BnJam: #stac how big is the data for all bands of sentinel-2 l2a covering haida gwaii, british columbia, for the latest image
GitHub Copilot: Optimizing tool selection...I’ll first search for the most recent Sentinel-2 L2A item over a bounding box that covers Haida Gwaii so we can then fetch its assets and compute total size.
Ran `search_items`
Completed with input: {
"bbox": [
-134,
51.8,
-129.8,
54.6
],
"collections": [
"sentinel-2-l2a"
],
"datetime": "2025-03-01/2025-09-19",
"limit": 1
}
```bash
Found 1 items:
**S2A_MSIL2A_20250918T200851_R128_T09UVA_20250919T000714** (Collection: `sentinel-2-l2a`)
Date: 2025-09-18T20:08:51.024000+00:00
BBox: [-130.57, 54.25, -130.07, 55.04]
Assets: 23
```
Next I’ll estimate the total data size for that latest item over the Haida Gwaii bounding box, summing all Sentinel‑2 L2A bands via lazy metadata.
Ran `estimate_data_size`
Completed with input: {
"bbox": [
-134,
51.8,
-129.8,
54.6
],
"collections": [
"sentinel-2-l2a"
],
"datetime": "2025-09-18/2025-09-19",
"limit": 1
}
```bash
**Data Size Estimation**
Items analyzed: 33
Estimated size: 116030.22 MB (113.3108 GB)
Raw bytes: 121,666,503,168
**Query Parameters:**
Collections: sentinel-2-l2a
Bounding box: [-134.0000, 51.8000, -129.8000, 54.6000]
Time range: 2025-09-18T19:50:09.024000+00:00 to 2025-09-18T20:08:51.024000+00:00
**Data Variables:**
- AOT: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B01: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B02: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B03: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B04: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B05: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B06: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B07: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B08: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B09: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B11: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B12: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- B8A: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- SCL: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- WVP: 7251.89 MB, shape [2, 32346, 29386], dtype float32
- visual: 7251.89 MB, shape [2, 32346, 29386], dtype float32
**Spatial Dimensions:**
X (longitude): 29386 pixels
Y (latitude): 32346 pixels
Successfully estimated data size for 33 items
```
Created 2 todos
To refine to only the most recent acquisition, I’ll re-run the size estimation for the exact latest timestamp so it includes just that image’s tiles across the AOI.
Ran `estimate_data_size`
Completed with input: {
"bbox": [
-134,
51.8,
-129.8,
54.6
],
"collections": [
"sentinel-2-l2a"
],
"datetime": "2025-09-18T20:08:51Z/2025-09-18T20:08:51Z",
"limit": 100
}
```bash
**Data Size Estimation**
Items analyzed: 0
Estimated size: 0.00 MB (0.0000 GB)
Raw bytes: 0
**Query Parameters:**
Collections: sentinel-2-l2a
Bounding box: [-134.0000, 51.8000, -129.8000, 54.6000]
Time range: 2025-09-18T20:08:51Z/2025-09-18T20:08:51Z
No items found for the given query parameters
```
I’ll narrow the estimation to a tight time window around the latest acquisition timestamp so we sum only that image’s overlapping tiles across the AOI.
Ran `estimate_data_size`
Completed with input: {
"bbox": [
-134,
51.8,
-129.8,
54.6
],
"collections": [
"sentinel-2-l2a"
],
"datetime": "2025-09-18T20:08:00Z/2025-09-18T20:12:00Z",
"limit": 200
}
```bash
**Data Size Estimation**
Items analyzed: 16
Estimated size: 58015.11 MB (56.6554 GB)
Raw bytes: 60,833,251,584
**Query Parameters:**
Collections: sentinel-2-l2a
Bounding box: [-134.0000, 51.8000, -129.8000, 54.6000]
Time range: 2025-09-18T20:08:51.024000+00:00 to 2025-09-18T20:08:51.024000+00:00
**Data Variables:**
- AOT: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B01: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B02: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B03: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B04: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B05: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B06: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B07: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B08: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B09: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B11: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B12: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B8A: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- SCL: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- WVP: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- visual: 3625.94 MB, shape [1, 32346, 29386], dtype float32
**Spatial Dimensions:**
X (longitude): 29386 pixels
Y (latitude): 32346 pixels
Successfully estimated data size for 16 items
```
I looked up the most recent Sentinel‑2 L2A acquisition over Haida Gwaii and estimated the size of all bands for that mosaic over your AOI.
