PWS - KGYX Blockage Mitigation - Tree Survey Rev1.pdf

PERFORMANCE WORK STATEMENT (PWS) - Rev. 1

PROJECT: KGYX Radar Vegetation Management – Phase 1: Survey & Inventory WEATHER FORECAST OFFICE (WFO) LOCATION: 1 Weather Ln, Gray, ME 04039

RADAR COORDINATES: 43.891313° N, 70.256497° W

1. BACKGROUND

The National Weather Service (NWS) operates the WSR-88D Weather Radar (KGYX) in Gray, Maine. Radar beam blockage caused by surrounding vegetation is degrading data quality. The NWS is currently conducting a survey to determine the most cost-effective long-term solution:

removing the vegetation and/or raising the radar tower. To make this decision, the NWS requires a high-precision "Tree Inventory" that maps the vegetation against both the current tower height and a potential future tower height.

2. OBJECTIVE (CLIN 0001)

The Contractor shall provide a comprehensive geospatial inventory of all vegetation that obstructs—or threatens to obstruct—the radar's operational airspace. The primary objective is to generate a "Decision Matrix Dataset" that allows the Government to filter vegetation based on:

Vertical Threat: Will it block the current tower? Does it block the current tower? Will it block a future (+50 ft) tower?

Horizontal Ownership: Is it on State land (easy access) or Private land (complex access)?

3. SCOPE (CLIN 0001)

The Contractor shall provide all labor, equipment, and technical expertise to conduct a non-destructive aerial site survey utilizing a small Unmanned Aircraft System (sUAS) within a 1200-foot radius of the radar tower. The Contractor must hold an active FAA Part 107 Remote Pilot Certificate and ensure all flights comply with FAA regulations.

● In Scope: Acquisition of high-density aerial LiDAR data and imagery to generate a geospatial model of vegetation canopy height.

● Out of Scope: Physical tagging of trees, species identification, or collecting Diameter at Breast Height (DBH) data. This is strictly a data collection effort.

Rev. 1

4. PERFORMANCE REQUIREMENTS

4.1. Survey Boundaries (Horizontal Zones)

The Contractor shall survey vegetation within a maximum fixed radius of 1200 feet from the radar tower center point (43.891313, -70.256497). Within this 1200-foot operational circle, the Contractor shall attribute every inventoried tree to one of two "Stakeholder Zones" based on Land Ownership.

● ZONE A (State/Lessor-controlled land): Any land within the 1200-foot radius that is owned by the State of Maine or the land owner currently leasing to the Federal Government, October Corporation.

○ Operational Intent: This zone represents land where the NWS has existing or simplified access rights.

● ZONE B (Private/Other): Any land within the 1200-foot radius that does not meet the criteria for Zone A (e.g., private residential lots, commercial property).

○ Operational Intent: This zone represents land requiring complex individual landowner negotiations for future access.

4.1.1. Boundary Identification (Cadastral Awareness)

The Contractor acknowledges that the boundary between Zone A and Zone B is an irregular shape of property lines.

● Requirement: The Contractor shall identify approximate property boundaries digitally using available municipal tax maps and State of Maine GIS parcel data.

● Methodology: The Contractor shall overlay the GIS parcel data onto the final geospatial deliverables to broadly attribute inventoried vegetation to either Zone A or Zone B.

● Liability & Disclaimer: This boundary attribution is for internal Government planning and environmental assessment purposes only. It does not constitute a formal or legal property boundary survey. Therefore, a Maine Professional Land Surveyor (PLS) license is not required for this contract. Furthermore, the Contractor shall not conduct any physical tagging, marking, or monumentation on private property.

● Data Sourcing and Boundary Accuracy: The Government will not provide an authoritative or proprietary parcel dataset. The Contractor shall utilize publicly available municipal or county GIS parcel data (e.g., Cumberland County or Town of Gray tax assessor databases) to delineate the boundary between Zone A and Zone B. The Contractor is not required to employ a Professional Land Surveyor (PLS) to conduct a legal boundary survey. The GIS-derived boundaries are understood to be approximate and shall be used strictly for mitigation planning and to ensure ground-truthing personnel do not trespass into Zone B.

