Merge pull request #712 from nsidc/fix-nodata-overviews-gravity-geoid…

…-layers Fix geoid and gravity anomaly layers' nodata value in overviews
nsidc · Aug 8, 2023 · 0def693 · 0def693
2 parents 47bcdc9 + 969a0f6
commit 0def693
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -177,6 +177,11 @@
 - Switch back to `.qgs` project file from `.qgz`; There is [an
   issue](https://github.com/qgis/QGIS/issues/42033) conveniently opening `.qgz`
   project files in OSX for some versions of QGIS `3.16.x`.
+- Fix issue with "Geophysics/" layers displaying nodata values at some zoom
+  levels:
+  - "Bouguer gravity anomaly (2km)"
+  - "Faye (free-air) gravity anomaly (2km)"
+  - "Geoid model (2km)"
 
 
 # v2.0.0rc6 (2022-03-17)

diff --git a/qgreenland/config/cfg-lock.json b/qgreenland/config/cfg-lock.json
@@ -18394,6 +18394,8 @@
                     "EPSG:3413",
                     "-r",
                     "bilinear",
+                    "-dstnodata",
+                    "-9999",
                     "-tr",
                     "2000",
                     "2000",
@@ -18485,6 +18487,8 @@
                     "EPSG:3413",
                     "-r",
                     "bilinear",
+                    "-dstnodata",
+                    "-9999",
                     "-tr",
                     "2000",
                     "2000",
@@ -18576,6 +18580,8 @@
                     "EPSG:3413",
                     "-r",
                     "bilinear",
+                    "-dstnodata",
+                    "-9999",
                     "-tr",
                     "2000",
                     "2000",

diff --git a/qgreenland/config/helpers/layers/gravity_anomalies_geoid.py b/qgreenland/config/helpers/layers/gravity_anomalies_geoid.py
@@ -38,6 +38,12 @@ def _make_layer(
                 input_file="{input_dir}/" + filename,
                 output_file="{output_dir}/" + filename,
                 reproject_args=[
+                    # The source nodata value is 1.70141e+38. This value is not
+                    # correctly set in the overviews (added in the step below),
+                    # so override it here as -9999. See
+                    # https://github.com/OSGeo/gdal/issues/8187.
+                    "-dstnodata",
+                    "-9999",
                     # Source data is 0.02x-0.02 degrees resolution. Rene noted in
                     # his email to QGreenland on 2021-01-22 that the geoid and
                     # gravity anomaly grids are 2km resolution.