<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body dir="auto"><div dir="auto"><div dir="auto">Hi Loke</div><div dir="auto"><br></div><div dir="auto">Richard suggested using a NDVI approach which would require data in the Near Infrared (NIR) band. An orthomisaic would contain 3 colour bands, but not the NIR. NDVI provides an understanding of plant greenness and health and may not be suitable for detecting oil palm's. </div><div dir="auto"><br></div><div dir="auto">If you are getting 90 percent plus with your current approach , you may find that you will spend 4 times longer capturing the additional 10 percent. </div><div dir="auto"><br></div><div dir="auto">NIR data,are available from various satellite sensors however, their resolution would not work at the individual plant level.</div><div dir="auto"><br></div><div dir="auto">Some drone sensors record the NIR band.</div><div dir="auto"><br></div><div dir="auto">Kirk Schmidt</div><div dir="auto"></div></div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div id="composer_signature" dir="auto"><div style="font-size:12px;color:#575757" dir="auto">Sent from my Galaxy</div></div><div dir="auto"><br></div></body></html>