4.2. Vertical Classification Standards (The "Matrix")

The NWS defines the survey based on Mean Sea Level (MSL) elevation, not tree height above ground level.

● Vertical Datum: All data must be referenced to NAVD 88.

● Inventory Threshold: The Contractor shall inventory ONLY vegetation with a calculated

Tip Elevation (Ztip) greater than or equal to 448.0 Feet MSL (approx. 10 ft buffer below the critical plane).

Note on +50-Foot Threshold: Actual physical tower extensions are manufactured in standard metric increments (e.g., 15-meters). For the purposes of this survey's modeling and Tier classification deliverables, the '+50-foot' scenario is a standardized unit of measure used to calculate the hypothetical future threshold relative to the existing top plate.

The Contractor shall classify each inventoried tree into one of three "Threat Tiers" based on its Tip Elevation (Ztip):

Rev. 1

Tier Classification

Tip Elevation Criteria (Ztip)

Operational Definition

TIER 1 (RED) ≥ 508.0 ft

MSL

Critical Blockage. Obstruction persists even if the radar tower is raised ~50 ft (15m).

TIER 2

(ORANGE)

458.2 ft to <

508.0 ft MSL

Conditional Blockage. Obstructs the current tower, but would be cleared if the tower is raised.

TIER 3

(YELLOW)

448.0 ft to <

458.2 ft MSL

Growth Buffer. Future threat (5-10 years) to the current tower.

4.3. Verification of Reference Plane

Benchmark: The "Current Top Plate" elevation is estimated at 458.2 ft MSL.

Requirement: Prior to beginning the full survey, the Contractor shall measure the elevation of the radar tower's steel top plate (pedestal base) to verify this benchmark. If the field measurement differs by more than +/- 1.0 foot, the Contractor must contact the Contracting Officer's Representative (COR) for calibration.

4.4. LiDAR Data Specifications & Metrics

The Contractor shall provide a classified point cloud and derived surfaces meeting the following standards:

Point Density: Minimum of 8 points per square meter (ppsm) to ensure detection of individual tree crowns.

Vertical Accuracy: Root Mean Square Error (RMSE) of ≤10 cm to ensure precise "Tier" classification.

Classification: The point cloud shall be classified into standard ASPRS categories:

Class 2: Ground Class 3, 4, 5: Low/Medium/High Vegetation Class 6: Buildings/Structures (if applicable)

Canopy Height Model (CHM): A derived raster dataset representing the absolute height of vegetation above ground level.

4.5. Seasonal Timing (Leaf-On Acquisition)

To ensure the maximum canopy extent is captured for accurate obstruction modeling, the Contractor shall conduct all aerial LiDAR acquisition during "leaf-on" conditions (typically late spring through early fall).

4.6. Site Access, Coordination, and RF Hazard

The KGYX WSR-88D is an active weather radar emitting high-power Radio Frequency (RF) energy that can severely damage sUAS electronics. Prior to any flight operations, the Contractor must coordinate with the NWS Electronics Technician (El Tech) through the Contracting Officer's Representative (COR) to schedule a safe flight window. The radar will be placed in standby or sector-blanked during the Contractor's flight operations to ensure equipment safety.

5. DELIVERABLES

The Contractor shall provide the following deliverables:

ID Deliverable Name Format Description

D001 Classified Point Cloud

.LAS /

.LAZ

The raw 3D data containing all return pulses, fully classified (Ground vs.

Vegetation) and georeferenced to

NAVD 88.

