scaled = (actual + shift) * scale + offset actual = (scaled - offset) / scale - shift
The tables below reflect the above equations. However, for the sake of efficiency, these equations are not actually implemented in the scaling code. In the scaling code, the "scale", "offset", and "shift" parameters are combined into just a "scale" and "offset" parameter. See the AVHRR Global Scaling (IMPLEMENTED METHOD) table for more details.
Field Actual Shift Shifted ---------------------------------------------- SatZen: -180 to 180 90 0 to 180 SolZen: 0 to 180 0 0 to 180 RelAz: -180 to 180 180 0 to 360 Reflectance: 0 to 100 0 0 to 100 Radiance: 0 to 540 0 0 to 540 Thermal: 160 to 340 -160 0 to 180 NDVI: -1 to 1 1 0 to 2 | BYTE | 10BIT Field | scale offset min/max Field | scale offset min/max ------------------------------------ ------------------------------------- SatZen: | 1.0 10.0 10/190 SatZen: | 1.0 10.0 10/190 SolZen: | 1.0 10.0 10/190 SolZen: | 1.0 10.0 10/190 RelAz: | 0.5 10.0 10/190 RelAz: | 1.0 10.0 10/370 Reflectance: | 1.0 10.0 10/110 Reflectance: | 10.0 10.0 10/1010 Radiance: | 0.454 10.0 10/255 Radiance: | 1.874 10.0 10/1022 Thermal: | 1.359 10.0 10/255 Thermal: | 5.602 10.0 10/1018 NDVI: | 100.0 10.0 10/210 NDVI: | 100.0 10.0 10/210 | 16BIT | 32BIT Field | scale offset min/max Field | scale offset min/max ------------------------------------- ------------------------------------ SatZen: | 10.0 10.0 10/1810 SatZen: | 100.0 10.0 10/18010 SolZen: | 10.0 10.0 10/1810 SolZen: | 100.0 10.0 10/18010 RelAz: | 10.0 10.0 10/3610 RelAz: | 100.0 10.0 10/36010 Reflectance: | 10.0 10.0 10/1010 Reflectance: | 100.0 10.0 10/10010 Radiance: | 10.0 10.0 10/5410 Radiance: | 100.0 10.0 10/54010 Thermal: | 10.0 10.0 10/1810 Thermal: | 100.0 10.0 10/18010 NDVI: | 100.0 10.0 10/210 NDVI: | 100.0 10.0 10/210 | REAL Field | scale offset min/max ------------------------------------ SatZen: | 1.0 10.0 10/190 SolZen: | 1.0 10.0 10/190 RelAz: | 1.0 10.0 10/370 Reflectance: | 1.0 10.0 10/110 Radiance: | 1.0 10.0 10/550 Thermal: | 1.0 10.0 10/190 NDVI: | 100.0 10.0 10/210
scaled = (actual * scale) + offset actual = (scaled - offset) * unscale where: unscale = 1.0 / scaleThe tables below reflect the above equations. However, the above equations were derived from the more explicit equations:
scaled = (actual + shift) * scale + offset actual = (scaled - offset) / scale - shiftFor the sake of efficiency, the "scale", "offset", and "shift" parameters were combined into just a "scale" and "offset" parameter. This more efficient set of equations are what is actually implemented in the scaling code. See the AVHRR Global Scaling ( THEORETICAL METHOD) table for more details.
Field Actual Used ---------------------------------------- SatZen: -180 to 180 -90 to 90 SolZen: 0 to 180 0 to 180 RelAz: -180 to 180 -180 to 180 Reflectance: 0 to 100 0 to 100 Radiance: 0 to 540 0 to 540 Thermal: 160 to 340 160 to 340 NDVI: -1 to 1 -1 to 1 | BYTE | 10BIT Field | scale offset min/max Field | scale offset min/max ------------------------------------ ------------------------------------ SatZen: | 1.0 100.0 10/190 SatZen: | 1.0 100.0 10/190 SolZen: | 1.0 10.0 10/190 SolZen: | 1.0 10.0 10/190 RelAz: | 0.5 100.0 10/190 RelAz: | 1.0 190.0 10/370 Reflectance: | 1.0 10.0 10/110 Reflectance: | 10.0 10.0 10/1010 Radiance: | 0.454 10.0 10/255 Radiance: | 1.874 10.0 10/1022 Thermal: | 1.359 -207.44 10/255 Thermal: | 5.602 -886.32 10/1018 NDVI: |100.0 110.0 10/210 NDVI: |100.0 110.0 10/210 | 16BIT | 32BIT Field | scale offset min/max Field | scale offset min/max ------------------------------------ ------------------------------------ SatZen: | 10.0 910.0 10/1810 SatZen: | 100.0 9010.0 10/18010 SolZen: | 10.0 10.0 10/1810 SolZen: | 100.0 10.0 10/18010 RelAz: | 10.0 1810.0 10/3610 RelAz: | 100.0 18010.0 10/36010 Reflectance: | 10.0 10.0 10/1010 Reflectance: | 100.0 10.0 10/10010 Radiance: | 10.0 10.0 10/5410 Radiance: | 100.0 10.0 10/54010 Thermal: | 10.0 -1590.0 10/1810 Thermal: | 100.0 -15990.0 10/18010 NDVI: | 100.0 110.0 10/210 NDVI: | 100.0 110.0 10/210 | REAL Field | scale offset min/max ------------------------------------ SatZen: | 1.0 100.0 10/190 SolZen: | 1.0 10.0 10/190 RelAz: | 1.0 190.0 10/370 Reflectance: | 1.0 10.0 10/110 Radiance: | 1.0 10.0 10/550 Thermal: | 1.0 -150.0 10/190 NDVI: | 100.0 110.0 10/210