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#: ../../../map-accuracy.rst:3 d4e2d7d317d34b208e768f689ad692b0
msgid "Map accuracy"
msgstr ""

#: ../../../map-accuracy.rst:5 674abb654cf7448cac13ea47971e80d2
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 c23ea9314c134c8ba5671054b7e3c057
msgid "**Relative or Local accuracy**"
msgstr ""

#: ../../../map-accuracy.rst:10 35f3324c29ea443497c2fdcd80a55145
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 5463e74ce3b246a4a690fcc476f95536
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 ""

#: ../../../map-accuracy.rst:18 1d4253e1796842319b7dcbd23384343c
msgid ""
"*Figure 1. Model showing high relative accuracy but misplaced according to "
"its real world position*"
msgstr ""

#: ../../../map-accuracy.rst:22 754655b1d1d840fbbc8c2d8980a876fb
msgid "**Absolute or global Accuracy**"
msgstr ""

#: ../../../map-accuracy.rst:24 e5e01529bd0c499aa456f620a7022ef5
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 ""

#: ../../../map-accuracy.rst:30 9d73ff2d96b14f37b5f6166e2baf2695
msgid ""
"*Figure 2. Model showing high relative and absolute accuracy. Placed "
"correctly according to its real world position*"
msgstr ""

#: ../../../map-accuracy.rst:33 b73218309c99474abc6119f6bfffdf61
msgid "**An Accuracy level for each project**"
msgstr ""

#: ../../../map-accuracy.rst:35 1cccb608cda9412c9545ad6c5094fa64
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 cc37e2d221b5438597d9284f2f6b18ff
msgid "What to expect"
msgstr ""

#: ../../../map-accuracy.rst:41 0a236f8f8a584a588a68484240ee6551
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 60659f189c6143b6bd94cb23d28105d6
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 7f9656e94e544adf807d480168874da7
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 3e9dd6b536884dd38b143069f710f1ab
msgid "Aspects impacting map accuracy"
msgstr ""

#: ../../../map-accuracy.rst:51 fedd030db34543209cfa5ee6ef5e6196
msgid "**Weather**"
msgstr ""

#: ../../../map-accuracy.rst:53 dd1b686e9e6b413c96a22b6509f9d88d
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 dd609d1a79b64f2590b9d786fa83e5f1
msgid "**Cameras**"
msgstr ""

#: ../../../map-accuracy.rst:57 c3cb5f9cfee84481a72bfcb66a85f17b
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 e4f17c5a5c184b5691fa3a8c08bb8543
msgid "**Flight altitude**"
msgstr ""

#: ../../../map-accuracy.rst:62 e6a7b31d71664586a04a8fdd54f2001d
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 1555b7ec782a49c6a7460f0e32d578e0
msgid "**Flight speed**"
msgstr ""

#: ../../../map-accuracy.rst:67 2eb90c4a9e41400d94a560217cfc9e96
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 d2ef9f75f3624fd18cc2d2e7e0f9afee
msgid "References"
msgstr ""

#: ../../../map-accuracy.rst:74 9b8c9e6151824c24a592ec6ae333ff61
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 54475a5460a74936b892b63f462125f9
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 3c130fce6ff74f019cbe7244f8138545
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 151ceb4c0fd84418b73fd6a3717038e3
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 6f51c9cc28e6453ab07e036fa6e37a03
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 0bc80ba7d78f4075b5ea484cdbdb767f
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 fb3f3b6f21c547389dd446af2ff2d1e0
msgid ""
"`Learn to edit <https://github.com/opendronemap/docs#how-to-make-your-first-"
"contribution>`_ and help improve `this page "
"<https://github.com/OpenDroneMap/docs/blob/publish/source/map-"
"accuracy.rst>`_!"
msgstr ""
