System Requirements Specification (SyRS) — ISO/IEC/IEEE 15289 — Specification | IEEE 29148 §6.2–6.4
Generated 2026-03-27 — UHT Journal / universalhex.org
| Standard | Title |
|---|---|
| ISO 11783-10 | — |
| Acronym | Expansion |
|---|---|
| ARC | Architecture Decisions |
| CCCS | Completeness, Consistency, Correctness, Stability |
| EARS | Easy Approach to Requirements Syntax |
| IFC | Interface Requirements |
| STK | Stakeholder Requirements |
| SUB | Subsystem Requirements |
| SYS | System Requirements |
| UHT | Universal Hex Taxonomy |
| VER | Verification Plan |
| Ref | Requirement | V&V | Tags |
|---|---|---|---|
| STK-NEEDS-001 | The Precision Agriculture Drone Fleet SHALL enable a single operator to survey and treat a minimum of 200 hectares per 8-hour operational day. Rationale: Derived from typical medium-scale US farm operational requirement. Below 200 hectares per day, cost per hectare makes drone application uncompetitive with ground sprayer rigs, undermining the economic case for the fleet. | Demonstration | stakeholder, session-216 |
| STK-NEEDS-002 | The Precision Agriculture Drone Fleet SHALL produce georeferenced crop health maps with a ground sample distance of 3 cm per pixel or finer, enabling identification of individual management zones of 0.1 hectare or smaller. Rationale: 3 cm GSD resolves individual crop rows and enables vegetation index computation at sub-management-zone granularity. 0.1 ha zone resolution matches the spatial precision of variable-rate application equipment. | Test | stakeholder, session-216 |
| STK-NEEDS-003 | The Precision Agriculture Drone Fleet SHALL comply with FAA Part 107 and applicable BVLOS waiver conditions, including Remote ID broadcast, throughout all flight operations. Rationale: Mandatory regulatory requirement for commercial UAS operations in US national airspace. FAA Part 107 BVLOS waiver conditions require continuous Remote ID broadcast. Non-compliance grounds the fleet and invalidates the operators certificate. | Inspection | stakeholder, session-216 |
| STK-NEEDS-004 | The Precision Agriculture Drone Fleet SHALL prevent off-target chemical drift beyond the treated field boundary under all approved operating conditions. Rationale: EPA label restrictions and state department of agriculture regulations require containment of pesticide applications within treated areas. Off-target drift creates liability exposure from damage to neighbouring crops, waterways, and sensitive habitats. | Test | stakeholder, session-216 |
| STK-NEEDS-005 | The Precision Agriculture Drone Fleet SHALL not operate over or within 30 metres of occupied structures, public roads, or neighbouring properties without explicit authorisation. Rationale: Derived from FAA Part 107 waiver conditions and agricultural chemical label buffer zone requirements. 30-metre exclusion zone provides safety margin for people and property in the event of chemical exposure or UAV malfunction. | Inspection | stakeholder, session-216 |
| STK-NEEDS-006 | The Precision Agriculture Drone Fleet SHALL support field-level maintenance and battery swap by a single technician without specialised tooling, with mean time to repair not exceeding 30 minutes for any line-replaceable unit. Rationale: Field operations at remote agricultural sites lack specialised tooling and depot-level maintenance capability. 30-minute MTTR ensures a single technician can maintain operational tempo without excessive fleet downtime during time-critical spray windows. | Demonstration | stakeholder, session-216 |
| STK-NEEDS-007 | The Precision Agriculture Drone Fleet SHALL import prescription maps from and export as-applied records to the farm's existing Farm Management Information System using standard agricultural data formats. Rationale: Farms operate existing precision agriculture data infrastructure such as John Deere Operations Center and Climate FieldView. Manual data re-entry between drone outputs and FMIS is error-prone and operationally unacceptable for time-critical variable-rate applications. | Demonstration | stakeholder, session-216 |
| STK-NEEDS-008 | The Precision Agriculture Drone Fleet SHALL maintain complete records of all chemical applications including product, rate, location, time, and weather conditions at time of application, retained for a minimum of 3 years. Rationale: EPA FIFRA recordkeeping requirements mandate retention of restricted-use pesticide application records including product, rate, location, and conditions. 3-year minimum aligns with federal and most state retention mandates. Incomplete records expose the operator to regulatory enforcement action. | Inspection | stakeholder, session-216 |
| Ref | Requirement | V&V | Tags |
|---|---|---|---|
