🔒 Your RSN coordinates cannot leave this page
Everything computes inside your browser — no server-side
processing, no upload, no database, no analytics, no third-party
code. Enforced, not promised: this page ships with a
Content-Security-Policy of
connect-src 'none', so the
browser itself refuses every network request the page could attempt
after loading. Open it, switch to flight mode, and it keeps working.
Pasted coordinates exist only in this tab's memory and are gone when
you close it — nothing is stored except the offset you type, which
stays on this device only.
1 · Paste the contractor CSV
prism = RSN + offset × (I,J,K)/|(I,J,K)| · Easting, Northing, Elevation, I, J, K — an optional name
column in front is fine; header rows are skipped
mm
typed once, applied to every
row · remembered on this device
Result — prism-centre coordinates
name, Easting, Northing, Elevation — no header row, exactly as the instrument wants it
Paste the contractor CSV above and press Calculate.