Hyper-angular polarimeter · NASA ER-2 · flight planning
Projects the AirHARP2 field of view onto the ground and computes the scattering angle Θ between the sun and
every viewing direction — at the ER-2's live position from the NASA ASP feed, or anywhere along a planned KML route.
Footprint colored by ΘMasked HARP field of view with the 130–165° cloud-retrieval band highlighted.
Min · max · nadir ΘPer band, with Θ against along-track view angle across all sectors.
Click a pixelSee its multi-angle Θ across the whole overpass.
Whole-route stripΘ range available at every point of a KML flight.
Everything runs in your browser with the full HARP optical model. The map, the aircraft feed, and the first
calculation load only after you press Start.
AirHARP2 · Scattering Angle Planner
HARP optical model · vignetting-masked FOV
Source
LIVE · N806NA
Packet time UTC
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Age
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Lat / Lon
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Heading
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Ground speed
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Solar zenith · azimuth
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IWG1 –Sun below horizon
Auto-refresh every 60 s
Last packet (UTC)–
Waypoints0Length–End time (UTC)–
Click the map to add waypoints (as many as you like); drag a waypoint to move it;
double-click or press Finish to stop. Point 1 departs at the start time below.
Showinglatest availableSector–
10-minute imagery, native resolution ≈ 2 km (zoom 7); tiles load only while this is on.
Altitude and speed are filled from the aircraft packet (altitude is GPS MSL); edit either for a what-if, then recompute.
Scattering angle Θ over footprint
cloud 130–165°
Min
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Max
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Nadir
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Θ vs along-track view angle · band = cross-track spread
Full HARP optical model: view zenith = √(along² + cross²), great-circle projection d = h·tanθ,
ECEF view geometry; vignetting mask ≈ |along| ≤ 57°, |cross| ≤ 47°, θ ≤ 57°. Θ = 180° is exact backscatter.
Footprint pixels outside the cloud-retrieval range are dimmed.
Pixel hyper-angular Θ
click inside the footprint
Cross-track offset–
Θ seen at the selected ground pixel across the overpass (−57° aft … +57° fore), accounting for the
time the aircraft takes to fly the pass. Dots = the selected band's view sectors.
Position along route
max Θmin Θselected point
aircraftsun vectormasked FOV130–165° band
Tip: click anywhere inside the footprint to show the multi-angle (hyper-angular) scattering angle data for that pixel.