Error detection

Page 1 <img data-url='document/error-detection-56ce5f9848a0c.html?page=1' data-page='1' class='cut-thumb lazyload' alt='Page 1: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/1.jpg' width='140' height='200' /> Error detection

Page 2 <img data-url='document/error-detection-56ce5f9848a0c.html?page=2' data-page='2' class='cut-thumb lazyload' alt='Page 2: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/2.jpg' width='140' height='200' /> Types of errors

• Digitizing errors– overshooting– undershooting– polygons do not close– missing data

Page 3 <img data-url='document/error-detection-56ce5f9848a0c.html?page=3' data-page='3' class='cut-thumb lazyload' alt='Page 3: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/3.jpg' width='140' height='200' /> Page 4 <img data-url='document/error-detection-56ce5f9848a0c.html?page=4' data-page='4' class='cut-thumb lazyload' alt='Page 4: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/4.jpg' width='140' height='200' /> An example of horrible digitizing!!!

Contour lines never cross!!

Page 5 <img data-url='document/error-detection-56ce5f9848a0c.html?page=5' data-page='5' class='cut-thumb lazyload' alt='Page 5: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/5.jpg' width='140' height='200' /> “dangling” node

overshooting

Page 6 <img data-url='document/error-detection-56ce5f9848a0c.html?page=6' data-page='6' class='cut-thumb lazyload' alt='Page 6: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/6.jpg' width='140' height='200' /> River digitizedin the wrong direction

Page 7 <img data-url='document/error-detection-56ce5f9848a0c.html?page=7' data-page='7' class='cut-thumb lazyload' alt='Page 7: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/7.jpg' width='140' height='200' /> 3500m

3900 m

Digitizing rivers in the wrong direction creates “canyon” -like features instead of river valleys

Page 8 <img data-url='document/error-detection-56ce5f9848a0c.html?page=8' data-page='8' class='cut-thumb lazyload' alt='Page 8: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/8.jpg' width='140' height='200' /> Types of errors

• Location errors (x,y coordinates)• Edge matching (“seamless”)

Page 9 <img data-url='document/error-detection-56ce5f9848a0c.html?page=9' data-page='9' class='cut-thumb lazyload' alt='Page 9: Error detection' loading='lazy' src='data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+P+/HgAFhAJ/wlseKgAAAABJRU5ErkJggg==' data-src='https://reader036.cupdf.com/reader036/viewer/2022062310/568167ee550346895ddd5c76/html5/thumbnails/9.jpg' width='140' height='200' />

Error detection

Documents

digitizing rivers

river digitizedin

wrong direction3500m

y coordinatesedge