359 reputation
111
bio website
location Atlanta, GA
age 27
visits member for 2 years, 6 months
seen 4 hours ago

Current Ph.D. student working on remote sensing of aerosols for use in health research (I build air pollution maps by fusing satellite data to modeled data and ground observations). Previous work was primarily in disease ecology. Research interests include: Spatial statistics and epidemiology, GIS analysis, fate and transport modeling, big data, and climate change. My preferred tool is R, but can also use Matlab, IDL, arcpy/python, and SAS. For most map-making and smaller-scale analysis I use ArcGIS at work and QGIS if I'm on my laptop.


1d
comment Converting datum?
Also, FYI, the differences in terms of location between the NAD27, NAD83, and WGS84 datums are fairly small (on the order of <100 m in most parts of the world)
1d
comment Converting datum?
So: Define a projection - telling the software what projection and datum your data are in already. Projecting data: Changing the projection and/or datum to something other than the one currently defined
1d
revised In a GeoTiff, what unit are extents in?
Didn't see last part of question
1d
answered In a GeoTiff, what unit are extents in?
1d
comment gdal_contour is missing lines below a certain elevation
Would it be possible for you to post a zoomed in image of the raw elevation values side by side with the contour lines in one of your problem area?
2d
comment gdal_contour is missing lines below a certain elevation
Yea, you can subset w/ gdalwarp, or manually using a gui (qgis or arcgis). But, for the file type you're using, there shouldn't be limits on what can be stored, and if it had run out of memory, it should have thrown an error. Is it possible your data simply cannot support 10 m contours? If you run the tool on a subset of the tiff with values mostly below 500 m, do you get contour lines?
2d
comment gdal_contour is missing lines below a certain elevation
So, these posts about the algorithm are slightly helpful: osgeo-org.1560.x6.nabble.com/…; gis.stackexchange.com/questions/50746/…
2d
awarded  Autobiographer
2d
awarded  Informed
2d
answered GDAL (or other open-source) equivalent of Arc's Point To Raster Tool
2d
comment gdal_contour is missing lines below a certain elevation
Is it just not visualizing some of the lines when you plot it or is the data actually missing? Also, you would probably get drastically increased performance and processing speed if you subset your GeoTif prior to processing and merged everything back together at the end.
2d
comment project hdf file with geospatial_lat and lon in batch process
What kind of hdf files are these (hdf5, hdf-eos, etc.), and what program/language are you looking to use for batch processing? Also, if you're working with NASA data, why didn't you just have them reproject it for you when you ordered it?
May
1
awarded  Critic
May
1
answered What free programs should every GIS user have installed?
May
1
comment What free programs should every GIS user have installed?
ColorBrewer palettes are also available for use in R via the RColorBrewer package
May
1
answered What Makes a Map Beautiful?
May
1
accepted Working around slow processing times in ArcGIS Spatial Analyst functions?
Dec
9
awarded  Yearling
Nov
10
comment Converting datum?
Did you specify the correct datums when converting your coordinates on the csv files to xy point layers before the message came up about converting the datum?
Aug
12
comment all-in-one gis packages for windows 8.1?
Does the OSGEO package not install correctly on Windows 8?