Night Light of Guyancourt (Île-de-France) from space (France) Src. Average luminocity for 10x10km area is 70.2202% and for 50x50km: 55.1593%.
Square area 10x10 km:
 19.32%
 19.32% 19.6%
 19.6% 6.39%
 6.39% 4.26%
 4.26% 11.08%
 11.08% 10.51%
 10.51% 8.66%
 8.66% 15.63%
 15.63% 4.55%
 4.55% 0%
 0% 0%
 0%Square area 50x50 km:
 23.48%
 23.48% 13.26%
 13.26% 4.27%
 4.27% 3.9%
 3.9% 4.69%
 4.69% 3.92%
 3.92% 5.06%
 5.06% 4.25%
 4.25% 5.79%
 5.79% 9.19%
 9.19% 22.19%
 22.19%Clear (daylight) street map image can be seen on geolist.org.
Map coordinates:
49° 14' 4.5" North, 1° 22' 14.9" East
48° 46' 24" North, 2° 4' 26.1" East
48° 18' 28.1" North, 2° 46' 37.4" East
Some cities around Guyancourt sort by population:
• Saint-Quentin-en-Yvelines
		4 km =2.5 mi,  267°
267°
• Montigny-le-Bretonneux
		3 km =1.9 mi,  255°
255°
• Trappes
		4.1 km =2.5 mi,  271°
271°
• Saint-Cyr-l’École
		2.8 km =1.7 mi,  351°
351°
• Voisins-le-Bretonneux
		2.4 km =1.5 mi,  223°
223°
• Bois-d’Arcy
		4.7 km =2.9 mi,  308°
308°
• Magny-les-Hameaux
		3.4 km =2.1 mi,  195°
195°
• Buc
		3.8 km =2.4 mi,  85°
85°
Sources (retrieved 2019-11-25):
» Earth at Night: Flat Maps 2012, 2016