document TOFSense-M cascade metadata

README.md

@@ -86,6 +86,7 @@ raw/sessions/<session_id>/metadata.yaml        # session metadata
 raw/sessions/<session_id>/topic_summary.yaml   # per-topic statistics
 metadata/sessions.parquet                      # session index
 metadata/topics.parquet                        # topic index
+metadata/tof_sensor.yaml                       # TOFSense-M cascade metadata
 quality/reports/                               # generated quality reports
 calibration/robot_v1_template/                 # calibration files
 ```
@@ -130,9 +131,10 @@ calibration/robot_v1_template/                 # calibration files
 
 - Sessions missing RGB color topics: 7 (`2026-05-13_024746_odom_run001`, `2026-05-14_001841_odom_run008`, `2026-05-14_013615_odom_run012`, `2026-05-14_020913_odom_run015`, `2026-05-15_013500_odom_run019`, `2026-05-15_025645_odom_run022`, `2026-05-15_034810_odom_run024`).
 - Sessions missing ToF topic: 2 (`2026-05-13_025750_odom_run003`, `2026-05-13_033144_odom_run006`).
+- ToF sensor metadata: six-node Nooploop TOFSense-M cascade, UART query mode, 8x8 pixels per node. See `metadata/tof_sensor.yaml` and `metadata/tof_sensor.md`.
 - ToF validity report: 29,607,498/37,576,640 valid pixels (78.79%).
 - `quality/reports/topic_completeness_and_tof_validity.md` contains the detailed per-session report.
-- `calibration/robot_v1_template/` contains MAVROS IMU, MID360 LiDAR, and D430 infrared stereo camera calibration. Use the recorded `/camera/*/camera_info` topics for RealSense color/depth intrinsics. Fixed ToF extrinsic is not available in this dataset version.
+- `calibration/robot_v1_template/` contains MAVROS IMU, MID360 LiDAR, D430 infrared stereo camera calibration, and the explicit ToF extrinsic status. Use the recorded `/camera/*/camera_info` topics for RealSense color/depth intrinsics. Fixed ToF extrinsic is not available in this dataset version.
 
 ## Limitations
 

calibration/robot_v1_template/tof_to_base.yaml

@@ -1,5 +1,16 @@
 sensor: nlink_tofsensem_cascade
+manufacturer: Nooploop
+model: TOFSense-M
+sensor_type: time_of_flight_matrix_laser_ranger
 topic: /nlink_tofsensem_cascade
+ros_message_type: nlink_parser/TofsenseMCascade
+collection_configuration:
+  interface: UART
+  output_mode: query
+  cascade_nodes: 6
+  pixel_mode: 8x8
+  pixels_per_node: 64
+  expected_pixels_per_message: 384
 parent_frame: base_link
 child_frame: tof_frame
 calibration_status: unavailable

dataset.yaml

@@ -30,6 +30,9 @@ default_topics:
   tf: /tf
   tf_static: /tf_static
 
+sensor_metadata:
+  tof: metadata/tof_sensor.yaml
+
 quality_status:
   - unchecked
   - good

metadata/schema.md

@@ -41,3 +41,19 @@ All timestamps use nanoseconds (`ns`). The first version stores indexes only. Ra
 | `timestamp_min_ns` | `int64` | Earliest topic timestamp. |
 | `timestamp_max_ns` | `int64` | Latest topic timestamp. |
 | `category` | `string` | Topic category. |
+
+## `metadata/tof_sensor.yaml`
+
+Machine-readable metadata for the ToF sensor used by `/nlink_tofsensem_cascade`.
+
+Key facts:
+
+| Field | Description |
+| --- | --- |
+| `model` | Nooploop TOFSense-M. |
+| `collection_configuration` | Six-node UART query cascade in 8x8 mode. |
+| `message_layout` | ROS message and per-node/per-pixel fields. |
+| `distance_status_codes` | Meaning of `dis_status` values. |
+| `specifications` | Range, FOV, refresh rate, laser class, power, and interface limits. |
+
+See `metadata/tof_sensor.md` for the human-readable version.

