# SOME DESCRIPTIVE TITLE. # Copyright (C) 2020, OpenDroneMap # This file is distributed under the same license as the OpenDroneMap # package. # FIRST AUTHOR , 2023. # #, fuzzy msgid "" msgstr "" "Project-Id-Version: OpenDroneMap 2.7.0\n" "Report-Msgid-Bugs-To: \n" "POT-Creation-Date: 2021-12-28 10:32-0500\n" "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" "Last-Translator: FULL NAME \n" "Language-Team: LANGUAGE \n" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=utf-8\n" "Content-Transfer-Encoding: 8bit\n" "Generated-By: Babel 2.9.1\n" #: ../../map-accuracy.rst:3 msgid "Map accuracy" msgstr "" #: ../../map-accuracy.rst:5 msgid "" "Accuracy can be defined as the degree or closeness to which the " "information on a map matches the values in the real world. Therefore, " "when we refer to accuracy, we are talking about quality of data and about" " number of errors contained in a certain dataset (Pascual 2011)." msgstr "" #: ../../map-accuracy.rst:8 msgid "**Relative or Local accuracy**" msgstr "" #: ../../map-accuracy.rst:10 msgid "" "Local or relative accuracy can be defined as the degree to which de " "distances between two points on a map correspond to the actually " "distances between those points in the real world." msgstr "" #: ../../map-accuracy.rst:12 msgid "" "Relative accuracy is independent of the location of the map in the world," " so a map can have a high relative accuracy (in size and shape) but its " "position in the world can be shifted (Figure 1)." msgstr "" msgid "Model showing high relative accuracy" msgstr "" #: ../../map-accuracy.rst:18 msgid "" "*Figure 1. Model showing high relative accuracy but misplaced according " "to its real world position*" msgstr "" #: ../../map-accuracy.rst:22 msgid "**Absolute or global Accuracy**" msgstr "" #: ../../map-accuracy.rst:24 msgid "" "Absolute accuracy is the accuracy of the reconstruction in relation to " "its true position on the planet (Pix4D 2019). Figure 2 shows a relative " "and absolute accurate model, as the points are correctly placed according" " to its real world position." msgstr "" msgid "Model showing high absolute accuracy" msgstr "" #: ../../map-accuracy.rst:30 msgid "" "*Figure 2. Model showing high relative and absolute accuracy. Placed " "correctly according to its real world position*" msgstr "" #: ../../map-accuracy.rst:33 msgid "**An Accuracy level for each project**" msgstr "" #: ../../map-accuracy.rst:35 msgid "" "Each project has specific accuracy needs to be met. For instance " "assessing the progress in a construction site or measuring an area " "affected by a fire does not require the use of GCP, since absolute " "accuracy will not impact the decision making process. In the other hand, " "there are tasks on which accuracy is critical, for example project " "compliance evaluations and land title surveying, which require a higher " "relative and absolute accuracy." msgstr "" #: ../../map-accuracy.rst:39 msgid "What to expect" msgstr "" #: ../../map-accuracy.rst:41 msgid "" "In general terms, one can expect the relative accuracy to be in the order" " of 1 to 3 times the average GSD for the dataset. And as for the absolute" " accuracy, one must consider that it is dependent of the GPS unit mounted" " in the UAV but the horizontal accuracy of a standard GPS is usually in " "the range of 2 to 6 meters and the vertical accuracy between 3 to 4 times" " the horizontal accuracy." msgstr "" #: ../../map-accuracy.rst:43 msgid "" "When using GCP, absolute accuracy can be improved to 2.5 times GSD for " "the horizontal accuracy and 4 times the GSD for the vertical accuracy " "(Madawalagama 2016)." msgstr "" #: ../../map-accuracy.rst:45 