Georgeina

Dear Mamadouba, Many thanks for your useful feeedback. Like I said earlier , I am cutting my teeth in Remote sensing and image processing. So when you say the following products contains surface reflectance, i am a bit confused her e. I am working with these products and thought that the bands pixels are submitted with DN values which I now need to convert to TOA reflectance. And someone some where has already provided clues to the algorithm that can be used to convert DNs to TOA. Please could you clarify exactly what you mean? Again with the gap filling, I used the steps outlined by usgs on Landsat page see link: https://landsat.usgs.gov/gap-filling-landsat-7-slc-single-scenes-using-erdas-imagine-TM which has also been confirmed by this video link: Are these methods significantly different from the one you are referring to ? that is usung the gap mask files With kind regards

Ok dear am 2 Many thanks Any videos to follow the tutorial as a beginner? Warm regards

I have data from Landsat TM 4-5, Landsat 7 ETM + and Landsat 8 OLI/TIRS. how can I generate NDVI from these time series data sets What critcial consideratiosn do I need to take or note when carrying out atmospheric corrections and radiometric corrections? What are the important meta data information across all sensor data products when carrying out atrmospheric and geomertic corrections? Your ideas and professional inputs will be greatly appreciated Thanks

Hello Colleagues, I really need help and fast too. I am carrying out a change trajectory change detection analysis looking at how much has changed over the last 25 to 30 years over a local community. My timeline for this review is between 1986 to 2012. I want to generate a NDVI time series over this area so I need at least 15 images to compute NDVI and subject it into a statistical analysis. Landsat data over this area within 1985 to 2000 is very sparse and so there is a huge data inconsistency approx. 5 -6. SPOT 1-5 has about 9 images over this area. As a beginner with these image processing software, I have the following questions: 1. Is it scientifically valid to use available SPOT 1-4 and SPOT 5 images to fuse with corresponding Landsat images of the same year in order to enhance the not too good landsat images of those years? And then build up my time series archives with the good quality Landsat images? And what is the best fusion model? Can I simply use Mosaicking in ERDAS Imagine ? 2. Or do I just carry out necessary radiometric and geometric corrections of the good Landsat and SPOT 1-4 images over the area and then build a time series with data from the two sensors? Will I be committing any breach in known principles of image processing ? 3. I sincerely look forward to your valuable inputs as I have very limited time with my work. 4. Thank you all in advance