metadata/sensors.yaml

@@ -23,3 +23,19 @@ topic_categories:
   TF:
     - /tf
     - /tf_static
+
+sensor_specs:
+  tof:
+    metadata_file: metadata/tof_sensor.yaml
+    description_file: metadata/tof_sensor.md
+    manufacturer: Nooploop
+    model: TOFSense-M
+    sensor_type: time_of_flight_matrix_laser_ranger
+    topic: /nlink_tofsensem_cascade
+    ros_message_type: nlink_parser/TofsenseMCascade
+    collection_configuration:
+      interface: UART
+      output_mode: query
+      cascade_nodes: 6
+      pixel_mode: 8x8
+      pixels_per_node: 64

metadata/tof_sensor.md

@@ -0,0 +1,84 @@
+# TOFSense-M ToF Sensor Metadata
+
+The dataset ToF topic is `/nlink_tofsensem_cascade`. It records a six-node Nooploop TOFSense-M cascade using UART query output in 8x8 mode.
+
+## Collection Configuration
+
+| Field | Value |
+| --- | --- |
+| Sensor model | Nooploop TOFSense-M |
+| Sensor type | Time-of-flight matrix laser ranging sensor |
+| ROS topic | `/nlink_tofsensem_cascade` |
+| ROS message | `nlink_parser/TofsenseMCascade` |
+| Interface | UART |
+| Output mode | Query |
+| Cascade nodes | 6 |
+| Pixel mode | 8x8 |
+| Pixels per node | 64 |
+| Expected pixels per cascade message | 384 |
+| Nominal refresh rate | 15 Hz per node in 8x8 mode |
+| UART baud rate | 921600 bps |
+
+## Message Layout
+
+`nlink_parser/TofsenseMCascade` contains `nodes`, an array of `nlink_parser/TofsenseMFrame0`.
+
+Each node has:
+
+| Field | Type | Meaning |
+| --- | --- | --- |
+| `id` | `uint8` | Module ID in the cascade |
+| `system_time` | `uint32` | Sensor-side system time |
+| `pixel_count` | `uint8` | Expected to be 64 in this dataset |
+| `pixels` | `TofsenseMFrame0Pixel[]` | Pixel data ordered from index 0 to 63 |
+
+Each pixel has:
+
+| Field | Type | Unit | Meaning |
+| --- | --- | --- | --- |
+| `dis` | `float32` | mm | Distance decoded by the current `nlink_parser` output |
+| `dis_status` | `uint8` | code | Per-pixel distance status |
+| `signal_strength` | `uint16` | raw count | Return signal strength; larger is stronger |
+
+For validity checks, treat a pixel as usable only when `dis_status == 0` and `dis > 0`.
+
+## Distance Status Codes
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Measurement usable |
+| 1 | Signal strength too low |
+| 2 | Phase target |
+| 3 | Target noise estimate too high |
+| 4 | Target consistency check failed |
+| 5 | Measurement not updated |
+| 6 | Wraparound not performed, usually the first measurement |
+| 7 | Rate inconsistent |
+| 8 | Current target signal strength low |
+| 9 | Large pulse valid range, possibly due to merged targets |
+| 10 | Usable measurement, but no target was detected in the previous detection |
+| 11 | Measurement inconsistent |
+| 12 | Target ambiguous |
+| 13 | Target detected but data inconsistent, usually when a secondary target exists |
+| 255 | Target not detected |
+
+## Sensor Specifications
+
+| Parameter | Value |
+| --- | --- |
+| Range at 600 lux | 1.5 cm to 4 m |
+| Range at 60K lux | 1.5 cm to 2 m |
+| Range at 100K lux | 1.5 cm to 1.2 m |
+| Distance resolution | 1 mm |
+| Typical ranging accuracy | +/- 1.5 cm |
+| Typical standard deviation | < 1 cm at 4 m indoors / 600 lux |
+| Field of view | 45 deg horizontal, 45 deg vertical, 65 deg diagonal |
+| Supported pixel modes | 8x8 and 4x4 |
+| Refresh rate | 15 Hz at 8x8, 60 Hz at 4x4 |
+| Laser wavelength | 940 nm |
+| Laser class | Class 1 |
+| Typical power | 670 mW |
+| UART supply voltage | 3.7 V to 5.2 V |
+| CAN supply voltage | 4.2 V to 5.2 V |
+
+The fixed ToF-to-base extrinsic is not available in this dataset version. Use `calibration/robot_v1_template/tof_to_base.yaml` for the explicit calibration status.

