| Popis: |
Remotely sensed data has proved to be an effective source of information for monitoring changes in land use and land cover. However, remotely sensed images are often degraded due to atmospheric effects or physical limitations. Atmospheric correction reduces the atmospheric influences that are mixed with pure signal of target making it difficult to extract accurate information about the scene or target. In this study, 4 atmospheric correction techniques: namely ATCOR 2, ATCOR 3, FLASSH and empirical line method were used to correct atmospheric effects of the Landsat 5 TM images of Penang Island, Malaysia. The accuracy of the corrected data from each technique was evaluated by comparing with the reference data (ground reference (GR), total suspended solid (TSS), and atmospheric particles less than 10 μm (PM 10)). The results obtained show that ATCOR 3 has the highest correlation coefficient (R) value of 0.6661, ATCOR 2 gives 0.6622, ELM and FLAASH resulted in 0.6484 and 0.6471 respectively for ground reflectance data after correction. Also, the results of TSS data show that ELM has the highest value of R of 0.9195 while FLAASH gives the least value of 0.5575. In addition, for the PM 10 data, ACTOR 3 produces the highest value of 0.5780, while FLAASH gives minimum value of 0.2062. Therefore, the most accurate technique use for GR and PM 10 is ATCOR 3 and TSS is ELM. |
