📖 Introduction & Architecture

JSMARS is an open-source, client-side web application providing high-performance geospatial data visualization, orbital tracking, planetary climatology, and geophysical modeling for Mars, the Moon, Earth, and Europa.

🚀 Getting Started

To use JSMARS locally or in production:

1. Open index.html in any modern browser (Chrome, Firefox, Safari, Edge) via an HTTP server or GitHub Pages.
2. Use the Sidebar on the left to toggle analytical tools, add base maps from USGS/OpenPlanetary WMS feeds, and customize layers.
3. Use the Panner Overview (bottom-right) or standard map controls to pan and zoom across the planetary surface.

⌨️ Keyboard Shortcuts

Use global keyboard shortcuts to quickly navigate the map, adjust zoom, manage sessions, and trigger GIS tools.

🌡️ 1D KRC Mars Thermal Simulation Model

The KRC engine is a client-side simulation (Hugh Kieffer KRC analog). It solves the 1D transient heat diffusion equation in Martian regolith coupled with surface radiative energy balance. Output is modeled temperature, not TES, THEMIS, or lander measurements.

Key Capabilities:

• Diurnal & Seasonal Curves: Simulates diurnal temperature swings ($T(t)$) and full orbital seasonal curves across Solar Longitude ($L_s = 0^\circ - 360^\circ$).
• CO2 Frost Condensation: Accurately clamps surface temperatures to the Clausius-Clapeyron dry ice condensation point ($T \approx 145-148\text{ K}$) and models sublimation mass flux.
• Two-Layer Apparent Thermal Inertia ($\Gamma_{\text{app}}$): Disentangles fine airfall dust mantles over high-conductivity volcanic basalt bedrock.
• Fourier Harmonics Deconvolution: Extracts fundamental harmonic amplitudes ($C_k$) and phase lag hours from diurnal temperature waves.

⏱️ Mars Time Slider & Orbital Ephemeris

Computes orbital mechanics, Keplerian true anomaly, Solar Longitude ($L_s$), Mars Year (MY), Mars Sol Date (MSD), and Local True Solar Time (LTST) using high-precision Allison & McEwen (2000) formulations.

💨 Mars Climate Database (MCD) Profiler

Offers an explicit choice of a 1D analytical physics model (offline) or live LMD MCD v6.1 GCM (climate model, not a spacecraft profile). If the live fetch fails, the analytical model is used and labeled Offline Fallback.

☄️ Crater Counting CSFD & Isochron Dating

Implements the Neukum Production Function (NPF 11th-order polynomial) and Hartmann-Neukum Mars Chronology Function to date planetary surface units:

💎 Educational Mineral-Index Visualizer

Approximate, client-side CRISM-style band-depth formulas (BD530 ferric iron, BD1900 hydration, BD1500 water ice, D2300 smectite, olivine index) rendered as illustrative overlays. Does not ingest per-pixel CRISM, OMEGA, or THEMIS cubes. Treat as a teaching visualizer until real multi-band rasters are wired in. Measured products: PDS CRISM and THEMIS archives.

🌐 3D Terrain & Globe Viewer (WebGL)

Renders regional elevation displacement meshes and 3D planetary globes with dynamic vertical exaggeration scaling ($1\times - 20\times$), real-time solar terminator illumination, Lambertian/Lommel-Seeliger/Minnaert photometric models, camera FOV ground swath width footprint ($W = 2 h \tan(\text{FOV}/2)$), and facet normals.

📡 Subsurface Radar Sounder (simulation)

Physically-based synthetic 2D B-scope radargrams and 1D A-scope traces using illustrative dielectric presets (Planum Boreum, Planum Australe, Medusae Fossae, Utopia Planitia, Europa ice-shell analogs). Not observed SHARAD, MARSIS, REASON, or RIME radargrams. Two-way travel time conversion $z = \frac{c \Delta t}{2 \sqrt{\epsilon_r}}$ is a model. For measured data see the PDS Geosciences Node SHARAD and MARSIS archives.

🚀 Interplanetary Astrodynamics & Trajectories

Calculates heliocentric Hohmann transfer orbits, Trans-Mars Injection ($\Delta v_1$), Mars Orbit Insertion ($\Delta v_2$), characteristic launch energy ($C_3$), synodic transfer opportunities, and Areostationary synchronous orbit altitudes.

⛰️ Topographic Contours, Slopes & Landing Hazards

Generates client-side Marching Squares elevation isocontours, 3x3 Zevenbergen-Thorne slope & aspect gradients, Topographic Wetness Index (TWI), Stream Power Index (SPI), and automated landing site hazard safety classification.

🗺️ Map Projections & Coordinate Systems

Supports Cylindrical Equirectangular, North/South Polar Stereographic, Albers Equal-Area Conic, Lambert Azimuthal Equal-Area, Sinusoidal, and Mollweide projections with real-time coordinate transformations across $0^\circ-360^\circ\text{ E}$, $\pm 180^\circ$, and West longitude.

📍 Investigate Probe Tool & Potential Fields

Click anywhere on Mars or the Moon to probe MOLA DEM elevations, WMS layer attributes, Complete Bouguer gravity anomalies ($\Delta g_B$), Airy-Heiskanen isostatic crustal roots ($t_{\text{root}} = h \frac{\rho_c}{\rho_m - \rho_c}$), and thermal diffusivity ($\kappa = \frac{k}{\rho c_p}$).

📏 Geodesy & Distance Measurements

Calculates planetary radius-calibrated geodesic line lengths, closed polygon surface areas, great-circle waypoint interpolation, cross-track/along-track offsets, direct destination points, and 3D interior straight-line tunnel chords.

✏️ Vector Shapes (ROIs) & GIS Formats

Digitize points, polylines, polygons, circles, and bounding boxes. Export to GeoJSON, CSV, WKT (Well-Known Text), and generate 6-line affine transformation world files (.pgw / .jgw) for QGIS, ArcGIS, and GDAL.

🏷️ Planetary Nomenclature & Gazetteer

Search over thousands of IAU official planetary landmarks across Mars and the Moon, filter by morphological feature type (craters, mons, valles, chasmata, planitiae), and recenter the map with one click.

🗂️ Layer Manager & Overlays

Reorder layer stacking via drag-and-drop, adjust transparency with real-time opacity sliders, toggle adaptive coordinate graticules, north arrows, and physical scale bars.

💾 Session Management & Serialization

Save entire workspaces—including active layer stack, opacity settings, viewport center, zoom, spatial bookmarks, measurements, and vector shapes—into compact JSON session files with instant restore.