From 2ca5956461fa2b4fa49ab6fabb8fa31d8a192c3d Mon Sep 17 00:00:00 2001
From: Forrest Williams <forrestfwilliams@icloud.com>
Date: Sat, 7 Mar 2026 07:52:05 -0600
Subject: [PATCH 1/3] fix url issue

---
 .gitignore          | 4 ++++
 src/multirtc/dem.py | 2 +-
 tests/test_dem.py   | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/.gitignore b/.gitignore
index 293f627..b4bbe6b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -243,3 +243,7 @@ tags
 
 # Data
 src/multirtc/multimetric/*/
+
+# pixi environments
+.pixi/*
+!.pixi/config.toml
diff --git a/src/multirtc/dem.py b/src/multirtc/dem.py
index c7e818f..7a051a5 100644
--- a/src/multirtc/dem.py
+++ b/src/multirtc/dem.py
@@ -134,7 +134,7 @@ def get_dem_granule_url(lat: int, lon: int) -> str:
     lon_cardinal = 'W' if lon_tens < 0 else 'E'
 
     prefix = f'{lat_cardinal}{np.abs(lat_tens):02d}/{lat_cardinal}{np.abs(lat_tens):02d}_{lon_cardinal}{np.abs(lon_tens):03d}'
-    filename = f'DEM{lat_cardinal}{np.abs(lat):02d}_00_{lon_cardinal}{np.abs(lon):03d}_00_C01.tif'
+    filename = f'DEM_{lat_cardinal}{np.abs(lat):02d}_00_{lon_cardinal}{np.abs(lon):03d}_00_C01.tif'
     file_url = f'{URL}/{prefix}/{filename}'
     return file_url
 
diff --git a/tests/test_dem.py b/tests/test_dem.py
index c6735dc..add86fb 100644
--- a/tests/test_dem.py
+++ b/tests/test_dem.py
@@ -5,7 +5,7 @@
 
 def test_get_granule_url():
     test_url = (
-        'https://nisar.asf.earthdatacloud.nasa.gov/NISAR/DEM/v1.2/EPSG4326/S10/S10_W020/DEMS01_00_W001_00_C01.tif'
+        'https://nisar.asf.earthdatacloud.nasa.gov/NISAR/DEM/v1.2/EPSG4326/S10/S10_W020/DEM_S01_00_W001_00_C01.tif'
     )
     url = dem.get_dem_granule_url(-1, -1)
     assert url == test_url

From e802880565803a6a4ed1ea1c29d32f582a7d67e0 Mon Sep 17 00:00:00 2001
From: Forrest Williams <forrestfwilliams@icloud.com>
Date: Sat, 7 Mar 2026 08:17:53 -0600
Subject: [PATCH 2/3] update changelog

---
 CHANGELOG.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4f1b9e..b8991cc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [PEP 440](https://www.python.org/dev/peps/pep-0440/)
 and uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.5.4]
+
+### Fixed
+* Copernicus DEM for NISAR URLs to fix 404 errors.
+
 ## [0.5.3]
 
 ### Changed

From 11b3fcf0f72a66e5a091bb648bee3341a09a0faa Mon Sep 17 00:00:00 2001
From: Forrest Williams <forrestfwilliams@icloud.com>
Date: Sat, 7 Mar 2026 08:50:04 -0600
Subject: [PATCH 3/3] fix env var auth

---
 CHANGELOG.md             |  1 +
 src/multirtc/__main__.py |  7 +++++++
 src/multirtc/fetch.py    | 15 +++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b8991cc..ab8af55 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### Fixed
 * Copernicus DEM for NISAR URLs to fix 404 errors.
+* Support for EARTHDATA credentials passed as env vars.
 
 ## [0.5.3]
 
diff --git a/src/multirtc/__main__.py b/src/multirtc/__main__.py
index d0273fb..707c9b1 100644
--- a/src/multirtc/__main__.py
+++ b/src/multirtc/__main__.py
@@ -1,10 +1,17 @@
 import argparse
+import os
 
 from multirtc import dem, geocode, multirtc
+from multirtc.fetch import write_credentials_to_netrc_file
 from multirtc.multimetric import ale, point_target, rle
 
 
 def main():
+    username = os.getenv('EARTHDATA_USERNAME')
+    password = os.getenv('EARTHDATA_PASSWORD')
+    if username and password:
+        write_credentials_to_netrc_file(username, password, append=False)
+
     global_parser = argparse.ArgumentParser(
         prog='multirtc',
         description='ISCE3-based multi-sensor RTC and cal/val tool',
diff --git a/src/multirtc/fetch.py b/src/multirtc/fetch.py
index ba3516a..f779632 100644
--- a/src/multirtc/fetch.py
+++ b/src/multirtc/fetch.py
@@ -11,6 +11,21 @@
 from urllib3.util.retry import Retry
 
 
+EARTHDATA_LOGIN_DOMAIN = 'urs.earthdata.nasa.gov'
+
+
+def write_credentials_to_netrc_file(
+    username: str, password: str, domain: str = EARTHDATA_LOGIN_DOMAIN, append: bool = False
+):
+    """Write credentials to .netrc file"""
+    netrc_file = Path.home() / '.netrc'
+    if netrc_file.exists() and not append:
+        logging.warning(f'Using existing .netrc file: {netrc_file}')
+    else:
+        with open(netrc_file, 'a') as f:
+            f.write(f'machine {domain} login {username} password {password}\n')
+
+
 def _get_download_path(url: str, content_disposition: str | None = None, directory: Path | str = '.'):
     filename = None
     if content_disposition is not None: