1 00:00:03,080 --> 00:00:05,100 Two Instruments That Make It All Happen 2 00:00:05,100 --> 00:00:07,770 There are two instruments aboard Landsat 9. 3 00:00:07,770 --> 00:00:10,780 OLI- 2 is all about light. 4 00:00:10,780 --> 00:00:12,210 5 00:00:12,210 --> 00:00:16,920 Once in orbit, OLI-2 collects sunlight reflected off Earth’s surface. 6 00:00:16,920 --> 00:00:18,200 7 00:00:18,200 --> 00:00:20,290 The light passes through a set of filters, 8 00:00:20,290 --> 00:00:22,990 to separate out nine specific wavelength bands, 9 00:00:22,990 --> 00:00:26,360 in visible and infrared frequencies. 10 00:00:26,360 --> 00:00:29,840 Each band provides different pieces of information about 11 00:00:29,840 --> 00:00:31,840 what is down on the surface. 12 00:00:31,840 --> 00:00:32,710 13 00:00:32,710 --> 00:00:36,260 The second instrument aboard Landsat 9, called TIRS-2, 14 00:00:36,260 --> 00:00:38,840 collects thermal infrared wavelengths, 15 00:00:38,840 --> 00:00:43,090 or temperature signatures emitted by the Earth itself. 16 00:00:43,090 --> 00:00:47,573