{"type":"video","version":"1.0","html":"<iframe src=\"https://www.loom.com/embed/80c755dae9d54a7599891094dd1c565f\" frameborder=\"0\" width=\"1146\" height=\"859\" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>","height":859,"width":1146,"provider_name":"Loom","provider_url":"https://www.loom.com","thumbnail_height":859,"thumbnail_width":1146,"thumbnail_url":"https://cdn.loom.com/sessions/thumbnails/80c755dae9d54a7599891094dd1c565f-e081d9ab366aa159.gif","duration":92.147,"title":"2.How accurate should I be when measuring the slope distance (device-target distance) ?","description":"In this Loom I answer how accurate you should be when measuring the slope distance, the device target distance. I explain it acts as a scale factor from measured angles to displacement, so a 1 percent slope distance error leads to about a 1 percent displacement error. For example, a 10 cm measurement error at 10 m shows as about a 0.1 mm error per 10 mm of displacement. The proportional error gets smaller with distance, about 0.1 mm at 10 m, 0.05 mm at 20 m, 0.02 mm at 40 m, and 0.01 mm at 60 m. No action was specifically requested."}