D002 Vegetation

Obstruction Map (The "Heat Map")

GeoTIFF /

PDF

A color-coded raster map identifying vegetation that penetrates the critical height thresholds:

RED: Vegetation ≥ 508.0 ft MSL (Tier 1)

ORANGE: Vegetation 458.2 – 508.0 ft MSL (Tier 2)

YELLOW: Vegetation 448.0 – 458.2 ft MSL (Tier 3)

D003 Digital Surface Model (DSM) GeoTIFF

A raster dataset representing the absolute elevation of the highest vegetation canopy points, georeferenced to the NAVD 88 vertical datum (Above Mean Sea Level).

D004 Canopy Height Model (CHM) GeoTIFF

A derived raster dataset mathematically subtracting the bare earth elevation from the canopy top, representing the relative height of the trees (Above Ground Level).

D005 Survey Report PDF

Documentation of flight parameters, processing methodology, and vertical accuracy assessment against known ground control points.

D006 Vegetation Obstruction Table

.CSV /

.XLSX

A tabular spreadsheet of all inventoried trees meeting the threshold. Columns must include: ID, Latitude, Longitude, Tip Elevation (NAVD 88), Threat Tier (1, 2, or 3), and Ownership Zone (A or B).

6. PROJECT MANAGEMENT AND COMMUNICATION

Post-Award Kick-Off Meeting Within fourteen (14) days of contract award, the Contractor’s Project Manager shall schedule and conduct a virtual kick-off meeting with the Contracting Officer (CO), the Contracting Officer's Representative (COR), the KGYX Technical Point of Contact (TPOC), and the Radar Operations Center (ROC) Project Manager (PM). The purpose of this meeting is to align on the project schedule, verify FAA flight authorizations, and establish the communication protocol for coordinating site access and radar RF hazard mitigation.

Bi-Weekly Status Reporting The Contractor shall submit a brief written Status Report via email to the COR every two weeks throughout the Period of Performance. At a minimum, the report must include:

● Work completed during the previous two weeks (e.g., flight operations, data processing).

● Work planned for the upcoming two weeks.

● Any schedule risks or delays (e.g., weather grounding, equipment failure, or site access issues) and the Contractor's planned mitigation strategy.

Final Data Out-Brief Upon delivery of the Base Task (LiDAR Heat Map) datasets, the Contractor shall host a virtual Out-Brief meeting with the Government. The Contractor shall present the "Decision Matrix Dataset," demonstrate how the Canopy Height Model and Vegetation Obstruction Table were derived, and walk the NWS team through the identified threat tiers. Note: This out-brief is highly critical, as the Government will use this presentation to determine whether to formally exercise the Optional Forester Ground-Truthing). The Base Objective's (CLIN 0001) acceptance is a mandatory prerequisite for exercising the Option

(CLIN 0002).

7. GOVERNMENT FURNISHED INFORMATION (GFI)

● Site Access to 1 Weather Ln, Gray, ME.

● Contact information for the NWS Technical Point of Contact (TPOC) for coordination with

State and Private landowners.

● Attachment 1: Historical Site Survey (2016) – Provided for reference only; Contractor must verify current conditions.

● Attachment 2: NEPA CE Screening Checklist - The Government will provide the blank, standardized NOAA/NWS Categorical Exclusion environmental screening checklist that the Contractor’s Forester must complete if the Optional Objective (CLIN 0002) is exercised.

8. PERIOD OF PERFORMANCE

The Contractor shall complete all data acquisition and submit final deliverables within 90 Days of contract award.

9. PLACE OF PERFORMANCE

The physical, on-site data acquisition (flight operations and optional forestry ground-truthing) shall be performed at the KGYX WSR-88D Weather Radar Facility located at 1 Weather Ln, Gray, ME 04039, and the immediate surrounding 1200-foot survey radius. Post-processing of LiDAR data, GIS analysis, and report generation may be performed at the Contractor’s own facility. Optional forestry ground-truthing (CLIN 0002) activities shall be restricted strictly to Zone A.

