Sunday, January 19, 2014

I need help with the LIDAR images

I keep hearing about the LIDAR images from MA but I have not seen one yet. When I go to upload the *.ZIP file I get something "invalid". Can anyone actually see the image for the Nashua River (I want to see Fitchburg and Leominster) ?

Oops! Forgot the link:

http://www.mass.gov/anf/research-and-tech/it-serv-and-support/application-serv/office-of-geographic-information-massgis/datalayers/lidar.html


Wow! I dove into this a bit further - it being Sunday and it being snowy and all. So you need to upload a Unix utility "7-zip.exe" that works for windows to decompress a *.tif.bz2 file (after having carefully gone to the index to pick a tiny piece of the Fitchburg map to test this on). After some futzing around, since now my PC hard disk is weirdly sub-divided by Windows 8, I locate the new app and try it on the tif.bz2 file. Well it decompresses to somewhere else on the PC. Finally located that using good ole DOS "dir /S" commands and went to open the new tif file. Gotta pick yet another new program (luckily there already is one on this PC) to view TIF files, and FINALLY! the image arrives of a blank page
Maybe my eyes glazed over too soon when reading about MASS-GIS "layers". But I tell you, this is not ready for consumption. Someone is going to have to write a decent wrapper with zoom and scroll.

9 comments :

Anonymous said...

link?

Tim MacSweeney said...

"Luckily, LiDAR data and software for filtering it are available online, and are free! The LiDAR data files are free for download at earthexplorer.usgs.gov. The software is Fusion, which was developed for use by the US Forestry service. It has plenty of functions for analyzing forest canopy coverage and tree size, and can pull out the ground points to make a 3-D surface. Fusion is available at http://www.fs.fed.us/eng/rsac/fusion, along with a tutorial and data examples." - from:
http://secretlandscapes.blogspot.com/2014/01/lidar-works.html

Tim MacSweeney said...

(I am going to see if my 12 year old grandson can explain it to me)

SydneyB said...

I started looking into this on five different occasions, but threw up my hands every time.
A mini-workshop possibility?
If anyone has access to the Journal of Archaeological Science, I found this reference: Rediscovering the lost archaeological landscape of southern New England using airborne Light Detection and Ranging (LiDAR)
by Katharine Johnson. ), Journal of Archaeological Science 43: 9 -20.
SydneyB

pwax said...

Anyone with extra time might try to follow the MAS-GIS instructions. But the data is not in a zoom/scroll state, nor is it easy to overlay with known reference features (such as road maps or topo maps). Until then the data will be pretty useless - a potentially blank image of an unknown place.

darshana patel said...

It’s really very important information on LIDAE, Thank you so much for your valuable time to write this important blog for us lidar survey companies

Anonymous said...

Someone should thank Secret Landscapes for bring our area of interest into the 21st Century. The ability to use gov. laser images for topographical analysis is cutting edge. Thanks and Kudos to Secret Landscapes for figuring this out!

pwax said...

"Secret Landscapes" didn't figure it out. They are reporting on it but are not the only source for the story. Had they actually tried to access the images, they could have mentioned in the article that it was still not ready for prime time.

Anonymous said...

It looks like you need a different program to open the .tiffs than a normal photo editing program. The last line on the MassGIS link has a link to a free program that you can download to view the .tiff files. I downloaded this program and I was able to view the images, they just weren't as detailed as I had hoped. Oh well.

"A free viewer is distributed by Fugro for viewing both LAS point files and the raster GeoTiffs, as well as shapefiles for referencing. "