metadata/tof_sensor.yaml

@@ -0,0 +1,133 @@
+sensor_name: tof_cascade
+manufacturer: Nooploop
+model: TOFSense-M
+product_family:
+  - TOFSense-M
+  - TOFSense-M S
+firmware_version_from_manual: V2.0.2
+sensor_type: time_of_flight_matrix_laser_ranger
+
+dataset_topic:
+  topic: /nlink_tofsensem_cascade
+  ros_message_type: nlink_parser/TofsenseMCascade
+  node_message_type: nlink_parser/TofsenseMFrame0
+  pixel_message_type: nlink_parser/TofsenseMFrame0Pixel
+
+collection_configuration:
+  interface: UART
+  output_mode: query
+  cascade_nodes: 6
+  pixel_mode: 8x8
+  pixels_per_node: 64
+  expected_pixels_per_message: 384
+  nominal_refresh_hz_per_node: 15
+  uart:
+    baud_rate_bps: 921600
+    data_bits: 8
+    stop_bits: 1
+    parity: none
+    flow_control: none
+  protocol:
+    query_frame: NLink_TOFSense_Read_Frame0
+    output_frame: NLink_TOFSense_M_Frame0
+    byte_order: little_endian
+
+message_layout:
+  nodes:
+    type: array
+    expected_length: 6
+    fields:
+      id:
+        type: uint8
+        description: Module ID in the cascade.
+      system_time:
+        type: uint32
+        description: Sensor-side system time from the TOFSense-M frame.
+      pixel_count:
+        type: uint8
+        expected_value: 64
+      pixels:
+        type: array
+        expected_length: 64
+        order: row_major_index_0_to_63
+  pixel_fields:
+    dis:
+      type: float32
+      unit: mm
+      valid_when: dis_status == 0 and dis > 0
+      description: Distance decoded by the nlink_parser from the protocol integer scale.
+    dis_status:
+      type: uint8
+      description: Per-pixel distance status code.
+    signal_strength:
+      type: uint16
+      unit: raw_count
+      description: Return signal strength. Larger values mean stronger returns.
+
+distance_status_codes:
+  0: measurement_usable
+  1: signal_strength_too_low
+  2: phase_target
+  3: target_noise_estimate_too_high
+  4: target_consistency_check_failed
+  5: measurement_not_updated
+  6: wraparound_not_performed_usually_first_measurement
+  7: rate_inconsistent
+  8: current_target_signal_strength_low
+  9: large_pulse_valid_range_possible_merged_target
+  10: usable_but_target_not_detected_in_previous_detection
+  11: measurement_inconsistent
+  12: target_ambiguous
+  13: target_detected_but_data_inconsistent_usually_secondary_target
+  255: target_not_detected
+
+specifications:
+  ranging_range_m:
+    at_600_lux:
+      min: 0.015
+      max: 4.0
+    at_60000_lux:
+      min: 0.015
+      max: 2.0
+    at_100000_lux:
+      min: 0.015
+      max: 1.2
+  distance_resolution_mm: 1
+  typical_accuracy_cm: 1.5
+  typical_standard_deviation_cm: 1.0
+  typical_standard_deviation_condition: indoor_600_lux_at_4m
+  field_of_view_deg:
+    horizontal: 45
+    vertical: 45
+    diagonal: 65
+  supported_pixel_modes:
+    - mode: 8x8
+      pixels: 64
+      nominal_refresh_hz: 15
+    - mode: 4x4
+      pixels: 16
+      nominal_refresh_hz: 60
+  wavelength_nm: 940
+  laser_class:
+    iec_60825_1_2014: Class 1
+    gb_7247_1_2012: class_1_laser_product
+  power:
+    typical_power_mw: 670
+    supply_voltage_v:
+      uart:
+        min: 3.7
+        max: 5.2
+      can:
+        min: 4.2
+        max: 5.2
+  communication:
+    supported_interfaces:
+      - UART
+      - CAN
+    max_cascade_nodes:
+      uart: 8
+      can: 7
+
+manuals:
+  - TOFSense-M_Datasheet_V3.0_zh.pdf
+  - TOFSense-M_User_Manual_V3.0_zh.pdf

quality/reports/topic_completeness_and_tof_validity.md

@@ -2,7 +2,7 @@
 
 Generated from local ROS1 Docker by reading raw ROSBag files.
 
-Validity definition: a ToF pixel is valid when `dis_status == 0` and `dis` is finite and greater than 0. Distances are reported in the message unit, apparently millimeters.
+Validity definition: a ToF pixel is valid when `dis_status == 0` and `dis` is finite and greater than 0. Distances are reported in millimeters by the current `nlink_parser` output.
 
 ## Summary