9.1. Travel and Other Direct Costs (ODCs)

This is a Firm Fixed Price (FFP) contract. The Government will not provide separate, cost-reimbursable funding for travel, lodging, per diem, or mobilization. The Contractor is responsible for all travel and logistical arrangements required to execute the on-site portions of this PWS. All anticipated travel costs and ODCs must be fully burdened and included within the Contractor’s proposed firm fixed price for CLIN 0001 (and Optional CLIN 0002, if exercised).

10. OPTIONAL OBJECTIVE (CLIN 0002)

Note: This is an Optional Objective. The Government reserves the right to exercise this option at its discretion following the completion and acceptance of the Base Objective (CLIN 0001 - LiDAR Deliverables).

10.1. Scope of Optional Objective

Upon written notice to proceed from the Contracting Officer, the Contractor shall provide a Licensed Professional Forester (State of Maine) with a Natural Resource Management background to conduct a non-destructive, boots-on-the-ground assessment of individual Tier 1 and Tier 2 obstruction trees identified in the Base Objective.

Geographic Limitation: Ground-truthing activities for this CLIN are restricted entirely to ZONE A (State/Lessor-controlled land). Under no circumstances shall the Contractor or their Forester physically enter ZONE B (Private Land) to conduct inventory activities.

Strict Limitation: This contract is for data collection only. No vegetation is to be cut, damaged, felled, or permanently marked with paint. All markings must utilize GPS waypoints or temporary, biodegradable flagging.

10.2. Requirements

10.2.1. Targeted Timber Valuation & Inventory Update:

Utilizing the Base Objective "Vegetation Obstruction Table" (D006) and "Heat Map" (D002), the Forester shall navigate to each individual Tier 1 and Tier 2 obstruction located within Zone A.

The Forester shall update the provided D006 spreadsheet by appending the following field-collected data for every individual obstructing tree:

● Tree Species and estimated Diameter at Breast Height (DBH).

● Overall health/condition (e.g., identifying dead/dying snags).

● Estimated merchantable timber volume and current stumpage value to support the Government's Cost-Benefit Analysis.

10.2.2. NEPA Categorical Exclusion Screening:

The Forester shall complete the NEPA Categorical Exclusion Screening Checklist (Attachment

2) for the proposed harvest zones. This specifically requires:

● Endangered Species Assessment: Assess the stand for suitability as Northern Long-Eared Bat maternity roosting habitat (e.g., presence of snags, cavities, peeling bark) in accordance with 2024 USFWS guidelines.

● Wetland Verification: Ground-truth the presence of any vernal pools or wetlands not visible in the aerial LiDAR.

10.2.3. Validation of Environmental Constraints:

The Forester shall field-verify the specific environmental constraints identified in the historical 2016 Site Survey, including:

● Protected Hemlock Delineation: Re-delineate the boundaries of the "S3" Hemlock (Tsuga canadensis) communities using sub-meter GPS to confirm if the stands have expanded or suffered mortality since 2016. The Forester shall verify if the identified obstruction trees can be safely removed without damaging these strict Hemlock exclusion zones.

● Slope Feasibility: Assess the feasibility of hand-felling or cable-logging for targets located on steep slopes (15–25%) where heavy tracked machinery is prohibited.

● Specimen Tree Assessment: Locate "Specimen Trees" (>30" DBH) identified in the 2016 report that are located in Zone A. Because the Forester is already collecting individual timber data for all Tier 1 and Tier 2 obstructions, the Forester shall additionally flag any obstructing tree that meets this Specimen size criteria, provide a geo-tagged photograph of the tree, and note any specific neighborhood screening value, historical significance, or heightened removal complexity.

10.3. Optional Objective Deliverables

If this option is exercised, the Contractor shall provide:

ID Deliverable Name Format Description

D007 Harvest Feasibility & NEPA Report .PDF

A synthesis of the timber value, harvest method recommendations, specimen tree photos, and the signed

"Attachment 2" certifying whether the site meets criteria for a NEPA Categorical Exclusion.