msgid "" "At a GSD of 1cm, the accuracy is to that of the RTK GNSS, and is within " "1:200 scales according to NSDI & FGDC mapping accuracy standards during " "sub-optimal conditions (Barry 2013)." msgstr "" #: ../../map-accuracy.rst:49 msgid "Aspects impacting map accuracy" msgstr "" #: ../../map-accuracy.rst:51 msgid "**Weather**" msgstr "" #: ../../map-accuracy.rst:53 msgid "" "Weather conditions have direct impact in the photogrammetry results, so " "it is important to consider cloud coverage, wind speed, humidity, sun’s " "altitude and other factors influencing the UAV stability and terrain " "illumination." msgstr "" #: ../../map-accuracy.rst:55 msgid "**Cameras**" msgstr "" #: ../../map-accuracy.rst:57 msgid "" "Bigger and better sensors produce less noise and more clearly focused " "images. Also consider that rolling shutter cameras produce distorted " "images when the UAV is moving, so global or mechanical shutter cameras " "are advised for mapping jobs." msgstr "" #: ../../map-accuracy.rst:60 msgid "**Flight altitude**" msgstr "" #: ../../map-accuracy.rst:62 msgid "" "The higher the flight altitude, the larger the image footprint and GSD. " "The resulting larger GSD the accuracy will be decreased as there will be " "less detail in the recognizable features. When a smaller GSD is required " "an altitude of 3 to 4 times the height of the highest point is " "recommended." msgstr "" #: ../../map-accuracy.rst:65 msgid "**Flight speed**" msgstr "" #: ../../map-accuracy.rst:67 msgid "" "Flight speed have special effect in cameras equipped with rolling " "shutter, while those equipped with global or mechanical shutter tends to " "reduce this effect. UAV equipped with RTK positioning systems are also " "affected with the speed, but with hover at each photo taken, you can get " "very good accuracy. If instead you are moving during each photo take, the" " accuracy is going to be limited by two factors: the speed at which you " "are moving multiplied by the 1 second increments of RTK (Mather 2020)." msgstr "" #: ../../map-accuracy.rst:72 msgid "References" msgstr "" #: ../../map-accuracy.rst:74 msgid "" "Barry, P., & Coakley, R. «Accuracy of UAV photogrammetry compared with " "Network RTK GPS.» Baseline Surveys. 2013. " "http://uav.ie/PDF/Accuracy_UAV_compare_RTK_GPS.pdf (accessed 10 13, " "2020)." msgstr "" #: ../../map-accuracy.rst:76 msgid "" "Drone Deploy. How Do I Use Ground Control Points?: A guide to using " "ground control points with drone mapping software. 5 8, 2017. " "https://www.dronedeploy.com/blog/what-are-ground-control-points-gcps/ " "(accessed 7 9, 2020)." msgstr "" #: ../../map-accuracy.rst:78 msgid "" "Madawalagama, S.L., Munasinghe, N., Dampegama, S.D.P.J. and Samarakoon, " "L. «Low-cost aerial mapping with consumer grade.» 37th Asian Conference " "on Remote Sensing. Colombo, Sri Lanka, 2016." msgstr "" #: ../../map-accuracy.rst:80 msgid "" "Mather, Stephen. OpenDroneMap. 30 de Marzo de 2020. " "https://community.opendronemap.org/t/the-accuracy-of-webodm-using-rtk-" "uavs/3937 (accessed 10 12, 2020)." msgstr "" #: ../../map-accuracy.rst:82 msgid "" "Pascual, Manuel S. GIS Lounge: GIS Data: A Look at Accuracy, Precision, " "and Types of Errors. 11 6, 2011. https://www.gislounge.com/gis-data-a" "-look-at-accuracy-precision-and-types-of-errors/ (accessed 07 09, 2020)." msgstr "" #: ../../map-accuracy.rst:84 msgid "" "Pix4D. «What is accuracy in an aerial mapping project?» Pix4D. 25 de 05 " "de 2019. https://www.pix4d.com/blog/accuracy-aerial-mapping (accessed 10 " "13, 2020)." msgstr "" #: ../../map-accuracy.rst:87 msgid "" "`Learn to edit `_ and help improve `this page " "`_!" msgstr ""