Accuracy of Counting Coconut Palms with VHR Image Data KB. Kataebati GSD – Geoscience Division
Texture Information IKONOSGeoEye WorldView-2
1 st Step - Palm Resource Mapping with VHR Satellite Images Using World View-2 resolution 50cm A.Separation of coconut palm from other vegetation B.Density stratification C.Selection of Plots D.Digitising E.Counting of palms per hectare Remote Sensing Application Field Work Field Work
Density Classes Scattered coconut: palms/hectare Scattered coconut: palms/hectare Semi Dense: 50 – 150 palms/hectare Semi Dense: 50 – 150 palms/hectare Dense Coconut > 150 palms/hectare Dense Coconut > 150 palms/hectare
Digitising
Counting Palms in Plots Placing a dot on top of every visible palm Placing a dot on top of every visible palm Digital overlay with grid and counting in MapInfo (GIS software) dots per grid cell Digital overlay with grid and counting in MapInfo (GIS software) dots per grid cell Transfer to Access Transfer to Access
The number of palms is counted through a semi automatic process connecting MapInfo GIS software with Access Database software Transfer MapInfo (GIS) Access Database
Establishment and Identify Plot in the Field using GPS GPS - Base Station Communicating with Satellite GPS- Rover (recording) Plot line
Examples of Overlaying GPS Plot over the Image Plot Established from Satellite Image Identified by GPS
Mismatch of Plot Outlay GPS accuracy of 80 cm does not apply for way points GPS accuracy of 80 cm does not apply for way points Solution → new image interpretation for field plots Solution → new image interpretation for field plots
Comparison Between Image interpretation and in Reality
Result Images VS Reality 100 plots investigated 100 plots investigated Dense coconut, 70 plots 10.6% underestimated Dense coconut, 70 plots 10.6% underestimated Semi dense coconut 14 plots 4.4% underestimated Semi dense coconut 14 plots 4.4% underestimated Scattered coconut plots 16 plots correct image interpretation Scattered coconut plots 16 plots correct image interpretation
Dense Coconut Palm
Conclusion Factor 10.6% and 4.4% is incorporated in code to calculate palms per hectare Factor 10.6% and 4.4% is incorporated in code to calculate palms per hectare Accuracy will be improved with additional investigations Accuracy will be improved with additional investigations
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