| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| cfastie | "You are overlooking something hidden. The edit button is in the "Follow" "Like" bar at upper right. Chris " | Read more » | over 8 years ago | |||
| cfastie | "Another excellent lesson. But part of that lesson is that 25 mph winds are a problem that can be solved with money. A big soft kite like the Parafo..." | Read more » | over 8 years ago | |||
| cfastie | "That's a good description of what the Rosco blue filter does. Both the blue and the red channels will have a mixture of visible and NIR light. The ..." | Read more » | over 8 years ago | |||
| cfastie | "The tools of environmental science have been available to journalists for as long as there has been environmental science. Environmental scientists..." | Read more » | over 8 years ago | |||
| cfastie | "I have wondered about how important it is to really extract the plant pigments for this type of absorbance observation. If you had an intact transp..." | Read more » | over 8 years ago | |||
| cfastie | "This is a great summary of sensor journalism, a topic that has puzzled me for a while. Selecting, assembling, deploying, and monitoring sensors, as..." | Read more » | over 8 years ago | |||
| cfastie | "I just printed a few camera trays without support and the beads did not droop enough to make a difference. The result is not always so good but I h..." | Read more » | almost 9 years ago | |||
| cfastie | "I guess you are right about the two peaks. I was thinking that you had captured the lesser peak of Chlorophyll a shown here at about 410 nm: Tha..." | Read more » | almost 9 years ago | |||
| cfastie | "Ah, those were the days when the boy might have considered joining me for KAP. Enjoy it while you can. It sounds like you did some useful experi..." | Read more » | almost 9 years ago | |||
| cfastie | "That's a good idea to use only one color of light. It can make it easier to interpret the result. Your result is very consistent with the two peaks..." | Read more » | almost 9 years ago | |||
| cfastie | "other areas (not foliage) showed values between 0.2 and 0.9 and I don't know why, since there is no photosynthesis occuring there. Getting high ND..." | Read more » | almost 9 years ago | |||
| cfastie | "Do you know how well synchronized the photo pairs are? Do you have to start them both taking photos at the same time, or synchronize their clocks? ..." | Read more » | almost 9 years ago | |||
| cfastie | "The NDVI image in my last comment was made by stretching only the NIR channel. The default is to stretch both NIR and VIS and that usually works we..." | Read more » | almost 9 years ago | |||
| cfastie | "Both NDVI images look good. Both seem to have some biological meaning and both have reasonable NDVI values in areas that are shady which is very go..." | Read more » | almost 9 years ago | |||
| cfastie | "Hi Parth, The three methods of computing NDVI all do the same thing. They do the same math (NIR-VIS)/(NIR+VIS) on each pixel. They are equally rel..." | Read more » | almost 9 years ago | |||
| cfastie | "Rayishido, I assume the orangish photo was taken with the PiNoir camera with a blue filter. By calibration I think you mean you used the AWB_gains..." | Read more » | almost 9 years ago | |||
| cfastie | "Threaded lamp pipe comes in zinc plated steel, but I don't think we will find stainless. Here are two bulk suppliers of nipples: http://www.antique..." | Read more » | almost 9 years ago | |||
| cfastie | "Threaded lamp pipe. 3/8" OD. $3.27 for 8 pieces http://www.homedepot.com/p/Westinghouse-8-Assorted-Nipples-7015000/204836020?MERCH=REC-_-PIPHoriz..." | Read more » | almost 9 years ago | |||
| cfastie | "Any hollow bolt can be a cable penetrator. These cost $1.20 apiece, but you also need two nuts and rubber washers. The hole is only 2.3 mm in diame..." | Read more » | almost 9 years ago | |||
| cfastie | "Yes Nalgene. Remember when BPA drove all responsible mothers and other tree huggers to abandon Nalgene water bottles? I have a box in the shed ful..." | Read more » | almost 9 years ago | |||
| cfastie | "How many sensors can a Riffle monitor gracefully? Considering that the typical sensors that might be used are cheap and maybe unreliable, does it ..." | Read more » | almost 9 years ago | |||
| cfastie | "The NDVI image looks good. Are they castor beans? The plants have higher NDVI values than soil or sky, but within the plants, variation in NDVI is ..." | Read more » | almost 9 years ago | |||
| cfastie | "Hi Rayishido, Nice Pi photos. Claytonb is correct about the shadows. It's a common artifact for dark areas to have very high NDVI values. In your ..." | Read more » | almost 9 years ago | |||
| cfastie | "Parth, The dual band dichroic filters are very expensive and seem to work best if installed inside the camera. They should provide better results ..." | Read more » | almost 9 years ago |