rossbernet

Reading GeoTiffs

• Introduction
• Reading GeoTiffs With GeoTrellis
  • Reading Locally Part 1: Reading For the First Time
  • Reading Locally Part 2: Expanding Our Vocab
    • Dealing With Compressed GeoTiffs
    • Streaming GeoTiffs
      • Tips for Using This Feature
• Reading in Small Files *(> 4gb)

rossbernet

task: create cost distance raster for each of a series of shapefile for libya using a friction layer derived from open street map road network


steps:
1. obtain street network from OSM. I got mine from here: http://download.gisgraphy.com/openstreetmap/pbf/LY.tar.bz2
then used osmosis to convert pbf to xml.

In arc...
2. reclassify road network such that roads have a value of 1 and non-roads have a value of 5. I set pixel size equal to 200m x 200m

rossbernet

var apple = {'color: 'red', 'name: 'apple'};
var bannana = {'color: 'yellow', 'name: 'bannana'};
var pear = {'color: 'green', 'name: 'pear'};
var fruits = [apple, bannana, pear]

rossbernet

rossbernet

rossbernet

import ee

ee.Initialize()

# Get a download URL for an image.
image1 = ee.Image('srtm90_v4')
path = image1.getDownloadUrl({
    'scale': 30,
    'crs': 'EPSG:4326',
    'region': '[[-120, 35], [-119, 35], [-119, 34], [-120, 34]]'

rossbernet

Goal: Create a web-based weighted raster overlay using open source tools. 
- In the easiest way possible. For a small dataset. In Python

Why: 
1. To learn how this type of analysis might be performed now. 
2. Practice Python and open source tools
3. Understand limitations when datasets get to be too large

rossbernet

There are a number of libaries that support Raster processing in Python.

Most notable:

1. NumPy
2. SciPy
3. Rasterio
4. ArcPy
5. Google Earth Engine
6. MrGEO
7. GDAL

rossbernet

rossbernet

from pyspark import RDD
from geopyspark.context import GeoPyContext

gsc = GeoPyContext(
    master = "local[*]"
    appName = "libya-demo"
)

## Load GeoJSON using Shapley
# TODO: use real shapley syntax