Add some NISAR exploration scripts

Author: maxrjones

.gitignore

@@ -82,3 +82,6 @@ site/*
 
 # uv lock files
 uv.lock
+
+# script output
+*.html

docs/examples/nisar/README.md

@@ -0,0 +1,69 @@
+# NISAR Data Access Examples
+
+These scripts demonstrate obspec-utils for accessing NASA NISAR data via HTTPS with Earthdata authentication.
+
+## Prerequisites
+
+- NASA Earthdata account ([register here](https://urs.earthdata.nasa.gov/users/new))
+- `earthaccess` configured with your credentials
+
+## Scripts
+
+### `virtualize.py` (not functional)
+
+Minimal example showing how to create a virtual datatree from a remote NISAR file.
+
+> **Note:** This example currently fails due to upstream limitations:
+> 1. The "crosstalk" variable has a complex dtype not supported by Zarr
+> 2. `drop_variables` doesn't yet work for variables in nested HDF5 groups
+>
+> Fixes are needed in [VirtualiZarr](https://github.com/zarr-developers/VirtualiZarr).
+
+```bash
+uv run --script docs/examples/nisar/virtualize.py
+```
+
+### `benchmark.py`
+
+Compare obspec-utils readers against fsspec for performance.
+
+```bash
+uv run --script docs/examples/nisar/benchmark.py
+uv run --script docs/examples/nisar/benchmark.py --block-size 32
+```
+
+### `waterfall.py`
+
+Visualize HTTP range requests as a waterfall chart (byte position vs time).
+
+```bash
+uv run --script docs/examples/nisar/waterfall.py
+uv run --script docs/examples/nisar/waterfall.py --block-size 8
+uv run --script docs/examples/nisar/waterfall.py --output my_waterfall.html
+```
+
+### `analyze.py`
+
+Analyze request patterns with timeline, size histogram, and byte coverage stats.
+
+```bash
+uv run --script docs/examples/nisar/analyze.py
+uv run --script docs/examples/nisar/analyze.py --block-size 16
+uv run --script docs/examples/nisar/analyze.py --output my_analysis.html
+```
+
+### `layout.py` (not functional)
+
+Visualize file layout showing where data chunks vs metadata are located. Uses VirtualiZarr to extract chunk locations from the manifest.
+
+```bash
+uv run --script docs/examples/nisar/layout.py
+uv run --script docs/examples/nisar/layout.py --output my_layout.html
+```
+
+## Output
+
+- `benchmark.py` prints results to stdout
+- `waterfall.py` generates `waterfall.html`
+- `analyze.py` generates `analyze.html`
+- `layout.py` generates `layout.html`