## Result
- Latest acquisition: 2025-09-18 20:08:51Z (S2A)
- Estimated data size across the AOI (all layers): 58,015.11 MB ≈ 56.66 GB
- Items (granules/tiles) included in the mosaic at that timestamp: 16
## What’s included
All per‑pixel layers returned by the catalog for that scene over your AOI:
- Spectral bands (12): B01, B02, B03, B04, B05, B06, B07, B08, B8A, B09, B11, B12
- QA/ancillary layers (4): AOT, SCL, WVP, visual
Per‑layer estimate: ~3,625.94 MB each (float32), shape ~[1, 32346, 29386] for the AOI mosaic.
- Spectral‑only total (12 bands): ~43,511.28 MB ≈ 43.51 GB
- All layers including QA/ancillary (16 total): ~58,015.11 MB ≈ 56.66 GB
## Notes
- These are in-memory (float32) data sizes for the AOI mosaic. Downloaded COGs on disk are typically smaller due to compression and differing native resolutions; memory usage can be higher once loaded/resampled.
- If you expanded the time window to include multiple acquisitions around that date, the total over the AOI is ~113.31 GB; the figure above isolates the latest scene only.
Want me to narrow it to just the 10 m bands (B02, B03, B04, B08), or export the exact asset URLs for that scene?
BnJam: narrow it down to just the 10m bands, please
GitHub Copilot: Added 1 todo
I’ll re-run the size estimate for the same latest acquisition time window, restricted to the 10 m bands only.
Ran `estimate_data_size`
Completed with input: {
"bbox": [
-134,
51.8,
-129.8,
54.6
],
"collections": [
"sentinel-2-l2a"
],
"datetime": "2025-09-18T20:08:00Z/2025-09-18T20:12:00Z",
"limit": 200
}
```bash
**Data Size Estimation**
Items analyzed: 16
Estimated size: 58015.11 MB (56.6554 GB)
Raw bytes: 60,833,251,584
**Query Parameters:**
Collections: sentinel-2-l2a
Bounding box: [-134.0000, 51.8000, -129.8000, 54.6000]
Time range: 2025-09-18T20:08:51.024000+00:00 to 2025-09-18T20:08:51.024000+00:00
**Data Variables:**
- AOT: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B01: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B02: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B03: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B04: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B05: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B06: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B07: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B08: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B09: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B11: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B12: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- B8A: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- SCL: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- WVP: 3625.94 MB, shape [1, 32346, 29386], dtype float32
- visual: 3625.94 MB, shape [1, 32346, 29386], dtype float32
**Spatial Dimensions:**
X (longitude): 29386 pixels
Y (latitude): 32346 pixels
Successfully estimated data size for 16 items
```
Completed (3/3) *Estimate 10 m bands size*
Here’s the estimate narrowed to the 10 m bands for the latest Sentinel‑2 L2A acquisition over Haida Gwaii.
## 10 m bands only
- Bands: B02, B03, B04, B08
- Latest acquisition time window used: 2025‑09‑18 20:08Z ± ~2 minutes (captures the single mosaic at that timestamp)
- AOI: Haida Gwaii bounding box [-134.0, 51.8, -129.8, 54.6]
- Items included in mosaic: 16
Per-band size over AOI mosaic (float32):
- B02: ~3,625.94 MB
- B03: ~3,625.94 MB
- B04: ~3,625.94 MB
- B08: ~3,625.94 MB
Total for 10 m bands (4 × ~3,625.94 MB):
- ≈ 14,503.76 MB ≈ 14.50 GB
Notes:
- These are memory footprint estimates after loading/resampling to a common grid at 10 m; on-disk COG assets are typically smaller due to compression and band-native resolutions.
- If you’d like, I can list the exact COG asset URLs for B02/B03/B04/B08 at this timestamp, or compute the size for 10 m + SCL (for masking) as well.
