ANNA 1B

About This Satellite

ANNA 1B launched on October 31, 1962 for geodesy, the measurement of Earth's shape, gravity field, and geographic reference framework. Its name reflects cooperation between the Army, Navy, NASA, and Air Force. It brought optical and radio techniques onto one satellite so measurements could help connect surveys across large distances.

Three observing techniques shared one orbiting target

The Army provided SECOR electronic ranging, the Navy supplied Doppler equipment and payload integration, and the Air Force developed the flashing-light system. NASA assisted the optical observation programme. Ranging measured distance, Doppler involved frequency changes, and cameras recorded beacon flashes. These were complementary observations, not three interchangeable versions of an Earth-imaging instrument.

A photograph of the beacon was not a photograph taken by the satellite

The optical experiment used geodetic cameras to record ANNA's flashes. The research report discusses the flash images on photographic plates and their use in connecting reference datums. In this measurement chain the satellite was the light source and the cameras were on the ground; illustrating it as an orbital camera mapping streets would reverse the experiment.

Mission reference: Air Force Cambridge Research Laboratories/NASA: Results From Satellite (ANNA) Geodesy Experiments. Editorial review: 2026-09-14.

A dimmer beacon changed the observing programme

The 1963 presidential space report records early power problems and a reduction of light intensity to about a quarter of the original level by January. Observations had to concentrate on a smaller US camera network. In July the light recovered when limited to roughly eight to ten flash sequences per day. Recovery therefore did not mean an unrestricted return to every originally planned observation.

Reference: US space activities report for 1963: ANNA 1B power limitations and recovery.

Optical tracking had its own documented observation record

NASA's 1966 technical note documents ANNA 1B observations from the Minitrack Optical Tracking System, or MOTS. This is a record of photographic tracking, separate from the satellite's Doppler and ranging measurements. For historical analysis, the observing system and successful observations matter alongside the spacecraft trajectory: being in orbit did not by itself guarantee that a camera recorded a useful beacon image.

Reference: NASA NTRS: NASA/MOTS optical observations of the ANNA 1B satellite.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 1,074 km at perigee to 1,179 km at apogee, a difference of 105 km. The orbital period is about 107.8 minutes. Eccentricity 0.00700 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.01 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.

Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.

Ground track is not sensor coverage

An inclination of 50.14 degrees implies approximate geocentric ground-track limits of 50.1 degrees north and south. This is a prograde orbit, moving in the same general direction as Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.

Accuracy and missing information

The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.

Catalog sources: CelesTrak SATCAT: NORAD 446 · GCAT: S00446 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.

Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)

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