Update app.py

Added working SAT URL samples

app.py

@@ -109,9 +109,21 @@ SAMPLE_URL_CHOICES: Dict[str, List[Tuple[str, str]]] = {
     # SAT: satellite imagery examples
     "sat493m": [
         ("– choose a satellite sample –", ""),
-        ("Blue Marble (NASA)", "https://upload.wikimedia.org/wikipedia/commons/9/9d/The_Blue_Marble_%28remastered%29.jpg"),
-        ("GOES-16 Hurricane Florence (2018)", "https://upload.wikimedia.org/wikipedia/commons/5/5e/Hurricane_Florence_GOES-16_2018-09-12_1510Z.jpg"),
-        ("NASA Earth Observatory: Philippines", "https://eoimages.gsfc.nasa.gov/images/imagerecords/151000/151639/philippines_tmo_2020118_lrg.jpg"),
+        ("Los Angeles — Downtown", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-13162953.111392,4035684.000887,-13162647.363277,4035989.748999&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Chicago — The Loop", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-9755772.575579,5142721.481539,-9755466.827467,5143027.229656&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("San Francisco — FiDi", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-13625779.317660,4549493.705020,-13625473.569543,4549799.453132&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Seattle — Downtown", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-13618135.614829,6041468.060117,-13617829.866717,6041773.808232&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Houston — Downtown", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-10616682.825155,3472648.850537,-10616377.077043,3472954.598652&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Boston — Downtown", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-7910429.838718,5214954.473271,-7910124.090606,5215260.221383&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Miami — Brickell", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-8927271.625996,2970992.633903,-8926965.877884,2971298.382015&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Washington, DC — White House area", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-8575814.169943,4706877.546259,-8575508.421826,4707183.294371&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Philadelphia — City Hall", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-8367523.267865,4858910.795516,-8367217.519750,4859216.543633&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Mexico — Monterrey Macroplaza", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-11167335.176921,2957692.590981,-11167029.428809,2957998.339093&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Mexico — Guadalajara Centro", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-11504728.219772,2353228.571302,-11504422.471660,2353534.319414&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Mexico — CDMX Zócalo", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-11035634.177186,2205781.543740,-11035328.429074,2206087.291852&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Texas — Dallas Downtown", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-10775518.969934,3865535.175922,-10775213.221817,3865840.924038&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Texas — Austin Capitol", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-10880543.446795,3538766.880005,-10880237.698683,3539072.628117&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
+        ("Texas — San Antonio River Walk", "https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-10964394.866824,3429614.803614,-10964089.118712,3429920.551726&bboxSR=102100&imageSR=102100&size=1024,1024&format=jpg&f=image"),
     ],
 }