[2](filename)) for filename in image_list)

Drag options to blanks, or click blank then click option'

Adict

Bget_gps

Ccapture

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'list' instead of 'dict' for the dictionary creation.

Using 'capture' instead of 'get_gps' for GPS data.

We use dict to create a dictionary and get_gps() to get GPS coordinates for each image filename.

5fill in blank

hard

Fill all three blanks to filter images taken above a certain altitude and create a mapping dictionary.

Drone Programming

mapping = [1]: drone.camera.get_gps([2]) for [2] in images if drone.flight.altitude [3] 50}}

Drag options to blanks, or click blank then click option'

Aimg

Bimage

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the dictionary and loop.

Using '<' instead of '>' for altitude comparison.

We use image as the variable name for images, and filter those taken when altitude is greater than 50 meters using >.

Practice

1. What is the main purpose of using photogrammetry in drone surveying?

easy

A. To create maps and 3D models from overlapping photos

B. To control the drone's battery life

C. To improve the drone's flight speed

D. To reduce the number of photos taken

Solution

1. Step 1: Understand photogrammetry basics

   Photogrammetry uses many overlapping photos to build maps and 3D models.

2. Step 2: Identify the main goal in drone surveying

   The goal is to create accurate maps and 3D models from the photos taken by the drone.

3. Final Answer:

   To create maps and 3D models from overlapping photos -> Option A

4. Quick Check:

   Photogrammetry = maps and 3D models [OK]

Hint: Photogrammetry means building maps from photos [OK]

Common Mistakes:

• Confusing photogrammetry with drone battery management
• Thinking photogrammetry speeds up flight
• Assuming photogrammetry reduces photo count

2. Which of the following is the correct syntax to define a flight path list in Python for drone photogrammetry?

easy

A. flight_path = {"point1", "point2", "point3"}

B. flight_path = ("point1", "point2", "point3")

C. flight_path = ["point1", "point2", "point3"]

D. flight_path = "point1", "point2", "point3"

Solution

1. Step 1: Identify list syntax in Python

   Lists use square brackets [] with items separated by commas.

2. Step 2: Check each option

   flight_path = ["point1", "point2", "point3"] uses square brackets and quotes correctly for strings.

3. Final Answer:

   flight_path = ["point1", "point2", "point3"] -> Option C

4. Quick Check:

   List syntax = square brackets [OK]

Hint: Lists use square brackets [] in Python [OK]

Common Mistakes:

• Using parentheses instead of square brackets for lists
• Using curly braces which create sets, not lists
• Leaving out brackets and just separating by commas

3. What will be the output of this Python code snippet used in photogrammetry data processing?

photos = ["img1.jpg", "img2.jpg", "img3.jpg"]
processed = [photo.replace('.jpg', '.tif') for photo in photos]
print(processed)

medium

A. ["img1.tif", "img2.tif", "img3.tif"]

B. ["img1.jpg", "img2.jpg", "img3.jpg"]

C. ["img1.tif.jpg", "img2.tif.jpg", "img3.tif.jpg"]

D. SyntaxError

Solution

1. Step 1: Understand list comprehension with string replace

   Each photo filename has '.jpg' replaced by '.tif'.

2. Step 2: Apply replace to each item

   "img1.jpg" becomes "img1.tif", similarly for others.

3. Final Answer:

   ["img1.tif", "img2.tif", "img3.tif"] -> Option A

4. Quick Check:

   Replace '.jpg' with '.tif' = changed list [OK]

Hint: String replace in list comprehension changes extensions [OK]

Common Mistakes:

• Expecting original list without changes
• Thinking replace adds text instead of replacing
• Confusing syntax causing errors

4. Identify the error in this Python code snippet for planning drone photo overlap:

overlap = 0.7
if overlap > 1:
    print("Overlap too high")
else
    print("Overlap acceptable")

medium

A. Incorrect comparison operator in if statement

B. Missing colon after else statement

C. Variable overlap should be an integer

D. Print statements must be outside if-else

Solution

1. Step 1: Check syntax of if-else statements

   Python requires a colon ':' after else keyword.

2. Step 2: Identify missing colon

   Code has 'else' without a colon, causing syntax error.

3. Final Answer:

   Missing colon after else statement -> Option B

4. Quick Check:

   else: needs colon [OK]

Hint: Always put colon after else in Python [OK]

Common Mistakes:

• Forgetting colon after else
• Thinking overlap must be integer
• Misreading comparison operator

5. You want to generate a dictionary mapping photo filenames to their GPS coordinates after a drone flight. Which Python code correctly creates this dictionary from two lists: photos = ["img1.jpg", "img2.jpg", "img3.jpg"] and coords = [(34.5, -117.2), (34.6, -117.3), (34.7, -117.4)]?

hard

A. photo_coords = [photos, coords]

B. photo_coords = dict(zip(coords, photos))

C. photo_coords = {coords[i]: photos[i] for i in range(len(coords))}

D. photo_coords = {photos[i]: coords[i] for i in range(len(photos))}

Solution

1. Step 1: Understand dictionary creation from two lists

   We want keys as photo names and values as coordinates.

2. Step 2: Check each option

   photo_coords = {photos[i]: coords[i] for i in range(len(photos))} uses dictionary comprehension with matching indexes correctly.

3. Final Answer:

   photo_coords = {photos[i]: coords[i] for i in range(len(photos))} -> Option D

4. Quick Check:

   Dict keys=photos, values=coords [OK]

Hint: Use dict comprehension with index to pair lists [OK]

Common Mistakes:

• Swapping keys and values in dict
• Using zip with wrong order
• Creating list instead of dict