Obliques: An open approach

Obliques

An open approach

@boyd.xyz/a

Kuwohi (Clingmans Dome), 6,644 ft
Yesterday in the Great Smokies
Webcam archive

Ky GIS Conference, September 25, 2025

Boyd Shearer

Senior Lecturer, UKy Geography 🔗
Assistant Director, Ky DGI (late October) 🔗
outrageGIS mapping 🔗

KyFromAbove Oblique Imagery

Open data for entire state (2022-2024)
Four views for every location in Kentucky
KyFromAbove Explorer 💯 🔗

Raw imagery

How to get it?
Why would you want it?
Gorgeous natural views!
Better sense of scale and context.

Imagine

Walking downtown and asking
"What's on the other side of this building?"
View it on your mobile device.

Challenges

Over 4.4 million images
40 MB – 100 MB per image
At roughly 10k x 15k pixels
TIFFs in the browser?

Opportunities

KyFromAbove on AWS Explorer 🔗
contains the images
but importantly: it provides metadata via spatial layers.

Goals

Make an app that runs on mobile browsers
with minimal tech
and intuitive symbology.
Download full-res by location.

Tech

MapLibreGL JS mapping library🔗
PMTiles for serverless vector tiles🔗

Centroids

Create vector tile of centroids.
2.2 GB becomes 300 MB.
Symbolize by camera orientation.

Attributes needed for intuitive symbology

Time for data munging

to find which way is up

### Make the lookup table
					---
					```python
# List of file paths to FGDBs with image frame feature classes
data = [
    r"Z:\data\oblique_photos_FGDB\KY_KYAPED_2022_Season2_3IN_ImageFrameEO.gdb\KY_KYAPED_2022_Season2_3IN_ImageFrameEO",
    r"Z:\data\oblique_photos_FGDB\KY_KYAPED_2023_Season1_3IN_ImageFrameEO.gdb\KY_KYAPED_2023_Season1_3IN_ImageFrameEO",
    r"Z:\data\oblique_photos_FGDB\KY_KYAPED_2023_Season2_3IN_ImageFrameEO.gdb\KY_KYAPED_2023_Season2_3IN_ImageFrameEO",
    r"Z:\data\oblique_photos_FGDB\KY_KYAPED_2024_Season1_3IN_ImageFrameEO.gdb\KY_KYAPED_2024_Season1_3IN_ImageFrameEO"
]
					```

---

```py
					# Make the empty dictionary to hold results
					fwdFlightDirection = {
    "total": 0,
    "North": 0,
    "South": 0,
    "Other": 0
}
					```
					---
					```python 
# Loop through each FGDB layer and calculate direction from Kappa
					for a in data:
    with arcpy.da.SearchCursor(a, ["ID","Kappa"]) as cursor:
        with arcpy.da.InsertCursor("flight_shot_direction", ["ID", "Direction"]) as insert_cursor:
            for i, row in enumerate(cursor):
                id_parts = row[0].split('/')
                direction = id_parts[1].split('_')[0]
                flight = id_parts[1].split('_')[1]
                shot = id_parts[1].split('_')[2]
                group = f'{flight}_{shot}'
                kappa = row[1]
                fwdFlightDirection["total"] += 1
                if group not in fwdFlightDirection:
                    if kappa > -20 and kappa < 20:
                        fwdFlightDirection[group] = "North"
                        fwdFlightDirection["North"] += 1
                    elif kappa > 160 and kappa < 200:
                        fwdFlightDirection[group] = "South"
                        fwdFlightDirection["South"] += 1
                    elif kappa > -200 and kappa < -160:
                        fwdFlightDirection[group] = "South"
                        fwdFlightDirection["South"] += 1
                    else:
                        fwdFlightDirection[group] = "Other"
                        fwdFlightDirection["Other"] += 1
					```