Docs · Exporting data

Exporting Photon Ledger data

Photon Ledger keeps a tidy index of every sub-frame it scans. On the Pro tier you can take that index out of the app and into anywhere else you work — spreadsheets, notebooks, BI dashboards, or your own scripts — via CSV export.

What you can export

Everything in PL is built on the same underlying index of FITS headers. Three views of that index are useful outside the app:

Frame-level metadata — one row per sub-frame. Path, target, filter, exposure, image type, date, instrument, telescope, focal length, binning, gain, sensor temperature. The full grain.
Session-level summaries — one row per (target, filter, night). Frame count and total exposure rolled up to a session, useful for log-book-style records.
Aggregate totals — one row per (target, filter). Total integration hours, total frames, first and last seen. The headline numbers you'd quote on AstroBin or in a write-up.

All three are derived from the same source, so they always agree with each other and with the in-app dashboard.

CSV export (Pro)

From the Dashboard, choose Export › CSV and pick one of the three pre-built reports (Frames, Sessions, Totals). PL writes a file with stable column headers, RFC 4180 quoting (double-quote any field containing a comma, newline, or quote), and UTF-8 encoding without a BOM. The header row is always the first line.

The Frames report can get large — expect roughly one row per sub-frame in your archive. The Sessions and Totals reports are dramatically smaller and are usually what you want for sharing.

Sample CSV schemas

Column names below are illustrative — see the in-app exporter for the authoritative schema, which may add or rename fields over time.

Frames CSV

Column	Typical content
`path`	Absolute or archive-relative path to the FITS file
`target`	From `OBJECT` (e.g. `M81`)
`filter`	From `FILTER` (e.g. `Ha`, `L`, `R`)
`exposure_s`	From `EXPTIME`, in seconds
`image_type`	From `IMAGETYP` (Light / Flat / Dark / Bias)
`date_obs_utc`	From `DATE-OBS`, ISO 8601 UTC
`instrume`	From `INSTRUME` (camera)
`telescop`	From `TELESCOP` (OTA)
`focallen`	From `FOCALLEN`, in mm
`xbinning`	From `XBINNING`
`gain`	From `GAIN`
`ccd_temp`	From `CCD-TEMP`, in °C

Sessions CSV

Column	Typical content
`session_date`	Local astronomical night (YYYY-MM-DD)
`target`	Target name
`filter`	Filter name
`frame_count`	Number of light frames for this (target, filter, night)
`total_exposure_s`	Sum of `EXPTIME` across those frames
`instrume`	Camera used (or list, if mixed)
`telescop`	Telescope used (or list, if mixed)

Totals CSV

Column	Typical content
`target`	Target name
`filter`	Filter name
`total_hours`	Total integration in hours (decimal)
`frame_count`	Total light-frame count
`first_seen`	Earliest `DATE-OBS` for this pair
`last_seen`	Latest `DATE-OBS` for this pair

Integrating with external tools

Pandas — df = pd.read_csv("totals.csv") and you're done. Numeric columns parse straight to float/int; pass parse_dates=["date_obs_utc"] to get real datetime64s.
Excel / Numbers / LibreOffice — double-click the CSV. Column types are typically inferred correctly. If your locale uses comma as the decimal separator, import via the data wizard and pick UTF-8 + comma delimiter.
Grafana, Metabase, Superset — most BI tools can ingest a CSV directly or via a staging table. Load the Frames or Sessions CSV and build panels from there.
AstroBin — export Totals as CSV and copy the relevant target, filter, frame_count, total_hours rows into AstroBin's acquisition fields when you publish an image.

Free-tier note

CSV export is a Pro feature. The free tier indexes up to 5,000 frames in a local SQLite database and includes the in-app dashboard — plenty for evaluation and small archives. See pricing for the full split.