| SYS-REQS-001 | The Precision Agriculture Drone Fleet SHALL achieve a sustained fleet spray throughput of at least 25 hectares per hour with a minimum of 4 drones operating simultaneously. Rationale: Derived from STK-NEEDS-001: 200 ha / 8 hr = 25 ha/hr. Four simultaneous drones provides N+1 redundancy for a three-drone minimum coverage rate and allows staggered battery swaps without throughput loss. | Test | system, session-216 |
| SYS-REQS-002 | The Precision Agriculture Drone Fleet SHALL achieve horizontal positioning accuracy of 10 cm CEP95 or better during all survey and spray flight operations using RTK-corrected GNSS. Rationale: 10 cm CEP95 required for precision application within 0.1 ha management zones (STK-NEEDS-002). At 5 m swath width, 10 cm cross-track error keeps spray overlap within design tolerance. RTK-corrected GNSS is the only positioning technology meeting this accuracy at UAS cost points. | Test | system, session-216 |
| SYS-REQS-003 | Each UAV in the fleet SHALL broadcast FAA Standard Remote ID messages at 1 Hz or greater, including serial number, position, altitude, velocity, and control station location, on both Bluetooth 5.0 and Wi-Fi Aware channels. Rationale: FAA Part 107 BVLOS waiver mandates Standard Remote ID broadcast (STK-NEEDS-003). 1 Hz minimum is the FAA-specified broadcast rate. Dual channel (BLE 5.0 + Wi-Fi Aware) ensures detectability by both FAA-approved receivers and law enforcement smartphone apps. | Test | system, session-216 |
| SYS-REQS-004 | The Spray Application Subsystem SHALL deliver the prescribed application rate within plus or minus 5 percent across each management zone, with automatic nozzle shutoff within 200 milliseconds of crossing a geofence boundary. Rationale: Plus or minus 5 percent rate accuracy is the agronomic standard for variable-rate application to avoid under-dosing (efficacy loss) or over-dosing (phytotoxicity and cost). 200 ms nozzle shutoff at 6 m/s ground speed produces 1.2 m overshoot, acceptable within the 3 m geofence margin. | Test | system, session-216 |
| SYS-REQS-005 | The Navigation and Flight Control Subsystem SHALL enforce geofence boundaries with a maximum overshoot of 3 metres under all wind conditions up to 25 knots, and SHALL prevent flight initiation if geofence data is not loaded. Rationale: 3 m geofence overshoot at maximum speed in 25 kt wind is physics-constrained by UAV deceleration capability. This value keeps the aircraft within the 30 m buffer zone required by STK-NEEDS-005 even in worst-case wind conditions. | Test | system, session-216 |
| SYS-REQS-006 | The Power and Battery Management Subsystem SHALL support battery pack replacement in 90 seconds or less per drone, either manually by a single operator or via the automated battery swap station. Rationale: 90-second battery swap derived from operational tempo analysis: at 30-minute endurance and 4-drone fleet, one drone lands every 7.5 minutes. 90 s swap time keeps turnaround below the inter-landing interval, preventing fleet idle time. Traces to STK-NEEDS-006. | Demonstration | system, session-216 |
| SYS-REQS-007 | The Data Processing and Analytics Subsystem SHALL import prescription maps in ISO-XML (ISO 11783-10) and ESRI Shapefile formats, and SHALL export as-applied records and vegetation index maps in both formats. Rationale: ISO-XML (ISO 11783-10) is the ISOBUS task controller data standard used by virtually all precision agriculture equipment. ESRI Shapefile is the de facto GIS interchange format. Supporting both ensures interoperability with existing FMIS without custom adapters (STK-NEEDS-007). | Test | system, session-216 |
| SYS-REQS-008 | The Precision Agriculture Drone Fleet SHALL automatically log each spray application with GPS track at 1 Hz, nozzle state, flow rate, product identity, ambient temperature, wind speed, wind direction, and relative humidity, stored in tamper-evident format for a minimum retention of 3 years. Rationale: 1 Hz GPS track logging captures application geometry at sub-metre resolution at typical spray speeds. Tamper-evident format with 3-year retention satisfies EPA FIFRA recordkeeping requirements and provides legal defensibility of application records (STK-NEEDS-008). | Test | system, session-216 |
| SYS-REQS-009 | The Precision Agriculture Drone Fleet SHALL maintain stable flight and spray operations in sustained winds up to 15 knots, and SHALL maintain stable flight without spray in winds up to 25 knots with automatic spray suspension above 15 knots. Rationale: 15 kt sustained wind is the agronomic threshold above which spray drift becomes uncontrollable for medium-droplet nozzles. 25 kt flight-only limit is the structural wind tolerance for this class of multi-rotor UAV. Auto-suspend prevents drift violation of STK-NEEDS-004. | Test | system, safety, session-216 |
