diff --git a/CITATION.cff b/CITATION.cff
index dec1be5..85d27e2 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -3,8 +3,8 @@ message: "If you use this software, please cite it as below."
 
 title: "de:code"
 abstract: "DESHIMA code for data analysis"
-version: 2.14.1
-date-released: 2024-07-06
+version: 2.15.0
+date-released: 2024-07-07
 license: "MIT"
 doi: "10.5281/zenodo.3384216"
 url: "https://github.com/deshima-dev/decode"
diff --git a/README.md b/README.md
index 0fcfbf6..da31a69 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ DESHIMA code for data analysis
 ## Installation
 
 ```shell
-pip install decode==2.14.1
+pip install decode==2.15.0
 ```
 
 ## Quick look
diff --git a/decode/__init__.py b/decode/__init__.py
index a88eeab..710753b 100644
--- a/decode/__init__.py
+++ b/decode/__init__.py
@@ -10,7 +10,7 @@
     "select",
     "utils",
 ]
-__version__ = "2.14.1"
+__version__ = "2.15.0"
 
 
 # submodules
diff --git a/decode/qlook.py b/decode/qlook.py
index 91526aa..f288388 100644
--- a/decode/qlook.py
+++ b/decode/qlook.py
@@ -267,7 +267,7 @@ def raster(
 
         ax = axes[0]  # type: ignore
         plot.data(series, ax=ax)
-        ax.set_title(Path(dems).name)
+        ax.set_title(f"{da.observation}\n({Path(dems).name})")
 
         ax = axes[1]  # type: ignore
         map_lim = max(abs(cube.lon).max(), abs(cube.lat).max())
@@ -277,9 +277,9 @@ def raster(
         ax.set_xlim(-map_lim, map_lim)
         ax.set_ylim(-map_lim, map_lim)
         ax.set_title(
-            "Maximum: "
-            f"dAz = {float(max_pix.lon):+.1f} {cont.lon.attrs['units']}, "
-            f"dEl = {float(max_pix.lat):+.1f} {cont.lat.attrs['units']}"
+            f"Maximum {cont.long_name.lower()} = {cont.max():.2e} [{cont.units}]\n"
+            f"(dAz = {float(max_pix.lon):+.1f} [{cont.lon.attrs['units']}], "
+            f"dEl = {float(max_pix.lat):+.1f} [{cont.lat.attrs['units']}])"
         )
 
         for ax in axes:  # type: ignore
diff --git a/pyproject.toml b/pyproject.toml
index b0d789d..35a6f3b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "decode"
-version = "2.14.1"
+version = "2.15.0"
 description = "DESHIMA code for data analysis"
 authors = [
     "Akio Taniguchi <taniguchi@a.phys.nagoya-u.ac.jp>",