LANDSAT 4

About This Satellite

Landsat 4 launched on July 16, 1982, carrying the new Thematic Mapper, TM, alongside MSS. It did not carry the older RBV camera system. This change expanded the spectral and spatial information available for land observation, making Landsat 4 more than a replacement vehicle with a new number.

Lower orbit, a new repeat pattern

The mission used a nominal 705 km orbit and a 16-day repeat cycle, replacing the higher orbit and 18-day pattern of Landsat 1-3. WRS-2 became its image-reference grid. These are original acquisition-design parameters, not a claim that a decommissioned spacecraft still maintains that orbit.

Do not align old scenes by path number alone

Because the reference grid changed, the same-looking path and row numbers are not sufficient evidence that early and later Landsat scenes cover an identical area. Use geographic footprints when comparing them. Otherwise, an apparent difference can come from comparing different places.

Mission reference: USGS: Landsat 4 and the Thematic Mapper. Editorial review: 2026-09-12.

Thermal resolution was not 30 metres

TM had seven bands. Its reflective observations had 30 m sampling, while its thermal band had 120 m sampling. A single resolution label hides this distinction. Thermal observations describe emitted radiation and require different interpretation from the reflected-light bands used in a colour image.

Reference: USGS: TM reflective and thermal sampling.

More wavelengths broadened the questions

The Landsat band guide shows how TM extended the earlier MSS spectral coverage with shortwave-infrared and thermal observations. For a comparison involving vegetation, water, or surface heat, choose bands by their wavelength and measurement type rather than copying a band number from another Landsat generation.

Reference: USGS: comparing Landsat spectral bands.

Reading this orbital snapshot

Based on TLE epoch: 2025-10-08. Estimated altitude ranges from 146 km at perigee to 160 km at apogee, a difference of 14 km. The orbital period is about 87.5 minutes. Eccentricity 0.00107 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.00 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 98.16 degrees implies approximate geocentric ground-track limits of 81.8 degrees north and south. This is a retrograde orbit, moving against the direction of 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 13367 · GCAT: S13367 (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)

Satellite Details