d4c-datapkg-orthoimagery/scripts/ca-bc_vancouver-2022A00055915022_d4c-datapkg-orthoimagery_2022_075mm

Vancouver 2022 Orthoimagery — Download Script

This directory contains the automation script for acquiring the City of Vancouver 2022 Orthophoto Imagery dataset (7.5 cm resolution) from Vancouver Open Data.

What the Script Does

download.sh performs four sequential steps:

1. Download Index — Uses aria2c to fetch the dataset catalogue as a Parquet file from the Vancouver Open Data API.
2. Extract URLs — Queries the Parquet file with duckdb to extract all MrSID image URLs into a plain-text file suitable for batch downloading.
3. Create Output Directory — Ensures the data input directory exists at ../../data/input/ca-bc_vancouver-2022A00055915022_d4c-datapkg-orthoimagery_2022_075mm/ (relative to this script).
4. Download Images — Uses aria2c to download all images in parallel (12 concurrent connections, 4 connections per server) into the data input directory.

Dependencies

The following command-line tools must be installed and available on your PATH:

Tool	Purpose	Install
aria2c	High-speed parallel downloads	sudo apt install aria2
duckdb	Query Parquet files from the CLI	Install guide

Usage

cd scripts/ca-bc_vancouver-2022A00055915022_d4c-datapkg-orthoimagery_2022_075mm
bash download.sh

The script will print progress for each step. Once complete, the downloaded MrSID image files will be located in:

data/input/ca-bc_vancouver-2022A00055915022_d4c-datapkg-orthoimagery_2022_075mm/