| SYS-REQS-010 | Each UAV in the fleet SHALL achieve a minimum flight endurance of 30 minutes at maximum takeoff weight of 25 kg, including spray payload, in standard atmospheric conditions at sea level. Rationale: 30 minutes at 25 kg MTOW is the minimum viable sortie duration for agricultural operations. At 5 m/s ground speed and 5 m swath, a 30-min sortie covers approximately 4.5 ha. Shorter endurance makes battery turnaround dominate the operational day. | Test | system, session-216 |
| SYS-REQS-011 | When command-and-control link is lost for more than 5 seconds, each UAV SHALL execute the pre-programmed failsafe action (loiter for 30 seconds then return-to-home) with spray system automatically disabled. Rationale: 5-second C2 loss threshold filters transient link interruptions caused by terrain masking or interference without triggering premature failsafe. 30-second loiter provides time for link re-establishment before committing to RTH. Spray disable prevents uncontrolled chemical release during autonomous failsafe. | Test | system, safety, session-216 |
| SYS-REQS-012 | The Precision Agriculture Drone Fleet SHALL maintain a minimum separation distance of 20 metres between all UAVs during simultaneous operations, with automatic deconfliction commanding altitude separation or hold when separation cannot be maintained. Rationale: 20 m separation provides a 4x margin over RTK position uncertainty of 5 m. 30 m alert threshold at 5 m/s closing rate gives 2 seconds of manoeuvre time. These values balance collision avoidance safety with operational efficiency in adjacent-swath spray passes. | Test | system, safety, session-216 |
| SYS-REQS-013 | The Imaging and Remote Sensing Subsystem SHALL capture multispectral imagery at a ground sample distance of 3 cm per pixel or finer from a flight altitude of 50 metres AGL, across Blue, Green, Red, Red Edge, and Near-Infrared bands. Rationale: 3 cm GSD at 50 m AGL resolves individual crop rows for vegetation index computation. Five bands (Blue, Green, Red, Red Edge, NIR) cover NDVI, NDRE, and chlorophyll content index, which are the standard spectral indices for crop health assessment in precision agriculture. | Test | system, session-216 |
| SYS-REQS-014 | The Precision Agriculture Drone Fleet SHALL operate in ambient temperatures from 0 to 45 degrees Celsius, relative humidity from 20 to 95 percent non-condensing, and light rain up to 2 mm per hour with spray operations suspended during precipitation. Rationale: 0 to 45 degrees Celsius and 20 to 95 percent RH covers the growing season operating envelope across US agricultural regions from northern plains to southern states. Rain limit of 2 mm/hr protects spray efficacy (wash-off) and avionics (ingress), with spray suspension during precipitation. | Test | system, session-216 |
| SYS-REQS-015 | The Precision Agriculture Drone Fleet SHALL achieve a fleet-level operational availability of 85 percent or greater during planned operational days, with individual UAV MTBF of at least 500 flight hours. Rationale: 85 percent operational availability ensures profitable operations over a growing season where spray windows are limited. 500-hour MTBF per UAV, combined with 4-unit fleet and field-swappable LRUs, supports fleet scheduling without requiring excessive spare airframes. | Analysis | system, session-216 |
| SYS-REQS-016 | While executing spray flight paths, each UAV SHALL maintain cross-track error of 0.5 metres or less at ground speeds between 3 and 6 metres per second in winds up to 15 knots. Rationale: 0.5 m cross-track error at 3 to 6 m/s maintains spray overlap within 10 percent of design overlap, preventing missed strips (under-application) or double-application (phytotoxicity and cost). Speed range of 3 to 6 m/s matches typical spray application ground speed for agricultural drones. | Test | system, session-216 |
| Source | Target | Type | Description |
|---|---|---|---|
| STK-NEEDS-004 | SYS-REQS-016 | derives | |
| STK-NEEDS-006 | SYS-REQS-015 | derives | |
| STK-NEEDS-001 | SYS-REQS-014 | derives | |
| STK-NEEDS-002 | SYS-REQS-013 | derives | |
| STK-NEEDS-003 | SYS-REQS-012 | derives | |
| STK-NEEDS-003 | SYS-REQS-011 | derives | |
| STK-NEEDS-001 | SYS-REQS-010 | derives | |
| STK-NEEDS-004 | SYS-REQS-009 | derives | |
| STK-NEEDS-008 | SYS-REQS-008 | derives | |
| STK-NEEDS-007 | SYS-REQS-007 | derives | |
| STK-NEEDS-006 | SYS-REQS-006 | derives | |
| STK-NEEDS-005 | SYS-REQS-005 | derives | |
| STK-NEEDS-004 | SYS-REQS-004 | derives | |
| STK-NEEDS-003 | SYS-REQS-003 | derives | |
| STK-NEEDS-002 | SYS-REQS-002 | derives | |
| STK-NEEDS-001 | SYS-REQS-001 | derives |