# DSM Data (Digital Surface Model) DSM (Digital Surface Model) data is one of Powerlily's most powerful features for accurate solar design. Automatically detect building heights, roof slopes, and angles using high-resolution 3D elevation data. ## What is DSM Data? Digital Surface Model (DSM) data is 3D elevation information that shows the height of every surface in an area, including: - Buildings and structures - Trees and vegetation - Terrain and ground elevation - Roof surfaces and features ### How DSM Works DSM data is captured using: - **LiDAR** (Light Detection and Ranging) - Laser-based measurements - **Photogrammetry** - Multiple aerial photographs processed into 3D models - **Satellite Imagery** - High-resolution satellite data This creates a detailed 3D map showing exact elevation at every point. ## Why DSM Data Matters ### Accuracy Manual estimation of building heights and roof slopes leads to errors. DSM data provides: - **Exact Heights** - Within centimeters of actual measurements - **Precise Slopes** - Accurate roof pitch calculations - **Correct Angles** - Proper orientation and tilt data - **Realistic Models** - True-to-life 3D representations ### Time Savings Without DSM: - Manually estimate building height from shadows - Guess roof slope from imagery - Calculate baseline orientation visually - Risk errors requiring site visits With DSM: - **One Click** - Automatic detection - **Instant Results** - Heights and slopes in seconds - **No Guessing** - Real measured data - **Fewer Site Visits** - Accurate remote assessments ### Professional Results DSM-powered designs: - **Impress Clients** - Accurate, professional proposals - **Reduce Callbacks** - Fewer "this doesn't fit" issues - **Streamline Permitting** - Accurate data for permits - **Improve Accuracy** - Better production estimates ## Using DSM Data ### Availability Press `L` in the design tool to check DSM availability: - **Green Checkmark** ✅ - DSM data available for this location - **Red X** ❌ - No DSM data available **Coverage:** DSM data is available for most of the United States, with expanding coverage globally. ### Loading DSM Data 1. Open the 3D Design Tool 2. Select your imagery 3. Press `L` or click **Load DSM** 4. Wait 2-5 seconds for data to load 5. DSM layer appears as overlay ### DSM Visualization When DSM is loaded, you'll see: - **Color-coded elevation** - Different heights shown in different colors - **Contour lines** - Elevation changes visible - **3D terrain** - Ground elevation changes - **Building heights** - Structures clearly defined ### Toggle DSM Visibility Press `L` again to: - **Show/Hide** DSM overlay - **Compare** with satellite imagery - **Design** with or without DSM visible > **Tip:** Toggle DSM off when placing panels for clearer view, toggle on when verifying heights ## Automatic Polygon Detection The most powerful feature of DSM data: automatically set polygon properties based on real elevation data. ### How Automatic Detection Works 1. **Draw Polygon** - Create a polygon on the roof surface 2. **DSM Analyzes** - System examines elevation data within polygon 3. **Calculates Properties** - Determines height, slope, and baseline 4. **Auto-Fills** - Properties automatically set ### What Gets Auto-Detected **Height** - Average elevation of polygon above ground - Accounts for multi-story buildings - Handles varying terrain elevation **Slope (Pitch)** - Actual roof angle in degrees - Calculated from elevation gradient - Matches real roof pitch **Baseline** - Reference edge for slope direction - Auto-aligned with roof orientation - Determines slope direction ### Using Auto-Detection #### Method 1: Auto-Detect During Drawing 1. Ensure DSM data is loaded (`L` key) 2. Enter drawing mode (`D` key) 3. Draw your polygon as normal 4. Complete the polygon 5. **Automatic** - Properties set instantly #### Method 2: Auto-Detect Existing Polygon 1. Select an existing polygon 2. Look for "Detect from DSM" button in properties panel 3. Click the button 4. Properties update automatically ### Benefits of Auto-Detection **Speed:** - No manual height input needed - No guessing roof slope - Instant configuration **Accuracy:** - Real measured data - Not estimates or guesses - Production calculations more precise **Consistency:** - Same method for all polygons - Reduced human error - Reliable results ## Understanding DSM Results ### Height Detection **What it shows:** - Height of roof surface above ground level - Measured in meters - Eave to ridge average **Example:** - Single story house: 3-4 meters - Two story house: 6-8 meters - Commercial building: 4-10+ meters ### Slope Detection **What it shows:** - Roof angle from horizontal - Measured in degrees - Standard industry format **Common Slopes:** - 0° = Flat roof - 5-10° = Low slope - 18-27° = Standard residential (4:12 to 6:12) - 30-45° = Steep residential **Pitch Conversion:** - 18° ≈ 4:12 pitch - 27° ≈ 6:12 pitch - 37° ≈ 9:12 pitch ### Baseline Detection **What it shows:** - Which edge is the reference - Direction roof slopes from - Critical for accurate 3D model **Impact:** - Affects 3D visualization - Changes how panels sit - Influences shading calculations ## DSM Data Quality ### High-Quality Indicators **Good DSM data shows:** - Sharp building edges - Clear elevation changes - Smooth roof surfaces - Distinct features **Results:** - Very accurate auto-detection - Reliable height and slope - Professional 3D models ### Lower-Quality Indicators **Less ideal DSM data shows:** - Fuzzy edges - Noisy elevation data - Irregular surfaces - Missing areas **What to do:** - Still use auto-detection as starting point - Verify with satellite imagery - Adjust manually if needed - Consider site visit for complex projects ## Best Practices ### When to Use DSM Auto-Detection **Always Use For:** - ✅ Standard residential roofs - ✅ Simple commercial buildings - ✅ New construction with recent imagery - ✅ Projects where accuracy matters most **May Need Manual Adjustment:** - ⚠️ Very complex roof lines - ⚠️ Multiple roof levels - ⚠️ Recent construction (DSM may be outdated) - ⚠️ Areas with poor DSM coverage ### Verification Steps **After Auto-Detection:** 1. **Visual Check** - Does 3D model look right? 2. **Compare Imagery** - Match with satellite view 3. **Logical Test** - Does height/slope make sense? 4. **Cross-Reference** - Check multiple roof sections **If Something Looks Wrong:** 1. Toggle DSM visibility to verify data quality 2. Check if polygon is correctly placed on roof 3. Try re-drawing polygon more precisely 4. Run auto-detect again 5. Manually adjust if needed ### Manual Override You can always override auto-detected values: 1. Auto-detect sets initial values 2. Edit any property manually in panel 3. Your manual values override DSM 4. Use when you have better information **When to Override:** - You have actual site measurements - Recent construction not in DSM - DSM data quality is poor - Complex roof requires adjustment ## Troubleshooting ### DSM Not Loading **Possible Causes:** - No DSM data for location - Internet connection issue - Imagery not yet selected **Solutions:** - Verify location has DSM coverage - Check internet connection - Ensure imagery is loaded first - Try refreshing page ### Incorrect Height Detection **Possible Causes:** - Polygon drawn on wrong surface - DSM data outdated - Terrain elevation affecting reading **Solutions:** - Redraw polygon precisely on roof - Verify with satellite imagery - Manually enter correct height - Check nearby reference buildings ### Incorrect Slope Detection **Possible Causes:** - Low-quality DSM data - Irregular roof surface - Polygon spans multiple roof planes **Solutions:** - Draw smaller polygons per roof plane - Verify slope visually from imagery - Use manual slope entry - Reference similar nearby buildings ### Baseline Wrong Direction **Possible Causes:** - Irregular polygon shape - Ambiguous roof orientation **Solutions:** - Press `R` to rotate baseline - Manually verify correct slope direction - Compare with satellite imagery - Use perpendicular edges as reference ## Advanced Techniques ### Multi-Level Buildings **Approach:** 1. Draw separate polygons for each level 2. Auto-detect each polygon individually 3. Each gets appropriate height 4. Results in accurate multi-level model ### Complex Roof Lines **Approach:** 1. Break complex roof into simple sections 2. One polygon per roof plane 3. Auto-detect each section 4. Combine for complete model ### Hip and Valley Roofs **Approach:** 1. Identify main roof planes 2. Draw polygon on dominant slope 3. Auto-detect gets primary angle 4. Use for production calculations ## DSM vs. Manual Entry ### DSM Auto-Detection **Pros:** - Fast and efficient - Objective measurements - Reduces human error - Professional results **Cons:** - Requires DSM availability - May need verification - Can't capture recent changes ### Manual Entry **Pros:** - Works anywhere - Can use site measurements - Full control over values - Handles any situation **Cons:** - Slower process - Requires estimation or measurements - More room for error - Depends on user expertise ### Hybrid Approach (Recommended) 1. **Start with DSM** - Auto-detect for speed and accuracy 2. **Verify Results** - Cross-check with imagery 3. **Adjust if Needed** - Manual override when appropriate 4. **Document Changes** - Note why manual adjustments made ## Coverage and Availability ### United States DSM data available for: - Most major metropolitan areas - Suburban regions - Many rural areas - Expanding coverage constantly **Best Coverage:** - California - Texas - Florida - Northeast corridor - Major cities nationwide ### International DSM availability expanding globally: - Canada - Major cities - Australia - Urban areas - Europe - Selected regions - Coverage improving regularly ### Checking Coverage To verify DSM availability for a specific location: 1. Enter location in design tool 2. Load imagery 3. Press `L` to check DSM 4. Green ✅ = available, Red ❌ = not available ## Future of DSM DSM data is constantly improving: **Better Resolution:** - Higher detail elevation data - More precise measurements - Smaller features detected **Wider Coverage:** - More geographic areas - Global expansion - Rural area coverage **More Current:** - More frequent updates - Newer imagery - Recent construction captured **Enhanced Features:** - Automatic tree detection - Obstruction identification - Intelligent defaults --- **See Also:** - [[Drawing Mode]] - Creating polygons - [[General Controls]] - Navigation and DSM shortcuts - [[Terminology]] - Understanding slope and angles