D008 Updated Vegetation Obstruction Table .CSV

The final spreadsheet containing both the LiDAR metrics and the Forester's appended field data for Zone A only.

D009 Forester GIS Package .SHP / .KML

GPS polygons/points of the verified Hemlock exclusion boundaries, specimen trees, and proposed logging landing zones.

D010 Comprehensive Mitigation

GIS Package & Final Report

As Required

The Prime Contractor shall integrate the Forester's field data

(D009) and the updated Obstruction Table (D008) directly into the original LiDAR Base Objective datasets (D004 Heat Map and D005 Canopy Height Model). This final synthesized geodatabase and accompanying PDF map series must visually display the exact trees recommended for harvest, their timber value, the designated logging landing zones, and the strict environmental exclusion boundaries (e.g., Hemlock stands) in a single, unified operational picture.

10.4. Optional Objective Period of Performance

If exercised, the Period of Performance for the Optional Objective (CLIN 0002) shall be 30 Days commencing from the date the Option is formally exercised by the Contracting Officer.

APPENDIX A: ACRONYMS AND DEFINITIONS

CE: Categorical Exclusion. A category of actions under NEPA that do not individually or cumulatively have a significant effect on the human environment.

CHM: Canopy Height Model. A raster dataset representing the absolute height of the tree canopy above the bare earth ground level.

CLIN: Contract Line Item Number. A specific line item in a federal contract identifying a separable deliverable or service.

COR: Contracting Officer's Representative. The Government official responsible for the technical administration of the contract and accepting deliverables.

CSV: Comma-Separated Values. A standardized, plain-text spreadsheet file format.

DBH: Diameter at Breast Height. The standard method of expressing the diameter of the trunk of a standing tree.

DSM: Digital Surface Model. A raster dataset representing the absolute elevation of the highest features (like the tree canopy) relative to mean sea level.

FAA: Federal Aviation Administration.

GFI: Government Furnished Information. Data, maps, or documents provided by the Government to the Contractor to facilitate contract execution.

GIS: Geographic Information System. A computer system for capturing, storing, checking, and displaying data related to positions on Earth's surface.

KGYX: The ICAO identifier for the WSR-88D weather radar located in Gray, Maine.

KML: Keyhole Markup Language. A file format used to display geographic data in an Earth browser such as Google Earth.

LiDAR: Light Detection and Ranging. A remote sensing method that uses light in the form of a pulsed laser to measure variable distances to the Earth.

NAVD 88: North American Vertical Datum of 1988. The official vertical datum for the conterminous United States, representing elevation above mean sea level.

NEPA: National Environmental Policy Act. A U.S. environmental law that promotes the enhancement of the environment and established the CE process.

NOAA: National Oceanic and Atmospheric Administration.

NWS: National Weather Service.

ODC: Other Direct Cost.

PDF: Portable Document Format.

PLS: Professional Land Surveyor. A credentialed professional legally authorized to determine property boundaries.

ppsm: Points per square meter. A metric used to define the density and resolution of a LiDAR point cloud.

RF: Radio Frequency. The electromagnetic energy emitted by the WSR-88D radar system.

ROC: Radar Operations Center. The central support facility for the WSR-88D network, located in Norman, Oklahoma.

SHP: Shapefile. A popular geospatial vector data format for geographic information system (GIS) software.

sUAS: Small Unmanned Aircraft System. The FAA's formal designation for commercial drones weighing less than 55 pounds.

TPOC: Technical Point of Contact. The local Government subject matter expert (e.g., the local NWS Electronics Technician).

USFWS: United States Fish and Wildlife Service.

WFO: Weather Forecast Office. The local NWS facility (in this case, located in Gray, Maine).

WSR-88D: Weather Surveillance Radar - 1988 Doppler (also known as NEXRAD). The technical designation for the NWS weather radar system.