Hi Michael, The existing roads were probably based on Landsat, the geometric accuracy of which is lower than Spot-6. So if you feel that adjustment is needed, the pre-existing road should probably be adjusted. This would also make it possible to have a consistent geometry for tracing streets and buildings within villages and towns.
Best wishes, Jean-Guilhem Le 04/04/2014 21:05, Michael Judex a écrit : > Dear all, > > I'm just starting to map roads etc. for this job with the SPOT-6 > imagery in NIR. The already existing major roads have a significant > offset to the satellite image (e.g. major road from Macenta to > Voinjama). Should the offset be corrected or is the geometric > correction of the SPOT images not sufficient? > > thanks, > Michael > > Am 04.04.2014 15:26, schrieb Jean-Guilhem Cailton: >> Hi, >> >> Airbus Defence and Space, Geo-Intelligence has donated Spot-6 images, >> acquired between 2013-10-13 and 2013-12-11, that cover a large part of >> the area of the border between Northern Liberia and Southern Guinea, >> including the towns of Voinjama and Kolahun in Liberia, as well as the >> cities of Guéckédou and Macenta in Guinée, and their surroundings. >> >> Job 489 has been set up on the Tasking Manager: >> http://tasks.hotosm.org/job/489 >> >> For the cities of Guéckédou and Macenta, where higher resolution >> Pleiades images are available and that were already mapped (jobs 469 and >> 471), it is better to keep using the Pleiades images as geometrical >> reference, as they have better accuracy (6.5 m CE 90 without GCPs). >> >> Use source=Spot-6, Airbus >> >> Best wishes, >> >> Jean-Guilhem >> >> >> _______________________________________________ >> HOT mailing list >> HOT@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/hot > > > _______________________________________________ > HOT mailing list > HOT@openstreetmap.org > https://lists.openstreetmap.org/listinfo/hot > _______________________________________________ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
