Apertide Star Profiles

Apertide is an offline star-profile inspector for iPhone and iPad. Import monochrome FITS frames, measure real candidates and take useful reports.

MEASURE YOUR FRAMES Detect up to 300 brightest local maxima. Inspect half-flux radius (HFR) in input pixels, flux-weighted centroid, second-moment roundness and an encircled-flux curve. Adjust the aperture from 6–24 px and threshold from 3–15 sigma. Edge, crowded, flat-core, undersampled and aperture-limited candidates are flagged and excluded. Manually exclude other false detections.

SEE THE FIELD A 3×3 mosaic shows the brightest accepted candidate in each region, its accepted count and the actual regional median HFR. Open the full-frame preview with candidate markers. Inspect any retained candidate's pixel crop and measurements.

COMPARE AND KEEP Keep 12 local studies with up to eight equal-dimension frames each. Rename studies, add notes and delete studies with their sources. Settings and manual exclusions persist on this device. Compare aggregate HFR, roundness and accepted counts. Normal first launch is empty. An optional original synthetic focus sweep is editable.

TAKE REAL REPORTS Generate and preview a PDF overview and per-frame mosaic pages. Share frame, candidate and region CSV, source SHA-256 hashes, full study JSON, mosaic PNGs and a derived-report ZIP. Original FITS files are not included. The ZIP is not an importable session backup.

SUPPORTED INPUTS Uncompressed single-primary 2D grayscale FITS, BITPIX 8, 16, 32, −32 or −64 with finite values. Maximum 4096 pixels per side and 140 MB per file; 512 MB total source storage. No image cubes, RGB/JPEG, extensions, BLANK pixels or compressed FITS.

MEASUREMENT LIMITS HFR uses positive background-subtracted flux within a finite aperture. Roundness is a second-moment axis ratio, not fitted Gaussian/Moffat FWHM. Candidates may be false detections. Comparison does not match or register the same stars. Use the same camera, binning, filter and conditions. Coordinates are zero-based; the first FITS row is displayed at the top. No WCS rotation. Regional differences do not diagnose tilt or backfocus. No telescope/camera connection, autofocus, astrometry or source editing.

One purchase. No subscription, account, ads, analytics or developer data upload.

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