nedhorning 24 research notes and 24 wiki edits | Joined about 6 years ago

I live and work from a home office in central Vermont but I work for the American Museum of Natural History's Center for Biodiversity and Conservation in New York City. I've been working with remote sensing and GIS for over 25 years and have an interest in photo-monitoring and am a strong proponent of open source software and the citizen science approach to collecting data.










Automating NDVI calibration

by nedhorning about 4 years ago | 12 | 986 views | 8


Using a RAW image to calibrate a JPEG image

by nedhorning about 5 years ago | 1 | 221 views | 4




Improved DIY NIR camera calibration

by nedhorning about 5 years ago | 49 | 1,723 views | 7


Why a red filter should work well for NDVI

by nedhorning over 5 years ago | 12 | 1,050 views | 5


Red vs. blue filters for NDVI

by nedhorning over 5 years ago | 32 | 2,922 views | 6


Calibrating DIY NIR cameras - part 3

by nedhorning over 5 years ago | 17 | 500 views | 1


Calibrating DIY NIR cameras – part 2

by nedhorning over 5 years ago | 2 | 248 views | 3


Calibrating DIY NIR cameras – part 1

by nedhorning over 5 years ago | 20 | 1,114 views | 2


Balloon mapping of wetlands near Clayton, NY

by nedhorning almost 6 years ago | 5 | 174 views | 1


Characterizing camera sensors – first step

by nedhorning almost 6 years ago | 9 | 139 views | 2


Determining Landsat 8 overpass times

by nedhorning almost 6 years ago | 4 | 2,418 views | 5


Dealing with parallax

by nedhorning over 6 years ago | 7 | 257 views | 0


White balance and NIR photography

by nedhorning over 6 years ago | 15 | 540 views | 2



Software for structure from motion

by nedhorning almost 7 years ago | 1 | 1,763 views | 3


Canon A2200 NIR conversion

by nedhorning almost 7 years ago | 18 | 485 views | 0


Photo monitoring plugin for ImageJ/Fiji

by nedhorning about 7 years ago | 7 | 267 views | 1



Photo Monitoring Plugin For NDVI using ImageJ

by mlamadrid over 3 years ago | 4 | 830 views | 4

New calibration capabilities have been added to the ImageJ/FIJI photo monitoring plugin suite hos...

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How to download and analyze Landsat imagery

by donblair about 5 years ago | 11 | 453 views | 4

This morning, Ned Horning provided a tutorial on downloading Landsat imagery to Cape Cod Baywa...

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How to do the white-balancing for the RED filter?

cagiva asked about 6 months ago

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Seeking DC-area folks interested in building temperature sensors for urban heat island measurement

carohowe asked about about 2 years ago

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Software for mapping trees?

icarito asked about about 2 years ago

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"Test images" for multispectral image processing

warren asked about about 2 years ago

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Detection of heavy metals in plants

JWL asked about over 4 years ago

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View these maps at MapKnitter.org »

Title Creation date Image

Comments

Comment Last activity Moderation
" I can think of two possible reason. The most obvious would be that the illumination changed and the other is that the sensor temperature change. S..." | Read more » 5 months ago
"It's good you discovered that. Yesterday I started to write about the need to subtract the blue band (NIR) from the red band (red + NIR) so you get..." | Read more » 5 months ago
"I used this following dcraw command: dcraw -D -W -4 Image1.ORF to create this image which has been scaled to 16-bit integers: https://drive.googl..." | Read more » 5 months ago
" I have to run out now but will try to make time to check this in the morning. It's also possible it's due to the nature of the filter and after ca..." | Read more » 5 months ago
"Can you post one of your RAW images? I looked at Image1.dng and that shows the Bayer pattern so it needs to go through a debayer process to create ..." | Read more » 5 months ago
"I use RAW pixel values for calibration analysis and since white balance doesn't impact RAW values I don't usually worry about it. If you want to us..." | Read more » 5 months ago
"The calibration coefficients are, in the simplest case, the slope and y-intercept of the linear regression line for wavelength (based on calibratio..." | Read more » 5 months ago
" If you're using them for calibration you should be fine taking photos of the targets every so often. The calibration coefficients shouldn't change..." | Read more » 5 months ago
"I just read over Rob Sumner's RAW guide and see Adobe DNG Converter is free. It also looks like he did some pretty rigorous tests so my previous co..." | Read more » 5 months ago
"The tables look great. Before the end of the week I'll try to compare your converted image with on that I run through dcraw to see if they are simi..." | Read more » 5 months ago
" Hi Corymbia – It’s nice to see some new work in this area. I see that you used the Adobe DNG converter. You might want to look into that to under..." | Read more » 5 months ago
" Nice photos. I suggest using lighting conditions similar to those for the photos you plan to take. Once you get the white balance routine down it'..." | Read more » 6 months ago
"Do the images you acquire using "Auto" mode look the same or very similar to the ones you acquire using the custom white balance? " | Read more » 6 months ago
" Hi: It looks like you are using "Auto" mode when taking the photo. I don't have this camera but I found this web site that might help: https://sup..." | Read more » 6 months ago
"It's worth testing but those cards you link to look promising. From my experience it's the bright target that is more of a problem than the dark ta..." | Read more » 8 months ago
"Hi Jeff - I wasn't sure if you mean varying over time or over the surface. Over time both will vary but from my experience they seem fairly stable ..." | Read more » 8 months ago
"Yes - the author contacted me shortly before posting the blog " | Read more » over 1 year ago
"For the most part I am not able to reliably and accurately validate NDVI calculations. To validate results you would need to have targets with know..." | Read more » over 1 year ago
"Setting up and running an integrating sphere is within your reach for a 12 week course as long as the equipment is working and you have access to s..." | Read more » over 1 year ago
"Hi dannysmith - I’m glad to hear the note was useful to get you started. I find it helpful to plot both red and blue channel regressions but I expe..." | Read more » over 1 year ago
"Hi - This recent paper might be helpful: www.mdpi.com/2073-445X/6/2/38/pdf From my experience satellite based surface temperature works best over f..." | Read more » almost 2 years ago
"Hi Suman - Using Analyze => Measure should work. It's not uncommon to have high pixel values for bright targets. In fact if the exposure isn't s..." | Read more » about 2 years ago
"Hi Suman - The values from 0 - 1 have been scaled from the original image. The reason I do this is that some image pixel values range from 0 - 255 ..." | Read more » about 2 years ago
"Take a look at Open Data Kit: https://opendatakit.org/. I haven't used it in a couple year but know it's still being supported. " | Read more » about 2 years ago

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